Reciprocity and the Law of War - Harvard International Law ... · Reciprocity and the Law of War...

\\server05\productn\H\HLI\50-2\HLI205.txt unknown Seq: 1 25-JUN-09 7:50

VOLUME 50, NUMBER 2, SUMMER 2009

Reciprocity and the Law of War

Sean Watts*

This Article examines how the principle of reciprocity operates within the international law of war.Tracing the historical development and application of the law, the Article demonstrates that the existinglaw of war derives from a set of rules that are contingent on reciprocity. Contrary to common understand-ing, reciprocity strongly influences states’ interpretation and application of the law of war. The Articlefirst identifies an obligational component of reciprocity that restricts operation of the law to contestsbetween parties with parallel legal commitments. Second, the Article identifies an observational componentof the principle of reciprocity that permits parties to suspend or terminate observance when confronted withbreach. Although the principle of reciprocity was softened by late twentieth century legal instruments, itcontinues to form a critical component of the law of war and guides both pragmatic and theoreticaldiscourse. Regardless of normative conclusions about reciprocity as a precondition to application of the law,the Article’s reciprocity-cognizant framework for understanding the law of war provides a useful platformfor reform efforts.

Observe what Justice is and what Reciprocity. In my opinion,Justice rules between individuals, Reciprocity between States.Justice regulates rights and duties, and is a single entity—majes-tic, powerful, impartial. She wears a bandage over her eyes, andregards neither personalities nor Reciprocity. On the other hand,Reciprocity proclaims to the whole world: “I am not Justice, andI pay no regard to her. I am the Goddess of the Market and havemy eyes open, and in the market of the nations I myself am theprice of Justice.”1

Wyndham A. Bewes

I. INTRODUCTION

The principle of reciprocity has long been foundational to internationallaw and the law of war specifically.2 Reciprocity has a particularly strong

† Assistant Professor of Law, Creighton University School of Law, and Professor, The U.S. ArmyJudge Advocate General’s School, Army Reserve (DIMA). I wish to thank Professors Michael Kelly,Palma Strand, and Geoff Corn as well as Lieutenant Colonels Eric Talbot Jensen and Thomas “Mick”Wagoner for generous reviews and input on a draft of this Article. I would also like to thank ColleenMcGarry and Erin McManis for their excellent research assistance.

1. Wyndham A. Bewes, Reciprocity in the Enjoyment of Civil Rights, 3 PROBLEMS OF THE WAR 133, 133(1917) (external quotation marks omitted).

2. Jurists, soldiers, and policymakers are by now familiar with the question of how best to refer to thelaw regulating the conduct of hostilities, or jus in bello. Momentum appears to favor the term “Interna-tional Humanitarian Law” (“IHL”) as a replacement for the traditional term “Law of War” or its modernvariants, “Law of Armed Conflict” and “Law of International Armed Conflict.” See YORAM DINSTEIN,THE CONDUCT OF HOSTILITIES UNDER THE LAW OF INTERNATIONAL ARMED CONFLICT 2 (2004). Com-


366 Harvard International Law Journal / Vol. 50

intuitive appeal as a condition on war rules. Few would consider practicablea legal regime that required one side to “fight with one hand tied behind itsback” while its enemy exercised free reign.3 Until recently, reciprocity hasbeen an important tool in marketing the law of war to its end users: combat-ants and commanders.4 The U.S. Military’s law of war training routinelyincludes inducement of reciprocity by adversaries as one of many reasons forintegrating international law into military doctrine and operations.5 TheArmy’s law of war instructional materials caution soldiers to this effect.6

Conditions of reciprocity pervade modern law of war treaties and theirforebears. The pre- and post-Westphalian customs that formed the ground-work of the law of war reflected exclusive codes rather than universal moralnorms. As such, they were highly susceptible to suspension in cases of per-

mentators have offered competing justifications for adopting each term. In my presentations and instruc-tion on jus in bello, I have used each term, usually out of consideration for my particular audience. Onbalance, however, I have found arguments offered for retaining the term “Law of War” most persuasive.Foremost, the term “Law of War” best directs attention to the soldiers and combatants that bear thehardship and personal danger of its implementation. Although the term IHL undoubtedly embodies thelongstanding goal of humanizing warfare, it conveys a unitary purpose not vindicated by either thehistory or letter of the law itself. Indeed, one of the goals of this piece is to highlight that practicalmilitary concerns, including emphasis on internal discipline, merit equal billing with concerns of hu-manity. In fact, the two are in some respects mutually supporting.

3. Sir Lauterpacht has observed similarly, “[I]t is impossible to visualize the conduct of hostilities inwhich one side would be bound by rules of warfare without benefiting from them and the other sidewould benefit from rules of warfare without being bound by them.” Hersch Lauterpacht, The Limits of theOperation of the Law of War, 30 BRIT. Y.B. INT’L L. 206, 212 (1953); see also Alan Dershowitz, Should WeFight Terror with Torture?, THE INDEPENDENT, July 3, 2006 (quoting Aharon Barak, President of theSupreme Court of Israel), available at http://www.independent.co.uk/news/world/americas/alan-dershowitz-should-we-fight-terror-with-torture-406412.html.

4. The U.S. Navy publishes a legal guide for its commanders. DEP’T OF THE NAVY, ANNOTATED

SUPPLEMENT TO THE COMMANDER’S HANDBOOK ON THE LAW OF NAVAL OPERATIONS, NWP1-14M/MCWP5-2.1/COMDTPUB P5800.1 (1997). The guide observes, “Some obligations under the law ofarmed conflict are reciprocal in that they are binding on the parties only so long as both sides continue tocomply with them.” Id. at 6–21. The Handbook excludes rules of a humanitarian nature from the condi-tion of reciprocity and reserves non-reciprocity-based suspension of law to the National Command Au-thority. Id.

5. A U.S. Army training circular, written to help commanders conduct routine law of war instruction,remarks, “Observing these rules will encourage the enemy to do the same, increase the chances of anenemy surrender, and make the return to peace easier.” HEADQUARTERS, DEP’T OF THE ARMY, INSTRUC-

TOR’S GUIDE, THE LAW OF WAR, TRAINING CIRCULAR 27–10–3, at 4 (1985) [hereinafter U.S. ARMY

LAW OF WAR INSTRUCTOR’S GUIDE]; see also U.S. Army Center for Law and Mil. Operations, Annual Lawof War Briefing, Slide 5 (on file with author) (advising soldiers that adherence to the law of war provokesreciprocal adherence by enemies); Briefing, The Judge Advocate General’s School, The Framework of theLaw of War (July 7, 2008) (on file with author) (remarking that observing the law of war encouragesreciprocal treatment and observance by enemy forces).

6. U.S. ARMY LAW OF WAR INSTRUCTOR’S GUIDE, supra note 5, at 25. The Guide poses the following Rquestion in a section of sample questions and answers:

Question: Why should we obey the Hague and Geneva conventions when the enemy does notobey them?Answer: As soldiers, you obey these rules because the commander-in-chief requires you to obeythem . . . . Our standards are set; we will not lower them by accepting the reprehensiblestandard of our enemies . . . . Moreover, strict adherence to these rules may pressure the enemyinto complying with the requirements of the Conventions.

Id.


2009 / Reciprocity and the Law of War 367

ceived military necessity or in conflicts with enemies from foreign culturaland religious traditions. For their part, early law of war treaties includedreciprocal commitment to and reciprocal observance of the law of war aspreconditions to their operation. Even after explicit and often draconian con-ditions on reciprocity fell out of favor, reciprocity persisted beneath the sur-face of the law of war. Limits on application, requirements of stateaffiliation, and conditions on armed groups’ conduct and characteristics con-tinued to limit operation of the law of war. Such conditions operated simi-larly to conditions of reciprocity by effectively denying application of thelaw of war to all but peer competitors committed to reciprocal observance ofthe law of war.

Against this strong historical and textual tradition, some have arguedthat reciprocity is no longer a condition of the modern law of war. Groundedprimarily in the theory that the nature of the law of war has changed—thatrestraint in war is based no longer on promissory compromises between sov-ereigns—this view has gained significant traction and influenced the inter-pretive approaches of a number of legal authorities. Adherents of thismodern view support their claims with compelling textual and normativearguments.7 Thus jurists and policymakers who give primacy to sovereignty,national security, and adherence to limits on the operation and scope of thelaw of war have clashed with those who seek to humanize war furtherthrough evolution or even reconceptualization of the law.

Reciprocity is underappreciated as an element of disagreement in thisclash of views. Shared misunderstandings about the nature of the existinglaw and failure to appreciate persistent strains of reciprocity in the law ofwar explain some disagreement over and disappointment with the law. Thetension between these views presents an opportunity to assess how reciproc-ity has shaped the existing law of war and what role, if any, it should con-tinue to play.

Reciprocity continues to form a critical component of the law of war andstructures both theoretical and pragmatic discourse. As recently as 2002, theUnited States explicitly cited concerns of non-reciprocity in its decision todeny application of the law of war to Taliban fighters in Afghanistan.8 This

7. See INGRID DETTER, THE LAW OF WAR 404 (2d ed. 2000) (highlighting for purposes of discussionMichael Bothe’s view on reciprocity in Michael Bothe, Les Conflicts, REVUE GENERAL DE DROIT INTERNA-

TIONAL PUBLIC 93 (1978)); 1 JEAN-MARIE HENCKAERTS & LOUISE DOSWALD-BECK, CUSTOMARY INTER-

NATIONAL HUMANITARIAN LAW 498 (2005) (“The obligation to respect and ensure respect forinternational humanitarian law does not depend on reciprocity.”); FRANCOISE BOUCHET-SAULNIER, THE

PRACTICAL GUIDE TO HUMANITARIAN LAW 187 (Laura Brav & Clementine Olivier trans., Rowan &Littlefield Publishers, Inc., 2d ed. 2007) (2006).

8. See Decision re Application of the Geneva Convention on Prisoners of War to the Conflict with Al-Qaeda and the Taliban, Memorandum from Alberto R. Gonzales, Counsel to the President, Office ofCounsel to the President, to George W. Bush, President of the United States (Jan. 25, 2002), reprinted inTHE TORTURE PAPERS 118, 121 (Karen J. Greenberg & Joshua L. Dratel eds., 2005); Memorandum fromJay S. Bybee, Assistant Attorney Gen., Office of Legal Counsel, Dep’t of Justice, to Alberto R. Gonzales,Counsel to the President, and William J. Haynes II, Gen. Counsel of the Dep’t of Def., Application of



Article suggests that a productive reform dialogue must include a reciproc-ity-cognizant understanding of the law of war.

This Article offers three conclusions about reciprocity that will facilitatedebate over the current and future law of war. First, the law of war has longbeen conditioned on notions of reciprocal obligation and observation. Evenas formal mechanisms have faded from use, similarly-minded limits on theoperation of the law have persisted below the surface, vindicating the sameconcerns that informed traditional insistence on reciprocity. Second, stateshave recently shown a willingness to adapt the principle to changing con-ceptions of humanity in warfare. In particular, rules on treaty interpretationthat minimize the role of reciprocity have fostered widespread agreementthat many law of war provisions operate as obligations owed erga omnes ratherthan as bilateral concessions of a contractual nature. In both the law of warand human rights law, states have consented to peremptory norms that arenot subject to traditional reservations of reciprocity. Finally, this Articleobserves that the law of war has failed to keep pace with the evolution ofhow and why states fight. Insistence on reciprocity, grounded in early andmid-twentieth century law of war treaties, increasingly clashes with states’own strategic and tactical responses to conflict and may distract from mili-tary and political effectiveness. An analysis of the law of war that considersthe impact of reciprocity could resolve the current theoretical and doctrinaldebate over conflict regulation.

II. THE PRINCIPLE OF RECIPROCITY

French legal scholar Louis Le Fur observed that reciprocity lies at the rootof all international law.9 Le Fur’s observation was characteristic of earlytwentieth century scholarship and political views about international law.10

Treaties and Laws to al Qaeda and Taliban Detainees (Jan. 22, 2002), reprinted in THE TORTURE PAPERS

81, 103 (Karen J. Greenberg & Joshua L. Dratel eds., 2005) [hereinafter Bybee Memorandum]. Evaluat-ing whether the Geneva Conventions applied to the 2001 armed conflict with Afghanistan, the Office ofLegal Counsel observed, “If Afghanistan could be found in material breach for violating ‘a provisionessential to the accomplishment of the object or purpose of the [Geneva Conventions],’ suspension of theConventions would have been justified.” Id.

9. FRITS KALSHOVEN, BELLIGERENT REPRISALS 24 (1971) (referencing LOUIS LE FUR, DES REPRESAIL-

LES EN TEMPS DE GUERRE (1919)). Later writers confirm the pervasiveness of reciprocity in the interna-tional system. Elisabeth Zoller notes that reciprocity was a central principle of primitive life. ELISABETH

ZOLLER, PEACETIME UNILATERAL REMEDIES 14 (1984). Lacking hierarchies, primitive tribes relied onreciprocity to order relations between equal members. Id. (citing BRONISLAW MALINOVSKY, CRIME AND

CUSTOM IN SAVAGE SOCIETY (1926)). Zoller concludes that the international legal system is in somesenses a similarly primitive legal system, lacking de jure hierarchies and authorities and thus reliant onreciprocity to govern relations. Id.

10. See, e.g., PASQUALE FIORE, INTERNATIONAL LAW CODIFIED AND ITS LEGAL SANCTIONS 325 (EdwinM. Borchard trans., Baker, Voohis & Co. 1918) (1890) (observing that states alone can establish particu-lar rules for their relations by reciprocal agreement); WILLIAM EDWARD HALL, A TREATISE ON INTERNA-

TIONAL LAW 408 (A. Pearce Higgins ed., 8th ed. 1924) (“It is obviously an implied condition of theobligatory force of every international contract that it shall be observed by both of the parties to it.”);OPPENHEIM’S INTERNATIONAL LAW 579 (2d ed. 1912) (“Violation of a treaty by one of the con-



Reciprocity was an essential component of the system of sovereign, de jureequals. The prominence of reciprocity was especially apparent in diplomacy,the primary medium of state interaction.11 For instance, states frequentlyincluded conditions of reciprocity in the immunities and privileges they af-forded diplomatic personnel and public property.12 In 1938, the BritishHouse of Lords observed that the customary immunity recognized betweenstates could “be taken to flow from reciprocity, each foreign state within thecommunity of nations accepting some subtraction from its full sovereigntyin return for a similar concession on the side of the others.”13

International relations theorists have developed complex models to ex-plain how reciprocity shapes states’ interactions.14 Seeking to resolve ambi-guity inherent in the principle,15 Robert Keohane identifies two

tracting States does not ipso facto cancel such treaty, but it is in the discretion of the other party to cancelit on the ground of violation.

11. D.W. Greig, Reciprocity, Proportionality, and the Law of Treaties, 34 VA. J. INT’L L. 295, 298–99(1994). Sovereign immunity “ ‘may be taken to flow from reciprocity, each sovereign State within thecommunity of nations accepting some subtraction from its full sovereignty in return for similar conces-sions on the side of the others.’ ” Id. at 299 (quoting Compania Naviera Vascongada v. S.S. Cristina[1938] A. C. 485 (U.K.)).

12. In 1961, the International Law Commission (“ILC”) issued a recommendation for an internationalconference on consular relations. The ILC draft articles sparked discussion regarding reciprocity. Specifi-cally, states disagreed about how to apply the Conventions to consular delegations. Whereas the ILCpreferred to insulate delegations from reciprocity-based limitations, states ultimately preserved a measureof reciprocity through an article on non-discrimination. The article states:

1. In the application of the provisions of the present Convention the receiving State shall notdiscriminate as between States.2. However, discrimination shall not be regarded as taking place:(a) where the receiving State applies any of the provisions of the present Convention restric-tively because of a restrictive application of that provision to its consular posts in the sendingState;(b) where by custom or agreement States extend to each other more favourable treatment thanis required by the provisions of the present Convention.

Vienna Convention on Consular Relations art. 72, Apr. 24, 1963, 21 U.S.T. 77, 596 U.N.T.S. 261; seealso Herbert Briggs, Codification Treaties and Provisions on Reciprocity, Non-Discrimination or Retaliation, 56AM. J. INT’L L. 475, 475 (1962); Ernest L. Kerley, Some Aspects of the Vienna Conference on DiplomaticIntercourse and Immunities, 56 AM. J. INT’L L. 88, 98–99 (1962).

13. Arthur Lenhoff, Reciprocity: The Legal Aspect of a Perennial Idea, 49 NW. U. L. REV. 619, 623(1954) (quoting Compania Naviera Vascongada v. S.S. Cristina [1938] A. C. 485 (U.K.)). Lenhoff alsonotes a contemporaneous British extension of reciprocal immunity to the then-insurgent, de facto Francogovernment in Spain. Id. (citing The Arantzazu Mendi [1939] A. C. 256).

14. See Robert O. Keohane, Reciprocity in International Relations, 25 INT’L ORG. 1 (1986). Reciprocityas a condition for observance of international law fits well with rational choice and state interest compli-ance and formation theories for international law. Even international law skeptics admit the role ofreciprocity in conditioning states’ relations. Professors Goldsmith and Posner posit reciprocity-condi-tioned “cooperation” as one of four models of state behavior associated with international law. JACK L.GOLDSMITH & ERIC A. POSNER, THE LIMITS OF INTERNATIONAL LAW 12 (2005). The four models in-clude: coincidence of interest (two states pursuing compatible goals without consulting the other), coordina-tion (agreement on and pursuit of similar interests), cooperation (“[S]tates reciprocally refrain fromactivities . . . that would otherwise be in their immediate self-interest in order to reap larger medium- orlong-term benefits.”), and coercion (use of force to bend another state to act contrary to its own interests).Id. at 12.

15. Alvin Gouldner notes that a number of important sociological studies of reciprocity decline todefine the principle. Alvin W. Gouldner, The Norm of Reciprocity: A Preliminary Statement, 25 AM. SOC.



manifestations of reciprocity in international relations, distinguished by thenature and level of interaction involved. They are “specific reciprocity” and“diffuse reciprocity.”

Specific reciprocity describes situations in which actors in a bilateral rela-tionship trade items or acts of roughly equivalent value in a sequential ex-change or interaction.16 Contracts are clear examples of specific reciprocity,as they operate through promissory exchanges of similarly valued goods orservices. Keohane notes that while specific reciprocity is a temperamentalform of cooperation that can frustrate those who seek stable, beneficialagreements, it can ensure cooperation in the anarchic world of internationalrelations.17 Arrangements based on specific reciprocity are typically tempo-rary and often isolated. Consistent with realist skepticism, specific reciproc-ity discounts promissory arrangements as merely epiphenomenal evidence ofmomentary state interest, rather than reflective of lasting or meaningfullybinding norms on state behavior.

Diffuse reciprocity describes interactions between a state and a group,rather than an individual actor or peer.18 Keohane notes that diffuse reci-procity’s broader scope of commitment to accepted standards of behaviorreduces unnecessary and inefficient conflict. Yet he cautions that diffuse rec-iprocity can only be achieved where the actors share compatible interests andnorms of obligation.19 Absent these prerequisites, diffuse reciprocity exposesparties to exploitation.20

Thus while the principle of reciprocity is recognized as a general tenet ofinternational law, it does not operate uniformly across the spectrum of inter-national relations. Legal scholars disagree on its precise contours. The opera-tion and applicability of reciprocity frequently depend on the legal source ofthe obligation, the political standing of the actor to whom the obligation isowed, and subjective evaluations of the nature of the obligation itself. Thissection identifies two main types of reciprocity, obligational and observa-tional reciprocity, and discusses their operation and limitations in bothtreaty and customary international law. It concludes by distinguishing reci-procity from reprisal.

A. Reciprocity and Treaty Law

Generally speaking, the international law of treaties governs law of wartreaties. The law of treaties is a set of secondary rules—in other words,

REV. 161 (1960) (citing HOWARD BECKER, MAN IN RECIPROCITY (1956); L.T. HOBHOUSE, MORALS IN

EVOLUTION: A STUDY IN COMPARATIVE ETHICS (2d ed. 1951)).16. Keohane, supra note 14, at 4. R17. Id. at 14. R18. Id. at 4.19. Id. at 25.20. Id. at 27.



“rules about rules.”21 Secondary rules guide the application and interpreta-tion of primary rules that prescribe or describe lawful conduct. For instance,the Vienna Convention on Diplomatic Relations describes duties and obli-gations owed to states’ representatives by their foreign hosts.22 Primary rulesof the Convention include the inviolability of embassy premises,23 exemp-tion from taxes,24 and immunity from arrest for diplomatic agents.25 TheConvention also includes secondary rules which condition the operation ofprimary rules. For example, the Convention prohibits parties from discrimi-nating between states in their application of the Convention’s protections.26

Thus, like nearly all other primary international rules, the Convention’s pri-mary rules operate subject to the secondary rules of international law.

The principle of reciprocity has long been recognized as an importantsecondary rule under the law of treaties. Reciprocity places conditions on thebinding force, interpretation, and operation of treaties. As a general matter,rules of treaty interpretation have evolved from custom into a formal “treatyon treaties.”27 Detailed, codified rules, often tailored to specific types oftreaties and obligations, now guide states’ interpretation and implementa-tion of their treaty obligations. Prior to examining this evolution, however,it will be useful to outline some generally applicable doctrines associatedwith reciprocity.28

Understood broadly, reciprocity operates in both an obligational senseand an observational sense. Reciprocity operates on an obligational level inthat states are generally bound by treaties only in their relations with statesthat have consented to be bound by the same treaty.29 The binding effect ofa treaty is thus contingent on other states’ reciprocating with indicia of in-

21. See H.L.A. HART, THE CONCEPT OF LAW (1961). Hart perceived that secondary rules alleviateuncertainty, inalterability, and inefficiency in primary rules. Id. Hart noted, however, a dearth of maturesecondary rules in international law. Id. at 209.

22. Vienna Convention on Diplomatic Relations art. 22, opened for signature Apr. 18, 1961, 23 U.S.T.3227, 500 U.N.T.S. 95, T.I.A.S. No. 7502 [hereinafter Diplomatic Relations Convention].

23. Diplomatic Relations Convention, supra note 22, art. 22. R24. Id. art. 23.25. Id. art. 29.26. Id. art. 47. Article 47 conditions equal application of the Convention’s protections and immuni-

ties on reciprocity. Id. The article does not label as discriminatory situations “where the receiving Stateapplies any of the provisions of the present Convention restrictively because of a restrictive application ofthat provision to its mission in a sending State . . . .” Id. art. 47, ¶ 2.

27. Vienna Convention on the Law of Treaties arts. 11, 26, opened for signature May 23, 1969, 1155U.N.T.S. 331 (entered into force Jan. 27, 1980) [hereinafter Vienna Convention].

28. See generally LORD MCNAIR, THE LAW OF TREATIES (1961) (discussing early to mid-twentiethcentury law of treaties).

29. Vienna Convention, supra note 27, arts. 11, 26. The Vienna Convention supports the legal maxim Rpacta sunt servanda (agreements must be kept) in this regard.



tent to be bound.30 In this sense, the operation of treaties is contingent onobligational reciprocity.31

It is not surprising that legal scholars often analogize treaties to con-tracts.32 Indeed, many treaties refer to parties as “High Contracting Par-ties.”33 Lawyers and scholars trained in civil law systems occasionally citethe legal maxim inadimplenti non est adimplendum34 to describe the contract-like, reciprocity-based nature of treaty obligations.35 Similar to the law of

30. Most treaties require a minimum number of ratifications between any states parties prior to enter-ing into force. See, e.g., U.N. Charter art. 110, para. 3; General Agreement on Tariffs and Trade art. 26,opened for signature Oct. 30, 1947, 61 Stat. A-11, 55 U.N.T.S. 194; Geneva Convention Relative to theTreatment of Prisoners of War art. 92, Aug. 12, 1949, 6 U.S.T. 3316, 75 U.N.T.S. 135; InternationalCovenant on Civil and Political Rights art. 49, opened for signature Dec. 16, 1966, 933 U.N.T.S. 171;Vienna Convention, supra note 27, art. 84; Rome Statute of the International Criminal Court art. 126, RJuly 17, 1998, 2187 U.N.T.S. 90, 37 I.L.M. 1002.

31. Derek Jinks has referred to required mutuality of obligations as “first-order reciprocity.” DerekJinks, The Applicability of the Geneva Conventions to the “Global War on Terrorism,” 46 VA. J. INT’L L. 165,192 (2004). Realist international relations scholars addressing bilateral or “specific” reciprocity mini-mize the concept of obligation. Thus, Robert Keohane and Robert Axelrod argue that reciprocity may besatisfied through real time reactions to actual behavior rather than prescriptive obligations. Keohane,supra note 14, at 19–20 (remarking that Axelrod declines to address obligation in his theory of reciproc- Rity). In place of formal commitment and putatively binding agreements, Keohane and Axelrod envision agame of tit-for-tat on the basis of self-interest. Id. at 19. However, Keohane concedes a place for obliga-tion in multilateral settings. As mentioned, he offers the term “diffuse reciprocity” to describe situationswhere one’s counterpart is a group rather than an individual actor. See supra text accompanying notes18–20. Especially in sociological and anthropological literature, “the language of reciprocity is the lan-guage of obligation.” Id. at 20–21 (citing BARRINGTON MOORE, JR., INJUSTICE: THE SOCIAL BASES OF

OBEDIENCE AND REVOLT 506 (1978); Alvin W. Gouldner, The Norm of Reciprocity: A Preliminary State-ment, 25 AM. SOC. REV. 161, 169–71 (1960)).

32. MALCOLM N. SHAW, INTERNATIONAL LAW 88–89 (5th ed. 2003); SHABTAI ROSENNE, THE LAW

OF TREATIES 46 (1970) (equating the law of treaties, the law of contract, and the civil law notion of “thelaw of obligations”); 1 HERSCH LAUTERPACHT, INTERNATIONAL LAW 351 (1970) (observing that “thecontractual nature of all treaties is now no longer seriously challenged”).

33. See, e.g., Geneva Conventions, infra note 155; Hague Convention IV (pmbl.), infra note 179. RHague Convention IV also uses the term “Contracting Powers” in Article 1. The Vienna Conventionmay have altered the term’s legal significance. See Vienna Convention, supra note 27. The Vienna Con- Rvention defines “contracting state” as one that has consented to be bound prior to a treaty’s entry intoforce. Id. art. 2. The Convention uses the term “party” following entry into force. Id. Some later treatiesemploy “States Parties.” See also Rome Statute of the International Criminal Court art. 2, July 17, 1998,2187 U.N.T.S. 90, 37 I.L.M. 1002; Convention on the Prohibition of the Development, Production, andStockpiling of Bacteriological (Biological) and Toxin Weapons and Their Destruction art. 10, Apr. 10,1972, 1015 U.N.T.S. 163, 11 I.L.M. 309. But see Protocal Additional to the Geneva Conventions of 12August 1949, and Relating to the Protection of Victims of Interntional Armed Conflicts (Protocol I) art.1, Dec. 7, 1979, 1125 U.N.T.S. 3 (continuing to use the term “High Contracting Parties”).

34. If one party violates a treaty obligation, the other party can refuse to perform the correspondingobligation. Specifically, “[a] state’s compliance with the rules hinges on another state’s observance; in-adimplenti non est adimplendum.” ZOLLER, supra note 9, at 15; see also John Norton Moore, Enhancing RCompliance with International Law: A Neglected Remedy, 39 VA. J. INT’L L. 881, 957–62 (1999) (explainingthe right to refuse reciprocal performance if a treaty obligation is violated by the other party); OscarSchachter, In Defense of International Rules on the Use of Force, 53 U. CHI. L. REV. 113 (1986) (discussingthe use of armed force as a reaction to the violation of international law).

35. See, e.g., Prosecutor v. Kupreskic, Case No. IT-95-16-T, Judgment, ¶ 520 (Jan. 14, 2000). TheInternational Criminal Tribunal for Yugoslavia observed:

[A] material breach of that treaty obligation by one of the parties would not entitle the otherto invoke that breach in order to terminate or suspend the operation of the treaty. Article 60(5)provides that such reciprocity or in other words the principle inadimplenti non est adimplendum



contracts, treaty law requires evidence of parties’ intent to be bound.36 Likecontracts, treaties traditionally do not create obligations or rights for thirdparties.37

The decision of the International Court of Justice (“ICJ”) in the seminalNorth Sea Continental Shelf cases illustrates how the requirement of mutualconsent limits treaty obligation.38 These cases arose from a dispute over aterritorial boundary in the shallow waters between West Germany, on theone hand, and Denmark and the Netherlands on the other. Denmark and theNetherlands promoted a provision of the 1958 Geneva Convention on theContinental Shelf as the proper basis for the Court’s decision.39 They arguedthat West German public statements in support of the Convention weresufficient indicia of West Germany’s consent to be bound.40 The ICJ re-jected application of the provision in question, and the treaty generally, be-cause West Germany had not ratified the Convention.41 The Court insistedthat treaty obligations do not arise casually, particularly when legal instru-ments specify formal means of manifesting intent to be bound.42 The Courtfound the dangers of applying conventional provisions absent clear manifes-tations of consent so obvious as to be “hardly worth stressing.”43

does not apply to the provision relating to the protection of the human person contained intreaties of humanitarian character, in particular the provisions prohibiting any form of reprisalagainst persons protected by such treaties.

Id.36. Vienna Convention, supra note 27, art. 11. Article 11 includes signature, exchange of instruments, R

ratification, acceptance, approval, or accession as means for expressing a state’s intent to be bound by atreaty. Id.

Additionally, Article 11 requires evidence of intent to be bound by a treaty, but it can sometimes bedifficult to interpret expressions of intent. States will need to look at many factors in the treaty negotia-tion process. See Jerry Z. Li, The Legal Status of Three Sino-U.S. Joint Communiques, 5 CHINESE J. INT’L L.617, 624–25 (Nov. 2006).

37. Vienna Convention, supra note 27, art. 34. The Convention outlines exceptions to the general Rrule, primarily where third parties express consent. Id. arts. 35–36. The similarities between contractsand treaties offer an opportunity to compare third-party rights and obligations. In both contracts andtreaties, a third party does not have rights unless the parties intended to create rights for the third party.Just as courts interpreting contracts look outside the document itself to ascertain the parties’ intent, theinterpretation of treaties can expand to include sources other than the treaty itself; for instance, previousdrafts and preparatory works can indicate an intent to create third-party rights and obligations. See, e.g.,Sital Kalantry, The Intent-to-Benefit: Individually Enforceable Rights Under International Treaties, 44 STAN. J.INT’L L. 63, 74–83 (2008).

Nonetheless, third parties are quite often affected by treaties other states make. See, e.g., Gabriella Blum,Bilateralism, Multilateralism, and the Architecture of International Law, 49 HARV. INT’L L. J. 323, 361(2008).

38. North Sea Continental Shelf Cases (F.R.G. v. Den., F.R.G. v. Neth.), Advisory Opinions andOrders, 1969 I.C.J. 3 (Feb. 20, 1969) [hereinafter North Sea Continental Shelf Cases].

39. Id. ¶ 25. The parties did not call upon the Court to demarcate the border, but merely asked toidentify the relevant international legal rule. Id.

40. Id.41. Id. ¶ 27.42. Id. ¶ 28.43. Id. ¶ 33.



The practice of submitting reservations to treaties also illustrates the op-eration of obligational reciprocity. As a general matter, states need not ac-cept treaties wholesale.44 The law of treaties permits states to conditionratification on exclusion of particular treaty provisions.45 Once submitted, astate’s treaty reservation stands for acceptance or rejection by the treaty’sremaining states parties on an individual basis.46 If accepted by another stateparty, the reservation modifies the agreement between the reserving andaccepting state to the extent of the reservation.47 If the reservation is re-jected, the entire provision in question does not operate between the twostates. Thus, the practice of reservations closely observes the principle ofobligational reciprocity. It also illustrates the existence of bilateral interac-tions within multilateral treaty systems.48

Obligational reciprocity operates in emerging forms of international legalobligations as well as treaties. International law increasingly recognizes arole for quasi-contractual instruments that do not rise to the level of treaties.States and international law scholars have distinguished this so-called “softlaw” from binding treaties and customs. It often takes the form of nonbind-

44. Vienna Convention, supra note 27, art. 19. R45. Id. Reservations that operate contrary to the “object and purpose” of treaties are generally forbid-

den. Id. art. 19(b). Furthermore, some treaties expressly forbid reservations or limit the subject of permis-sible reservations. For instance, the 1993 Chemical Weapons Convention prohibits any reservations tothe provisions of the Convention, permitting reservations only to the Convention’s Annex. Conventionon the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and onTheir Destruction art. 12, opened for signature Jan. 13, 1993, 1974 U.N.T.S. 45, S. Treaty Doc. No.103–21 (1993). Other treaties appear to limit reservations through more subtle textual schemes. TheConvention against Torture addresses reservations in three substantive articles, suggesting that statesmay not submit reservations to articles that do not include an explicit reservation provision. Conventionagainst Torture and other Cruel, Inhuman or Degrading Treatment or Punishment arts. 28–30, opened forsignature Dec. 10, 1984, 1465 U.N.T.S. 8. The U.N. Human Rights Committee has gone further withrespect to human rights instruments. In its General Comment 24, the Committee observed, “Althoughtreaties that are mere exchanges of obligations between States allow them to reserve inter se application ofrules of general international law, it is otherwise in human rights treaties, which are for the benefit ofpersons within their jurisdiction.” Off. of High Comm’r for Hum. Rts. [OHCHR], General Comment No.24: Issues relating to reservations made upon ratification or accession to the Covenant or the Optional Protocolsthereto, or in relation to declarations under article 41 of the Covenant, CCPR/C/21/Rev.1/Add.6 (Apr. 11,1994), available at http://www.unhchr.ch/tbs/doc.nsf/0/69c55b086f72957ec12563ed004ecf7a?Opendocument.

46. Former practice had required unanimous state party acceptance of treaty reservations. D.W.Greig, Reciprocity, Proportionality, and the Law of Treaties, 34 VA. J. INT’L L. 295, 327 (1994). The individ-ual system of accepting or rejecting reservations emerged after recognition of impracticalities of theformer system in multilateral treaties. Id. (citing Reservations to the Convention on Prevention andPunishment of the Crime of Genocide, Advisory Opinion, 1951 I.C.J. 15, 21–22 (May 28)).

47. Vienna Convention, supra note 27, art. 21. R48. The International Court of Justice confirmed the contractual nature of the treaty reservation sys-

tem in the 1951 Advisory Opinion on Reservations to the Genocide Convention, supra note 46. The RCourt observed that “no reservation was valid unless it was accepted by all the contracting parties.” Id. at6. Commentators have minimized the legal effect of the Court’s conclusion, noting that the Court merelyaddressed reservations to the Convention as positive law, leaving unaddressed the mitigating effect oftreaty provisions that have attained customary status. See MARK VILLIGER, CUSTOMARY INTERNATIONAL

LAW AND TREATIES 260 (1985).



ing resolutions issued by international organizations or governing bodies49

but may also arise from agreements between states.50 Although soft law is anincreasingly prevalent and influential form of obligation,51 it falls short ofinternational law in the formal sense. Furthermore, obligational reciprocityoften conditions the binding force of states’ duties.52

Reciprocity doctrine traditionally operates at an observational level aswell as an obligational level. Once the parties bind themselves, the contin-ued force of a treaty is contingent on reciprocal observation by states par-ties.53 That is, states are bound by a treaty only to the extent that otherstates observe the treaty’s substantive provisions in practice. Material breachof a treaty is widely accepted as a sufficient cause for an affected party toterminate or suspend operation of the provision at issue or, in extreme cases,the entire treaty.54 In an effort to refine the doctrine of reciprocity, interna-

49. The U.N. General Assembly issues resolutions at nearly every session. See, e.g., G.A. Res. 50/1,U.N. Doc. A/RES/50/1 (Oct. 19, 1995); 1978 U.N.E.P. Draft Principles of Conduct in the Field of theEnvironment for the Guidance of States in the Conservation and Harmonious Utilization of NaturalResources Shared by Two or More States, reprinted in 17 I.L.M. 1094, 1097 (1978).

50. Conference on Security and Co-operation in Europe: Final Act, Aug. 1, 1975, 14 I.L.M. 1292.51. Soft law regulations are occurring with more frequency. Williamson observes:

Diplomats and their governments sometimes prefer concluding soft law instruments becausedoing so can be easier than adopting treaties. Soft law instruments are advantageous becausethey avoid constitutional and other domestic legal requirements in most democracies for entryinto force that apply to treaties. Another commonly cited advantage is the very fact that softlaw is nonbinding, making it easier to induce a reluctant state to become a party, and over-coming a state’s fears that it might be committing itself to a course of conduct when futurecircumstances are hard to foresee.

Richard L. Williamson, Jr., Hard Law, Soft Law, and Non-Law in Multilateral Arms Control: Some Compli-ance Hypotheses, 4 CHI. J. INT’L L. 59, 63 (2003); see also Christopher C. Joyner, Recommended MeasuresUnder the Antarctic Treaty: Hardening Compliance with Soft International Law, 19 MICH. J. INT’L L. 401(1998) (detailing the adoption of certain recommendations and behavior-regulating measures as soft lawwithin the Antarctic Treaty System).

52. “As soft law, Antarctic Treaty recommendations carry a certain measure of legal authority. Con-sultative Parties hold strong expectations that norms contained in adopted recommendations will com-mand respect by all ATCP governments, as well as by other Antarctic Treaty Parties, and that thesenorms will be adhered to over the long term.” Joyner, supra note 51, at 414. R

53. LORD MCNAIR, THE LAW OF TREATIES 573 (1961). Lord McNair observes, “[I]t is not uncommonfor the injured state, by way of sanction, to suspend the operation of a provision corresponding to, oranalogous with, the provision broken.” Id. However, he further notes the uncertain and then-largelyuncodified status of his rule. Id. The U.S. Supreme Court has confirmed the general rule of suspension inresponse to breach. Justice Iredell observed, “It is part of the law of nations, that if a treaty be violated byone party, it is at the option of the other party, if innocent, to declare, in consequence of the breach, thatthe treaty is void.” Ware v. Hylton, 3 U.S. 199, 261 (1796). In 1986, in response to New Zealand’srefusal to grant reciprocal access to ports and air strips, the United States suspended observance of itssecurity obligations toward New Zealand under the 1951 ANZUS Pact. See OFFICE OF THE LEGAL AD-

VISER, DEP’T OF STATE, 1 CUMULATIVE DIGEST OF UNITED STATES PRACTICE IN INTERNATIONAL LAW

1981–88 (Marian Nash (Leich) ed., 1993) (citing Australia, New Zealand, United States Security Treaty(ANZUS Pact), Sep. 1, 1951, 3 U.S.T. 3420, T.I.A.S. 2493).

54. Vienna Convention, supra note 27, art. 60. The Convention describes a material breach as either Rrepudiation of the treaty or “violation of a provision essential to the accomplishment of the object orpurpose of the treaty.” Id. art. 60, ¶ 3(a) & (b). But see Herbert W. Briggs, Unilateral Denunciation ofTreaties: The Vienna Convention and the International Court of Justice, 68 AM. J. INT’L L. 51 (1974). Com-menting on the ICJ’s 1971 Namibia advisory opinion, Briggs laments what he considers Court dictum,



tional lawyers have identified two strains of observational reciprocity in statepractice and treaty law: “positive” and “negative” reciprocity.

Negative reciprocity, perhaps the more intuitive strain, refers to state sus-pensions of legal obligations in response to breaches.55 The 1969 ViennaConvention on the Law of Treaties codified much of the traditional law oftreaties.56 It outlines a range of options for the exercise of negative reciproc-ity, drawing a clear distinction between bilateral and multilateral treaties.The Convention subjects bilateral treaties to less stringent limitations on theexercise of negative reciprocity by permitting suspension or termination atthe discretion of the non-breaching party.57

In the case of material breach of a multilateral treaty, non-breaching par-ties have four options. First, with the unanimous agreement of the treatyparties, they may terminate the treaty in whole or in relevant part in theirmutual relations with the breaching state.58 Second, subject again to unani-mous agreement, the parties may terminate the treaty as between all theparties, essentially dissolving the agreement altogether.59 Third, states thathave been specially affected by the breach may unilaterally suspend thetreaty in their relations with the breaching state.60 Finally, any party otherthan the breaching state may suspend the treaty when the breach “radicallychanges” the parties’ positions with respect to future performance.61

recognizing a general right to terminate treaties in response to breach. Id. at 55. Briggs asserts, “TheCourt produces no evidence to support its allegation that a general principle of law establishes ‘a right oftermination on account of breach.’” Id.

Prior to the Vienna Convention, international tribunals addressed the general principle of reciprocityon at least two occasions. In the Diversion of Water from Meuse case at the Permanent Court of InternationalJustice, Belgium claimed suspension of a provision of the Treaty of 1863 by virtue of Dutch breach.Diversion of Water from Meuse (Neth. v. Belg.), 1937 P.C.I.J. (ser. A/B) No. 70, at 7 (June 28). Whilethe Court held that the Netherlands had not breached the treaty, a dissenting opinion observed that theprinciple of inadimplenti non est adimplentum was “so just, so equitable, so universally recognized that itmust be applied in international relations also.” Id. (Judge Anzilotti dissenting). In the Tacna-AricaArbitration, an arbitrator evaluated a Peruvian claim of discharge from obligations under the Treaty ofAncon because of Chilean breach. 2 REPORTS OF INTERNATIONAL ARBITRAL AWARDS 929, 943–44. Thearbitrator confirmed the general remedy of termination of the treaty in the face of breach. Id. However,he limited the practice to occasions of “fundamental” breach. International Law Commission, Report onits 18th Sess. (1966), U.N. GAOR, 21st Sess., U.N. Doc. A/6309/Rev. 1 (Jan. 3–28, 1966), reprinted in61 AM. J. INT’L L. 248, 423 (1967).

55. See FRITS KALSHOVEN & LIESBETH ZEGVELD, CONSTRAINTS ON THE WAGING OF WAR 143 (3d ed.2001); GEORG SCHWARZENBERGER, 2 INTERNATIONAL LAW AS APPLIED BY INTERNATIONAL COURTS

AND TRIBUNALS: THE LAW OF ARMED CONFLICT 453 (1968) (noting that belligerents may use reprisalsto “reverse the operation of the chief working principle behind the laws of war from positive, to negative,reciprocity”).

56. See Legal Consequences for States of the Continued Presence of South Africa in Namibia (SouthWest Africa) notwithstanding Security Council Resolution 276, Advisory Opinion, 1971 I.C.J. 16, ¶ 94(June 21) [hereinafter I.C.J. Namibia Advisory Opinion].

57. Vienna Convention, supra note 27, art. 60, ¶ 1. R58. Id. art. 60, ¶ 2(a)(i).59. Id. art. 60, ¶ 2(a)(ii).60. Id. art. 60, ¶ 2(b).61. Id. art. 60, ¶ 2(c).



The Vienna Convention enjoys wide ratification.62 In addition to bindingstates parties, the Convention’s reciprocity regime likely binds non-parties63

as a matter of customary international law.64 The Commentary to an earlierdraft convention indicates that the majority of contemporary jurists re-garded the statements on reciprocity contained in paragraphs one throughthree of Article 60 as reflective of customary rules.65 Preparatory works onnegative reciprocity had attempted to divest states of unilateral authority tosuspend treaty provisions in case of breach.66 A draft convention on treatylaw devised a procedure whereby suspensions in response to breach would beprovisional only, requiring confirmation by an international tribunal to havepermanent effect.67 However, states—rejecting such limits—ultimately re-tained unilateral authority to exercise negative reciprocity under the ViennaConvention.

Positive reciprocity is the second strain of obligational reciprocity. It re-fers to states’ efforts to induce reciprocal compliance from other actorsthrough continued respect for an international norm or treaty provision,notwithstanding their legal right not to comply by virtue of breach or non-

62. Forty-five states are signatories to the Treaty, and 108 states are currently parties to it. UnitedNations Treaty Collection, http://treaties.un.org (last visited Mar. 10, 2009).

63. Although the United States is not a party to the Vienna Convention, U.S. courts have recognizedthe Vienna Convention as codification of customary international law. See Chubb & Son, Inc. v. AsianaAirlines, Inc., 214 F.3d 301, 308 (2d Cir. 2000). Additionally, the international legal community hasrecognized the customary status of the Vienna Convention:

[A]ccording to a widespread opinio juris, legal conviction of the international community, theVienna Convention represents a treaty which to a large degree is a restatement of customaryrules, binding states regardless of whether they are parties to the Convention. Even before theConvention entered into force, its provisions had been invoked by states and by the Interna-tional Court of Justice.

Maria Frankowska, The Vienna Convention on the Law of Treaties Before United States Courts, 28 VA. J. INT’LL. 281, 286 (1988) (citing Fisheries Jurisdiction (U.K. v. Ice.), 1973 I.C.J. 3 (Feb. 2)); see also AppealRelating to the Jurisdiction of the ICAO Council (India v. Pak.), 1972 I.C.J. 46 (Aug. 18)); I.C.J.Namibia Advisory Opinion, supra note 56. R

64. See infra text accompanying notes 71–74 (outlining customary international law generally). R65. See International Law Commission, supra note 54. A later section of this article discusses the R

customary status of article 60, paragraph 5. See infra Part IV. The International Law Commission draftcited herein did not include the provision that became paragraph 5 in the final version of the ViennaConvention.

66. The Vienna Convention’s rules on reciprocity replicate to some extent preparatory work of theHarvard Research in International Law project. Conducted between 1932 and 1935, the project produceda Draft Convention on the Law of Treaties as part of its comprehensive, multi-volume survey of Interna-tional Law. Draft Convention on the Law of Treaties, in 29 AM. J. INT’L L. SUPP. (1935), reprinted in 2THE HARVARD RESEARCH IN INTERNATIONAL LAW: ORIGINAL MATERIALS 1077 (John P. Grant & J.Craig Barker eds., 2008) [hereinafter HARVARD RESEARCH COMMENTARY]. Article 27 of the Draft Con-vention recognizes suspension of a treaty obligation as a legitimate response to breach. Id. The DraftConvention, however, requires consultation or authority from “a competent international tribunal” priorto declaring that the treaty itself is no longer binding. Id. The researchers were concerned that statesought not “be the final judges in their own causes by permitting them unilaterally to terminate thetreaty as between themselves and the party or parties alleged to have violated the treaty.” Id. Article 60of the Vienna Convention reveals that states chose not to adopt the consultation requirement. ViennaConvention, supra note 27, art. 60. R

67. HARVARD RESEARCH COMMENTARY, supra note 66, at 1077. R



accession by other states.68 For example, a number of treaties include offersto non-state parties to comply on an ad hoc basis or to express their intent toobserve the instrument’s primary rules.69 In exchange, state parties agree toreciprocate. Although positive reciprocity represents a more hopeful strain ofthe doctrine, it is not an obligation under general international law. Its op-eration is usually restricted to treaties bearing such express provisions oroffers made as a matter of state policy rather than law.70

The previous discussion demonstrates that states have developed and evencodified highly refined secondary rules for treaty interpretation and applica-tion. These rules account for both obligational and observational compo-nents of reciprocity in treaty practice. The following section discusses theextent to which these rules operate in the separate realm of customary inter-national law.

B. Reciprocity and Customary International Law

While treaty law is often cited as the chief source of modern internationallegal obligations,71 it by no means represents the full extent of internationalconstraints on states’ conduct. In fact, in a hierarchy of international law,some commentators would give primacy to custom.72 According to a widelyaccepted formula, customary international law is general and consistent statepractice exercised out of a sense of legal obligation.73 As conflicting case lawand scholarship attests, however, the formula is much more easily statedthan applied.74 The ambiguous nature and content of customary interna-tional law complicates its relationship with the principle of reciprocity. Thissection demonstrates that reciprocity operates slightly differently in the

68. KALSHOVEN & ZEGVELD, supra note 55, at 143. Article 2 of the 1949 Geneva Conventions antici- Rpates positive reciprocity.

69. Geneva Convention Relative to the Treatment of Prisoners of War, Aug. 12, 1949, 6 U.S.T.3316, 75 U.N.T.S. 135; European Convention for the Protection of Human Rights and FundamentalFreedoms, Nov. 4, 1950, E.T.S. No. 50, 213 U.N.T.S. 222; Universal Declaration of Human Rights,G.A. Res. 217A, at 71, U.N. GAOR, 3d Sess., 1st plen. mtg., U.N. Doc. A/810 (Dec. 12, 1948).

70. The Vienna Convention reflects no agreement between states on positive reciprocity evidentlyreserving the issue for resolution on a treaty-by-treaty basis. See Vienna Convention, supra note 27. R

71. Maria Frankowska, The Vienna Convention on the Law of Treaties Before United States Courts, 28 VA. J.INT’L L. 281, 285 (1988) (stating that “treaties, ‘the cement that holds the world community together’are today the primary source of international obligations”). But see THEODOR MERON, THE HUMANIZA-

TION OF INTERNATIONAL LAW 360 (2006) (noting that customary law has regained ground since 1970s);ANTHONY A. D’AMATO, THE CONCEPT OF CUSTOM IN INTERNATIONAL LAW 12 (1971) (arguing thatcustom enjoys a more responsive process of development and broader scope of application than treatylaw).

72. DAVID J. BEDERMAN, INTERNATIONAL LAW FRAMEWORKS 15 (2001); D’AMATO, supra note 71, at R12.

73. RESTATEMENT (THIRD) OF FOREIGN RELATIONS LAW OF THE UNITED STATES § 102 (1987). Simi-larly, the Statute of the International Court of Justice defines customary law as “evidence of generalpractice accepted as law.” Statute of the International Court of Justice art. 38, ¶ 1(b), June 26, 1945, 59Stat. 1055, 33 U.N.T.S. 993.

74. See BARRY E. CARTER & PHILLIP R. TRIMBLE, INTERNATIONAL LAW 134–35 (3d ed. 1999) (citingJ. STARKE, INTRODUCTION TO INTERNATIONAL LAW 34–38 (9th ed. 1984) and other scholarship investi-gating formation of customary international law).



realm of customary international law than in treaty law because custom doesnot require the consent of the parties to be binding. As a result, observa-tional reciprocity is much more salient in this area than obligationalreciprocity.

Customary law supplements and interacts with treaty law in a complexmanner.75 International norms and rules often migrate between custom andtreaty.76 Treaty conferences not only create new law but also codify existingcustomary rules into the less ambiguous form of treaties. Similarly, provi-sions of widely-ratified and effective treaties often mature into customaryrules that bind all states regardless of their individual ratification status.

For instance, custom played a decisive role in the North Sea ContinentalShelf cases addressed above. While the ICJ summarily dismissed the conten-tion that the Continental Shelf Convention bound West Germany as a non-party, the Court entertained far more seriously the Danish and Dutch posi-tion that the Convention’s provisions reflected preexisting customary inter-national law.77 Ultimately, the Court found the evidence inadequate tosupport the argument that the Convention had merely codified preexistingcustomary rules concerning the demarcation of international nautical bound-aries.78 Instead, the Court determined that the rule supporting the Danishand Dutch stance was “a purely conventional rule.”79 The Court also re-jected the assertion that the Convention had matured into customary lawafter its entry into force. However, it conceded the principle behind theDanish and Dutch argument by noting that treaties can create bindingnorms if their provisions mature into custom. But the Court established ahigh burden of proof on parties seeking to give treaty provisions the excep-tional effect of binding states that had not ratified them.80 In a similar vein,

75. See MARK E. VILLIGER, CUSTOMARY INTERNATIONAL LAW AND TREATIES 122–30, 255–78 (1985)(discussing and contrasting the jus scriptum and custom, as well as explaining their very complexinteractions).

76. Id. at 156–67, 237–49.77. North Sea Continental Shelf Cases, supra note 38, ¶¶ 47–56, 60–68 (surveying state practice, R

opinions of international law experts and commissions, and decisions for indicia of the inherency orcustomary status of the equidistance rule).

78. Id. ¶ 69.79. Id. ¶ 74.80. Id. ¶¶ 71–74. The U.S. Supreme Court announced a similarly high standard of proof for the

existence of customary norms in Sosa v. Alvarez-Machain, 542 U.S. 692, 733–34 (2004). The Courtresorted to its own longstanding standard for identifying customary international law, observing:

[C]laim[s] must be gauged against the current state of international law, looking to thosesources we have long, albeit cautiously, recognized. “Where there is no treaty, and no control-ling executive or legislative act or judicial decision, resort must be had to the customs andusages of civilized nations; and, as evidence of these, to the works of jurists and commentators,who by years of labor, research and experience, have made themselves peculiarly well ac-quainted with the subjects of which they treat. Such works are resorted to by judicial tribu-nals, not for the speculations of their authors concerning what the law ought to be, but fortrustworthy evidence of what the law really is.”

Id. (quoting The Paquete Habana, 175 U.S. 677, 700 (1900)).



Theodor Meron has identified examples of custom operating as a legal back-stop where failures of reciprocity prevented treaties from operating.81

Early twentieth century scholarship suggested that the doctrine of reci-procity applied with equal force to both customary and treaty law.82 Lack ofreciprocal obligation or observance gave rise to rights of suspension of cus-tomary law.83 However, current scholarship suggests that reciprocity mightoperate differently in the realm of custom.84 At a minimum, this is likelytrue for obligational reciprocity. By definition, established customary normsbind states regardless of formal or express indicia of consent such as ratifica-tion.85 Customary law reaches all states by virtue of their claims to sovereignstatus. Thus observance of customary norms is not subject to the conditionof express reciprocal commitment from other states. Yet in the long term,repeated and especially widespread disregard or suspension of a rule of cus-tomary law would certainly undermine the element of state practice requiredfor the rule to sustain its binding force.

Custom may not be an effective check on the operation of reciprocity ininternational law. Customary international law recognizes the status of per-sistent objector,86 which refers to states that consistently and expressly pur-

81. Theodor Meron, The Continuing Role of Custom in the Formation of International Humanitarian Law,90 AM. J. INT’L L. 238, 239 (1996). Meron cites failure of the 1907 Hague Regulations and the 1929Geneva Convention during the Second World War as the basis for the International Military Tribunal’sand the U.S. Nuremberg Military Tribunal’s resort to custom. Id. (citing TRIAL OF MAJOR WAR

CRIMINALS, 1946, CMD. 6964, Misc. No. 12, at 65; 11 TRIALS OF WAR CRIMINALS BEFORE THE NUREM-

BERG MILITARY TRIBUNALS UNDER CONTROL COUNCIL LAW No. 10, at 462, 533–35 (1948)). Meron alsonotes the International Court of Justice’s resort to custom to decide the Paramilitary Case between theUnited States and Nicaragua. Id. (citing Military and Paramilitary Activities in and against Nicaragua(Nicar. v. U.S.), Merits, 1986 I.C.J. 14, 114, ¶¶ 218–20 (June 27)).

82. KALSHOVEN, supra note 9, at 24 (citing LE FUR, supra note 9). Le Fur contended that the doctrine Rof reciprocity applied equally to conventional and customary law. He observed that “[r]eciprocity isfundamental to a system of conventions between equals.” Without reciprocity, concluded Le Fur, “inter-national law would work toward its own destruction.” Id. at 24 (translated by Kalshoven).

83. ZOLLER, supra note 9, at 15. R84. MARK E. VILLIGER, CUSTOMARY INTERNATIONAL LAW AND TREATIES 274–75 (1985). Villiger

contends that Article 60(5) operates with respect to both conventional and customary norms. Id. TheInternational Law Commission has observed that the maxim inadimplenti non est adimplendum “was not aprinciple that applied to international law in general and was apparently not applicable in the context ofcustomary law.” Summary Records of the 2590th Meeting, [1999] 1 Y.B. Int’l L. Comm’n 165, U.N. Doc.A/CN.4/SER.A./1999.

85. Although the formation of custom requires “general” practice, unanimous or universal practice oraccession is not required to establish general obligation. See 1 HERSCH LAUTERPACHT, INTERNATIONAL

LAW: COLLECTED PAPERS 68 (Elihu Lauterpacht ed., 1970). Lawyers in the U.S. Department of JusticeOffice of Legal Counsel expressed a skeptical view of the legal status of customary law, in part because itwas not based on the express consent of states. Memorandum for William J. Haynes II, Gen. Counsel,Dep’t of Defense, Application of Treaties and Laws to al Qaeda and Taliban Detainees (Jan. 9, 2002)reprinted in THE TORTURE PAPERS, supra note 8, at 38, 72. R

86. See RESTATEMENT (THIRD) OF FOREIGN RELATIONS LAW OF THE UNITED STATES §102, cmt. d(1987) [hereinafter RESTATEMENT (THIRD) OF FOREIGN RELATIONS]. Some writers express less enthusias-tic support for the doctrine of persistent objection. See SHAW, supra note 32, at 86. Shaw limits the Rdoctrine to states that have objected since the origin of the custom in question.



port to opt out of particular customary norms.87 While some customarynorms may not be subject to persistent objection, many can be avoided byrigorous exercise of objections.88 It is foreseeable that states bound by a cus-tomary norm would decline to apply that norm to persistent objectors onthe basis of lack of reciprocal obligation. Thus persistent objection may bean exception to custom’s non-requirement of express obligationalreciprocity.

For instance, suppose that in the North Sea Continental Shelf cases Germanyhad conceded the customary status of the Continental Shelf Convention pro-vision in question. Imagine that Denmark had persistently objected to therule. Germany might then have argued effectively for an exercise of negativereciprocity with respect to this customary norm, at least vis-a-vis Denmark.Germany could have claimed that though it was bound to respect non-ob-jecting states’ boundaries with regard to the norm, Germany did not owesuch respect to Denmark for its claim to exceptional excusal from the rule.No authoritative source resolves the scenario, yet the logic of obligationalreciprocity appears apposite.

Although the United States is not a party to the 1977 Additional Proto-cols to the Geneva Conventions, it has supported portions of the Protocols asreflective of customary international law.89 For instance, the United Stateshas indicated that the Protocol I provisions on medical transportation ofwounded, including the requirement that aircraft land for inspection whensummoned in contested territory, reflect custom. Yet the United Statesmakes clear that a summons to land need only be respected as a customaryrule where “there is a reasonable basis to believe the party ordering thelanding will respect the Geneva Conventions” or where the opposing forceconcludes an agreement to honor the rule in question itself.90 Thus recipro-cal commitment to the law of war conditions the United States’ obligationto respect this customary norm.

In the context of customary international law, states insist less on obliga-tional reciprocity than observational reciprocity—that is, reciprocal practice.As demonstrated previously with respect to treaty-based norms,91 some cus-

87. Ted Stein, The Approach of the Different Drummer: The Principle of the Persistent Objector in InternationalLaw, 26 HARV. INT’L L.J. 457 (1985).

88. IAN BROWNLIE, PRINCIPLES OF PUBLIC INTERNATIONAL LAW 11 (5th ed. 1998); Jonathan I. Char-ney, The Persistent Objector Rule and the Development of Customary International Law, 56 BRIT. Y.B. INT’L L.1, 16 (1985). Other writers have offered criticism of the persistent objector doctrine. See Andrew T.Guzman, Saving Customary International Law, 27 MICH. J. INT’L L. 115, 166 (2005); Holning Lau, Re-thinking the Persistent Objector Doctrine in International Human Rights Law, 6 CHI. J. INT’L L. 495 (2005).

89. See 1977 Protocols Additional to the Geneva Conventions: Memorandum for Mr. John H. Mc-Neill, Assistant Gen. Counsel, Office of the Sec’y of Def., Customary International Law Implication (May9, 1986) reprinted in THE JUDGE ADVOCATE GENERAL’S LEGAL CENTER & SCHOOL, LAW OF WAR DOCU-

MENTARY SUPPLEMENT 388, 389 (Sean Watts ed., 2006); Michael J. Matheson, Remarks in Session One: TheUnited States Position on the Relation of Customary International Law to the 1977 Protocols Additional to the1949 Geneva Convention, 2 AM. U. J. INT’L L. & POL. 419, 425 (1987).

90. Id.91. See supra text accompanying notes 66–68. R



tomary norms enjoy a degree of insulation from negative reciprocity. Per-emptory norms, or so-called jus cogens, describe a body of law widelyaccepted as binding all states in all situations.92 Like custom, jus cogens doesnot require express consent. Jus cogens is not susceptible to derogation orpreemption by treaty.93 Even adherents to the doctrine of persistent objec-tion usually concede that states may not opt out of jus cogens norms.94 In fact,exemption from persistent objection may be a hallmark of jus cogens, distin-guishing it from ordinary customary international law. That distinction it-self, however, lends a degree of credibility to claims that negative reciprocityremains available to states with respect to ordinary customary norms.

C. Reprisal Distinguished

The practice of reprisal has also evolved from a fundamental and nearlyuniversally recognized aspect of international law into a complex and con-tentious sanction. While reprisal’s application in the evolving internationallegal system is disputed, there is consensus on some limiting principles.

First, reprisals are reactive sanctions. Defined simply, reprisals are viola-tions of international law undertaken in response to unauthorized violationsby another subject of international law.95 Breach of a binding rule is anabsolute prerequisite to legitimate reprisal under nearly all conceptions ofthe practice.96 Reprisal also requires a degree of privity between parties.Generally, legitimate reprisals must be in response to breaches which haveadversely affected the state in question.97 Accordingly, no authority recog-nizes a right to anticipatory reprisal.

A second prerequisite for the exercise of reprisals is international legalpersonality.98 Only entities authorized to act within the international legal

92. See RESTATEMENT (THIRD) OF FOREIGN RELATIONS, supra note 86, cmt. k; United States v. Matta- RBallesteros, 71 F.3d 754, 764 (9th Cir. 1995).

93. See RESTATEMENT (THIRD) OF FOREIGN RELATIONS, supra note 86, cmt. k. Widely recognized jus Rcogens norms include rules against piracy, slavery, torture, and genocide. Id; see also Andrea Bianchi,Human Rights and the Magic of Jus Cogens, 19 EUR. J. INT’L L. 491 (2008).

94. Brad R. Roth, Abusive Treatment and the Limits of International Criminal Justice, 6 J. INT’L CRIM.JUST. 215, 224 (2008) (characterizing jus cogens norms as “all-purpose trumps” immune to persistentobjection).

95. Naulilaa Case, 2 R.I.A.A., 1011 (1928), reprinted in WHITEMAN, DIGEST OF INTERNATIONAL LAW

148–49 (1963). The case, heard by an international arbitration tribunal established by the VersaillesTreaty, addressed a German raid on Portuguese South-West Africa in retaliation for the death of threeGerman citizens. “The sine qua non of a legitimate resort to reprisals is that there should have been aprevious violation of international law by the other party . . . .” Id. The tribunal rejected Germany’sclaim to a legitimate right of reprisal, finding that Portugal had not engaged in any prior breach ofinternational law but had rather killed the German citizens by accident. Id.

96. Id.; Shane Darcy, The Evolution of the Law of Belligerent Reprisals, 175 MIL. L. REV. 184, 189(2003).

97. See Michael J. Kelly, Time Warp to 1945—Resurrection of the Reprisal and Anticipatory Self-DefenseDoctrines in International Law, 13 J. TRANSNAT’L L. & POL. 1, 7–8 (2003).

98. KALSHOVEN, supra note 9, at 36–37. Kalshoven notes that reprisals, though aimed at the offend- Ring state, “almost certainly will have their direct impact on individuals who, as likely as not, are inno-cent of the wrong provoking the reprisal.” Id. at 42.



system may carry out reprisals.99 Classic international legal theory conceivesof the state as the primary, if not sole, legal actor.100 Although moderntheories increasingly support a role for individuals in international law,101 noexisting theory permits individuals to carry out reprisals in their personalcapacities. As a matter of policy, power to approve reprisals is usually re-served to the highest national authority available.102

99. OPPENHEIM’S INTERNATIONAL LAW 138 (Hersch Lauterpacht ed., 6th ed. 1948) [hereinafterOPPENHEIM 2].

100. See HENRY WHEATON, ELEMENTS OF INTERNATIONAL LAW 32 (Coleman Phillipson ed., 5th ed.1916); CHARLES H. STOCKTON, OUTLINES OF INTERNATIONAL LAW 61–63 (1914). Though generallyadhering to the traditional model of international legal personality, Ian Brownlie observes that interna-tional organizations as well as states may satisfy conditions precedent to international personhood.BROWNLIE, supra note 88, at 58–59. International organizations such as the United Nations and regional Rhuman rights bodies are increasingly recognized as powerful actors in international relations and law.The exercise of reprisal rights by international organizations is not, however, well developed in practiceor theory. Kalshoven concludes that international organizations should be included as possible partici-pants in the practice of reprisal. KALSHOVEN, supra note 9, at 28–29. International humanitarian organi- Rzations, including the International Committee of the Red Cross, are not parties to the GenevaConventions. However, in the event that a Protecting Power is unable to fulfill its duties, “the following‘substitutes’ are available to fulfill their duties: ‘an organization which offers all guarantees of impartial-ity and efficacy,’ ‘a neutral State or such an organization,’ or ‘a humanitarian organization, such as theInternational Committee of the Red Cross.’ ” Christiane Bourloyannis, The Security Council of the UnitedNations and the Implementation of International Humanitarian Law, 20 DENV. J. INT’L L. & POL’Y 335, 337(1992) (quoting Common Article 8, ¶ 1 of the First, Second and Third Geneva Conventions and Article9 of the Fourth Geneva Convention). This common article does not explicitly state that the right toreprisal is included in this delegation of responsibilities. See also Brian D. Tittemore, Belligerents in BlueHelmets: Applying International Humanitarian Law to United Nations Peace Operations, 33 STAN. J. INT’L L.61 (1997) (discussing whether U.N. Peacekeeping troops should be subject to the rights and dutiesassociated with International Humanitarian Law). Notwithstanding instances where non-governmentalor supra-national organizations take on the duties of states, it is difficult to imagine them engaging inreprisal.

101. Thus, international human rights law envisions individuals as both beneficiaries and agents ofenforcement. Twentieth century conceptions of human rights posit that individuals benefit from rightsdirectly and merely by virtue of the inherent qualities of being a person. By comparison, traditionalconcepts of international law recognized individual protections only in a derivative sense. Benefits en-joyed by individuals under international law flow indirectly from the person’s status as an agent or aschattel of the state. Modern human rights law also provides for an individual role in enforcement. Anumber of human rights bodies have adopted complaint systems, permitting vindication of rights byindividuals directly against member states. In this regard, individual enforcement in human rights lawdeparts from the classic, sovereign-centric system of state self-help.

102. See U.S. DEP’T OF THE ARMY, FIELD MANUAL 27–10: THE LAW OF LAND WARFARE, ¶ 497(1956):

[Reprisals] should never be employed by individual soldiers except by direct orders of a com-mander, and the latter should give such orders only after careful inquiry into the allegedoffense. The highest accessible military authority should be consulted unless immediate actionis demanded, in which event a subordinate commander may order appropriate reprisals uponhis own initiative.

Id. The Canadian Armed Forces manual provides, “The decision to take reprisal action must therefore beauthorized at the highest political level. Operational commanders on their own initiative are not author-ized to carry out reprisals.” OFFICE OF THE JUDGE ADVOCATE GENERAL OF CANADA, LAW OF ARMED

CONFLICT AT THE OPERATIONAL AND TACTICAL LEVELS, 15–3 (2004). The British Manual of MilitaryLaw includes a similar reservation of authority. MINISTRY OF DEFENCE, BRITISH MANUAL OF MILITARY

LAW, pt. III ¶ 645 (1958). Even the earliest codifications of reprisal doctrine reserved their authorizationto the highest level of command. Accordingly, the Oxford Manual for Military Law of 1880 reservedreprisals to authorization by “the commander in chief.” Institute of International Law, Oxford Manual



Most importantly, reprisals can only be undertaken to induce or compelrenewed compliance with the rule breached. The overarching purpose of re-prisal “is to coerce the addressee to change its policy and bring it into linewith the requirements of international law.”103 Two important restraints onreprisal flow directly from its purpose. First, reprisals are subsidiary.104 Sub-sidiarity requires that states exhaust less drastic means of enforcement, suchas diplomatic protest, prior to resorting to reprisal. It performs the impor-tant function of reducing miscommunication of motives through breaches ofinternational law. Threats or warnings of reprisals are considered prerequi-sites to actual reprisals.105 Second, reprisals must be proportionate to theviolations that provoke them.106 Though it is an ambiguous standard, pro-portionality ensures that the scale of reprisals does not become unmooredfrom its purpose of preventing repeat violations.107 Reprisals include retalia-tory, punitive, and rehabilitative elements, all directed at inducing renewedcompliance. Rather than resurrecting compliance, disproportionate reprisalshave the effect of provoking further retaliation. Proportionality purports torestrain such cycles of escalating breaches.

There are tempting connections to be drawn between the principal ofreciprocity and the practice of reprisal. At the most basic level, each consti-tutes a state response to a counterpart’s breach. Reciprocity and reprisal arethus closely related as means of state self-help in the international legal sys-tem. Each is also a product of states’ peculiar status as both subjects andauthorities in the international legal system.108 Early attempts to codify au-thority and limits concerning reprisal and reciprocity often conflated thetwo or grounded the former in the latter.109 Yet important distinctions dif-ferentiate reciprocity from reprisal and illustrate the theoretical foundationsof each form of sanction.

1880: The Laws of War on Land, in THE LAWS OF ARMED CONFLICTS 29, art. 86 (D. Schindler & J. Tomaneds., Martinus Nihjoff 1988) (1880) [hereinafter Oxford Manual].

103. KALSHOVEN, supra note 9, at 33. R104. Id. The International Arbitrators in the Naulilaa Case noted that German reprisals should have

been preceded by a demand for reparations. Naulilaa Case, supra note 95. R105. Darcy, supra note 96, at 193. R106. Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, 1996 I.C.J. 226, 246, ¶

46 (July 8); Naulilaa Case, supra note 95; KALSHOVEN, supra note 9, at 33. R107. MYERS S. MCDOUGAL & FLORENTINO P. FELICIANO, LAW AND MINIMUM WORLD PUBLIC ORDER

682 (1961).108. KALSHOVEN, supra note 9, at 21–22 (“International society is characterized by the ambiguous R

position of States as member-subjects and authorities at the same time.”).109. See Oxford Manual, supra note 102, art. 84. “Reprisals are an exception to the general rule of R

equity, that an innocent person ought not to suffer for the guilty. They are also at variance with the rulethat each belligerent should conform to the rules of war, without reciprocity on the part of the enemy.”Id. While the Manual formed the basis for negotiations that produced the Hague Regulations of 1899,its observations on reprisals and reciprocity were not reproduced.

Uncharacteristically, Lauterpacht adds some confusion in his description of reciprocity as an element ofreprisal. Lauterpacht describes “negative reprisal” as “refusal to perform such acts as are under ordinarycircumstances obligatory, such as the fulfilment of a treaty obligation or the payment of a debt.” OP-PENHEIM 2, supra note 99, at 140. R



Negative reciprocity and reprisal differ most significantly in their respec-tive effects on the underlying legal rule.110 Reprisal assumes, and seeks tocompel, continued operation of the law in question. In this sense, reprisalaffirms international law, reflecting the importance and value that statesplace on compliance.111 The temporal component of reprisal is illustrative:international law authorizes reprisals only while the offending state persistsin breach.112 The offending state extinguishes the legal basis for reprisalwhen it realigns itself with the norm in question. Negative reciprocity, bycontrast, suspends or terminates the legal obligation altogether. Actions jus-tified by failure of reciprocal observance regard the law in question as extin-guishable or entirely inapplicable in the event of breach.

Unlike reprisal, reciprocity is not formally subject to the requirements ofsubsidiarity and proportionality.113 To exercise negative reciprocity, statesneed not necessarily exhaust other means of sanction. Material breach is suf-ficient. Furthermore, negative reciprocity can be exercised in an anticipatorysense. Faced with persistent evidence that a counterpart intends not to honora legal rule, a state might reasonably regard the norm as inapplicable in itsrelations with that counterpart. Obligational reciprocity permits states tosuspend or withhold operation of a legal rule without waiting for a materialbreach. Recurring objections to a norm in question, formal treaty reserva-tions, and consistent patterns of state practice would indicate future intentto disregard an international norm. In this sense, obligational reciprocityoperates less like a sanction than a mere determination of applicability—inother words, as a secondary rule of international law.

The principle of negative reciprocity operates under other restraints thatdo not limit the practice of reprisal. Negative reciprocity operates with re-spect to particular provisions of international law. As a general matter, thereach of reciprocity is limited to the rule breached or repudiated. Legal doc-trine limits suspension of entire legal covenants or regimes in favor of sus-pension of the particular provision breached by a counterpart.114 Negativereciprocity does not authorize suspension or termination of unrelated or evencollateral legal norms. Reprisal is not similarly restricted. Reprisal may takethe form of breach of an entirely separate or unrelated legal provision.115 Forinstance, in response to a breach of diplomatic immunity, a state may violatethe protected economic interests of the state concerned, so long as it ob-serves the principles of subsidiarity and proportionality. In this regard, the

110. Maurice Greenspan notes, “Reprisals are illegitimate acts of warfare, not for the purpose ofindicating abandonment of the laws of war, but, on the contrary, to force compliance to those laws.”MAURICE GREENSPAN, THE MODERN LAW OF LAND WARFARE 407–08 (1959).

111. KALSHOVEN, supra note 9, at 43. R112. Christopher Greenwood, The Twilight of the Law of Belligerent Reprisals, 20 NETH. Y.B. INT’L L.

45–46 (1989).113. KALSHOVEN, supra note 9, at 363. R114. Vienna Convention, supra note 27, art. 60, ¶¶ 1–3. R115. Kalshoven observes that “reprisals need not affect the same norm as has been violated by the

original offender.” KALSHOVEN, supra note 9, at 25. R



means selected for reprisal are a function of anticipated effect on compliancerather than an effort to match or reciprocate the addressee’s breach.116 Bycontrast, reciprocity is an effort to reestablish a position of equality—a level-ing of comparative legal obligations and conduct.

III. RECIPROCITY AND THE DEVELOPMENT OF THE LAW OF WAR

The law of war has always included its own system of secondary rules thatsupplement the rules that apply to all international law.117 This section ar-gues that the history of the law of war and its relationship with reciprocityreveals a trajectory of development, refinement, and obscuration of reciproc-ity doctrine. The law of war has long included strong evidence of conditionsof reciprocity in both its specific and diffuse forms.118 The earliest laws ofwar relied on professional custom and ensured reciprocal observance by re-stricting application to elite classes of combatants. Later positive provisionsincluded express conditions on application that vindicated similar concernsover combatants’ capacity and willingness to observe constraints. Whilesome of these provisions were enforced only sporadically and ultimately van-ished, they were often replaced by veiled conditions on the application of thelaw of war that had much the same effect as explicit conditions of reciproc-ity. At times, state reservations reinforced restrictive provisions on applica-tion. Even after the most important and humanitarian-focused revision ofthe law of war in 1949, reciprocity was never entirely eliminated in a posi-tivist sense. Rather, conditions of reciprocity merely changed form.

A. Early History

Just as warfare has always included restraints on conduct,119 the law ofwar has nearly always limited the application of its rules to specified circum-stances and persons. Although prohibitions on inhuman or unnecessary kill-ing and destruction are nearly universal, they are also nearly universallyqualified. Numerous exceptions have succeeded the seemingly categoricalinjunction, “Thou shalt not kill.”120 Jean-Jacques Fresard observes that“[r]eligions themselves are the first to specify, more or less explicitly, thatthe injunction concerns above all our people. The others, the ‘unbelievers,’infidels and apostates, may be run through by the swords of men when theyare not simply delivered up to the sword of God.”121 For example, ancient

116. According to Kalshoven, “[I]n selecting a reprisal action the decision-makers in the State will beguided by considerations of estimated effect rather than reciprocity . . . .” Id.

117. See supra discussion accompanying notes 21–26, discussing secondary rules in international law. R118. See supra discussion accompanying notes 16–20. R119. See PERCY BORDWELL, LAW OF WAR 8–9 (1908) (noting “incidents of humanity” in conflict in

ancient Hindu and Aryan civilizations).120. JEAN-JACQUES FRESARD, THE ROOTS OF BEHAVIOR IN WAR 22 (2004) (quoting Exodus 20:13).121. Id.



Hebrews distinguished protections for civilians belonging to immediate en-emies from civilians belonging to remote enemies. Drawn from the Bible,such customs permitted a free hand in dealing with the former, even permit-ting genocide, while protecting the latter and their property from arbitraryviolence.122

Although strong evidence supports the law of war’s religious founda-tions,123 a second wellspring for many early restraints on conduct in war wasthe sense of fraternity between belligerents.124 The military class developed asense of respect and honor that called for restraint among its members.Combatants began to appreciate the long-term benefits of such restraints ashonoring surrenders and respecting the wounded comrades and enemiesalike.125 Only the warrior class observed these rules.126

The preterit law of war always operated most reliably between the profes-sional military classes of homogeneous cultures.127 Some have argued that itsrestrictive application resulted from the conclusion that only members of theprofessional military class could guarantee compliance with battlefield pro-scriptions.128 A common thought was that only those schooled in the cus-toms and traditions of organized combat would observe its elaborateconstraints—undoubtedly, an early manifestation of reciprocity. Further-more, the relatively limited and conjunct class of combatants ensured ac-countability for atrocities. Acts of treachery ignited costly and prolongedblood feuds.129 Restraint tended to diminish in conflicts between elites andlower social orders where such vengeance-based sanctions were unlikely.130

122. 1 THE LAW OF WAR: A DOCUMENTARY HISTORY 4 (Leon Friedman ed., 1972) (citing Deuteron-omy 20:10–17).

123. See STEPHEN C. NEFF, WAR AND THE LAW OF NATIONS 45 (2005) (describing the evolution ofjust war doctrine from Christian theology).

124. Michael Howard observes, “Restraint on war grew out of the cultures of the war-making socie-ties, rather than being imposed on them by some transcendent moral order.” Michael Howard, Con-straints on Warfare, in THE LAWS OF WAR 2 (Michael Howard et al. eds., 1994).

125. Id. at 3.126. The terms bellum romanum and guerre mortelle often refer to early European conflicts fought against

barbarians or infidels without restraint or discrimination. Id. Bellum romanum was waged against threecategories of enemy: “rebels, infidels, and ‘savages.’ ” Id. at 5.

127. Id. at 3 (explaining that earliest norms of combat applied as matters of professional respectbetween elite classes of warriors and were generally not extended to “barbarians” or “infidels”). GeoffreyBest observes, “[E]veryone with strong experience of the active conduct of war understood two thingsvery well: first, that its laws and customs could only be observed in relation to circumstances and, second,that in any ordinary tussle between law and military necessity, law would have to be accommodating.”GEOFFREY BEST, LAW AND WAR SINCE 1945, at 22 (1997).

128. For example, Robert Stacey observes, “The laws of war governing pitched battles were quitedetailed, but they applied only to knights and squires, in the later Middle Ages the only two groupscapable of bearing heraldic insignia.” Robert C. Stacy, The Age of Chivalry, in THE LAWS OF WAR, supranote 124, at 36. R

129. See Geoffrey Parker, Early Modern Europe, in THE LAWS OF WAR, supra note 124, at 54. R130. See id.; Harold Selesky, Colonial America, in THE LAWS OF WAR, supra note 124, at 59 (observing R

that controls over the use of force “slip . . . away on the margins”). Selesky notes a high level of barbarityin engagements between English and French forces where the latter extensively employed Native Ameri-can forces. Id. at 57–58. Confronted with an unfamiliar enemy, English soldiers did not observe therestraints associated with conflicts between professional armies. Id. at 85.



Geoffrey Parker suggests that durability of relations was the essential condi-tion for restraint in war in pre-Enlightenment Europe, because it provided“some certainty that the two sides will meet again.”131

In the late eighteenth and early nineteenth centuries, professional frater-nity and shared cultural identity receded as the foundations for restraint inwar. Law of war historians note the development of relatively less exclusivebehavioral customs in later periods of Western warfare. Their works suggesta convergence of natural law, military law, ecclesiastical precept and selfinterest.132 However, restraints of the period had more to do with improvingdiscipline and preventing distractions associated with looting and pillagingthan with vindicating humanitarian concerns or universal rules of combat.133

Thus while combatants began to recognize practical advantages to mutualrestraint, the code that emerged remained in most respects “a contractualetiquette of belligerence” conditioned on opponents having both the capac-ity and resolve to respect its terms.134

B. The Early Positive Law of War

Until the late eighteenth century, custom was nearly the sole source ofinternational regulation of warfare. But by the mid-nineteenth century, cus-tom had become sufficiently refined to be regarded as a “common law ofwar.”135 Custom had the advantage of widespread applicability but lacked

131. Parker, supra note 129, at 57. Surveying the Napoleonic Wars of the early nineteenth century, RGunther Rothenberg observes that self interest of combatants played an important role in the operationof restraints on warfare. Gunther Rothenberg, The Age of Napoleon, in THE LAWS OF WAR, supra note 124, Rat 97. Rothenberg argues that the traditional accounts of hostilities devolving from highly regulatedencounters into total chaos are greatly exaggerated. Id. Accounting for exceptions, Rothenberg notes thatcombatants largely observed the laws and customs of warfare out of self interest with significant collateralhumanitarian impact. Id.

Robert Axelrod offers similar observations concerning the importance of repeat encounters to thedevelopment of cooperation between parties. ROBERT AXELROD, THE EVOLUTION OF COOPERATION 129(1984). He explains that during World War I, the immobile and static nature of trench warfare ensuredprolonged interaction between small military units. Prolonged interaction permitted patterns of coopera-tion based on reciprocity to develop between enemies. Id. Specifically, Axelrod notes a system of “live-and-let-live” wherein each side declined to engage or kill the other. Id. at 74.

132. Parker, supra note 129, at 42; see also Howard, supra note 124, at 4 (“[T]here were beginning to Rcreep into the conduct of war not only prudential but ethical constraints on their treatment.”).

133. BEST, supra note 127, at 34 . R134. Parker, supra note 129, at 41. Geoffrey Best observes, “Humanitarian commentators in our own R

time too easily fall into the good-natured error of transferring their universalist principles on to ages andpeoples whose views of their own species were strictly discriminatory.” BEST, supra note 127, at 24–25. R

135. Emer de Vattel mentions the customary status of the law of war in his early nineteenth centurywork on the law of nations:

The war being reputed equal between two enemies, whatever is permitted to one, in virtue of thestate of war, is also permitted to the other. Accordingly no nation under pretence of justice beingon its side, ever complains of the hostilities of the enemy, while they observe the terms pre-scribed by the common laws of war.

EMER DE VATTEL, THE LAW OF NATIONS, OR, PRINCIPLES OF THE LAW OF NATURE, APPLIED TO THE

CONDUCT AND AFFAIRS OF NATIONS AND SOVEREIGNS: A WORK TENDING TO DISPLAY THE TRUE INTER-

EST OF POWERS 447 (Nicklin & Johnson eds., 1829).



clarity. Although states could not mandate universal consent, they eventu-ally clarified the law of war through international legal instruments.

1. Early Law of War Treaty Provisions

Reciprocity figured prominently in the earliest treaty-based law of warprovisions. The first international legal instruments to regulate warfare werebilateral treaties. These instruments were not aimed at regulating warfareper se but were rather broad efforts to maintain peaceful and productiverelations between states.136 The articles that addressed the law of war werebrief and subsidiary to the purpose of the treaties. Scholars credit the U.S.-Prussia Treaty of Amity and Commerce as one of the earliest positive inter-national formulations of restraint on the conduct of land warfare.137 Thetreaty established rules of neutrality in case either state engaged in war witha third state,138 guaranteed safe return to civilians in the event of war be-tween the parties139, and provided for the safe and open detention of prison-ers of war.140

Upon first inspection, the Treaty of Amity appears to be conditioned onobligational and observational reciprocity. Indeed, the Treaty preamble re-cites reciprocity as a basis for the agreement.141 However, the Treaty’s provi-sions on the law of war were insulated from at least one general justificationfor suspension, termination in the event of war. The Treaty explicitly stated

136. See DOCUMENTS ON THE LAWS OF WAR 4–5 (Adam Roberts & Richard Guelff eds., 3d ed. 2000)(noting bilateral treaties also used to fix obligations of neutrality since the early seventeenth century)(citing W.E. HALL, THE RIGHTS AND DUTIES OF NEUTRALS 27–46 (1874)).

137. Treaty of Amity and Commerce Between his Majesty the King of Prussia and the United Statesof America, U.S.-Prussia, Sept. 10, 1785 [hereinafter U.S.-Prussia Treaty of Amity and Commerce],reprinted in DIETRICH SCHINDLER & JIRI TOMAN, THE LAWS OF ARMED CONFLICT (4th ed. 2004). Twobilateral treaties that preceded the U.S.-Prussia Treaty of Amity and Commerce dealt primarily withmaritime legal customs. See THE LAW OF WAR: A DOCUMENTARY HISTORY, supra note 122, at 149 R(citing Treaty of Amity and Commerce Between the United States of American and his Most ChristianMajesty, U.S.-Fr., Feb. 6., 1778, 8 Stat. 12 [hereinafter U.S.-Prussia Treaty of Amity and Commerce];Treaty of Amity and Commerce between their High Mightinesses the United Netherlands, and theUnited States of America, U.S.-Neth., Oct. 8, 1782, 8 Stat. 32).

138. U.S.-Prussia Treaty of Amity and Commerce, supra note 137, art. 12. R139. Id. art. 23. Article 23 took its form from a nearly identical clause proposed for the peace treaty

concluding the American Revolutionary War. BORDWELL, supra note 119, at 69–70. Benjamin Franklin Rdrafted the original proposal to the U.S.-Great Britain Treaty of Peace and saw that it was included inthe U.S.-Prussian Treaty. Id. at 70.

140. U.S.-Prussia Treaty of Amity and Commerce, supra note 137, art. 24. Protections for prisoners of Rwar included freedom from confinement in dungeons, prisons or ships; a prohibition on shackling; ra-tions comparable to those provided to forces of the detaining power; and receipt of comfort items andsupplies. Id.

141. Id. pmbl. The Treaty’s preamble states:

His majesty the King of Prussia, & the United States of America, desiring to fix, in a perma-nent and equitable manner, the rules to be observed in the intercourse and commerce theydesire to establish between their respective countries, his majesty & the United States havejudged that the said end cannot be better obtained than by taking the most perfect equality and reciproc-ity for the basis of their agreement.

Id. (emphasis added).



that it would persist in case of war between the parties, eliminating theoption to exercise negative reciprocity.142

States continued to enact bilateral treaties to regulate conduct in war con-tinued through the mid-nineteenth century.143 However, records of statepractice concerning these treaties are scant. Beyond the language of the trea-ties themselves, there is little evidence to show how the principle of reci-procity bore on observance, suspension, or termination of treaty obligations.The conclusion of such treaties certainly suggests some reciprocal commit-ment to the principles included therein. Perceptions about which otherstates would likely reciprocate may have contributed to the limited and bi-lateral nature of these treaties. Limits on termination and suspension of theseinstruments usually precluded the option of resorting to arms in retaliationfor breach. On the other hand, resort to negative reciprocity, particularlysuspension of a breached provision, does not seem entirely foreclosed bytheir text.

2. The U.S. Lieber Code

Despite the formative role of bilateral treaties in the effort to codify cus-tomary restraints on warfare, the most influential nineteenth century codifi-cation of the law of war was not itself an international instrument. Just as

142. Id. The preamble goes on to state:

& it is declared, that neither the pretence that war dissolves all treaties, nor any otherwhatever, shall be declared as annulling or suspending this & the next preceding article, buton the contrary, that the state of war is precisely that for which they are provided, & duringwhich they are to be as sacredly observed as the most acknowledged articles in the law ofnature or nations.

Id. The last clause suggests a persistence or immunity from conditions of reciprocity, recognizing a nearlyperemptory status for the norms of Articles 23 and 24. It is uncertain how the parties envisioned thisprovision would interact with the preamble’s stated commitment to the principle of reciprocity.

143. See, e.g., Treaty of Peace and Amity, concluded between the United States of America and theDey and Regency of Algiers, Feb. 11, 1822, reprinted in 2 TREATIES AND OTHER INTERNATIONAL ACTS OF

THE UNITED STATES OF AMERICA (Hunter Miller ed., 1931). The Treaty guaranteed safe passage todiplomats and civilians in case of war between the parties. The parties disclaimed resort to war as aresponse to breach prior to a three-month period of notice and redress. Id. art. 16. The Treaty did notaddress retaliation or reciprocity more explicitly. See also Chilean-American Diplomacy Convention ofPeace, Amity, Commerce, and Navigation, U.S.-Chile, May 16, 1832, available at http://avalon.law.yale.edu/19th_century/chile01.asp. The Treaty guaranteed the safe return of civilians from occupied territoryin the event of war. Id. art. 23. Article 31 relegated retaliation for breach, including either negativereciprocity or reprisal, to a subsidiary status. Id. art. 31. In the event of breach, both states agreed to servenotice and provide an opportunity for redress prior to exercising traditional forms of state self-help. Id.Reciprocity assumes a central place in the Treaty by virtue of the following opening passage from thepreamble:

[D]esiring to make firm and lasting the friendship and good understanding which happilyprevail between both nations, have resolved to fix, in a manner clear, distinct and positive, therules which shall in future be religiously observed between the one and the other, by means of a treaty. . . .”

Id. pmbl. (emphasis added). In 1872, the United States and the Netherlands agreed, in the event ofhostilities, to allow a nine-month evacuation period for the citizens of each state, “in all freedom andwithout hindrance.” THE LAW OF WAR: A DOCUMENTARY HISTORY, supra note 122, at xiv. R



surprising, the instrument in question arose in the context of a domesticconflict. U.S. General Order No.100 of 1863—commonly called the LieberCode after its author and promoter, Dr. Francis Lieber—is widely creditedwith kicking off the late nineteenth century trend of codifying the customsand usages of war into multilateral treaties.144 In addition to codifying pre-existing norms of respect for wounded combatants and prisoners, the LieberCode added significantly to prevailing military custom.145 The Code dealt

144. UNITED STATES WAR DEPARTMENT, INSTRUCTIONS FOR THE GOVERNMENT OF ARMIES IN THE

FIELD (General Orders No. 100, prepared by Francis Lieber, L.L.D.) (1863) [hereinafter Lieber Code].Roberts and Guelff affirm the influence the Lieber Code had on future national and international law ofwar instruments. DOCUMENTS ON THE LAWS OF WAR, supra note 136, at 12–13. R

The Lieber Code was a starting point for many international treaty conventions in the late nineteenthand early twentieth centuries. “Perhaps the landmark international breakthough came at the Hague in1899 with the signing by twenty-four nations of the ‘Convention with Respect to the Laws and Customsof War on Land.’ This document ‘leaned heavily’ on the Lieber code established in the U.S. . . . . ” RonSievert, A New Perspective on the International Criminal Court: Why the Right Should Embrace the ICC and HowAmerica Can Use It, 68 U. PITT. L. REV. 77, 89 (2006); see Corrine Brenner, Cultural Property Law:Reflecting the Bamiyan Buddhas’ Destruction, 29 SUFFOLK TRANSNAT’L L. REV. 237, 240 (2006) (citing theLieber code as the basis for protecting cultural property during war-time); Mary Deutsch Schneider,About Women, War and Darfur: The Continuing Quest for Gender Violence Justice, 83 N.D. L. REV. 915, 923(2007) (citing the Lieber code as codifing sexual violence as a war crime).

To be sure, the Lieber Code was not the first articles of war issued to an army. Barbara Donagan notesthat several early articles of war and even permanent legislation governed sixteenth and seventeenthcentury armies. Barbara Donagan, Codes of Conduct in the English Civil War, in 118 PAST AND PRESENT 65,74–76 (1988). Such codes typically prescribed conduct of loyalty, but also included restraints on conducttoward civilians. Id. at 82. Examining legal limitations on seventeenth century European armies, Dona-gan identifies three primary sources of restraint: the law of nature and nations, the law of war, andmilitary law. Id. at 74–75.

The pre-Lieber Code 1856 Paris Declaration Respecting Maritime Law is widely acknowledged to bethe first multilateral law of war instrument. Paris Declaration Respecting Maritime Law, Apr. 16, 1856,46 BFSP 26, reprinted in DOCUMENTS ON THE LAWS OF WAR, supra note 136, at 47–49. The Declaration Rdid not address humanitarian concerns beyond respect for property and duties of neutral powers. Partiesto the Declaration agreed to limit the use of privateers and the seizure of neutral property at sea. Id. at49. As evidence that its rules were based on obligational reciprocity, the Declaration’s penultimate clauselimits the parties’ obligations to states that have acceded to the Declaration. Id.

145. During the American Civil War, Lieber wrote:

How far rules which have formed themselves in the course of time between belligerents mightbe relaxed with safety toward the evildoers in our civil war; or how far such relaxation ormitigation would be likely to produce a beneficial effect upon an enemy who, in committing agreat and bewildering wrong, seems to have withdrawn himself from the common influencesof fairness, sympathy, truth and logic-how far this ought to be done at the present momentmust be decided by the executive power, civil and military, or possibly by the legislativepower. It is not for me in [this] place to make the inquiry. So much is certain, that no army, nosociety engaged in war, any more than a society at peace, can allow unpunished assassination,robbery, and devastation without the deepest injury to itself and disastrous consequenceswhich might change the very issue of the war.

RICHARD SHELLY HARTIGAN, LIEBER’S CODE AND THE LAW OF WAR 12, 13, 19–20 (1983); see StephenW. Simpson, Shoot First, Ask Questions Later: Double Tapping Under the Laws of War, 108 W. VA. L. REV.751, 759–60 (2006) (noting the importance of the Lieber Code as the precursor to the modern laws ofwar).



explicitly with regulation of occupied territory,146 guerrilla tactics,147 andeven protections for civilians and their property.148

Despite its encouraging humanitarian provisions, the Lieber Code took aharsh view of reciprocity. The Code provided, “The law of war can no morewholly dispense with retaliation than can the law of nations, of which it is abranch. Yet civilized nations acknowledge retaliation as the sternest featureof war.”149 Subsequent articles reinforce the Lieber Code’s tolerance for retal-iation by permitting the suspension of the Code’s protections in the event ofenemy abuses.150

It is unclear whether the Code’s references to retaliation meant to reservea right to exercise negative reciprocity, belligerent reprisals, or both.151 Ex-plaining the conditions for resort to retaliation, the Code notes only retribu-tive goals.152 Reciprocity and retaliation share “the idea of doing the samething in response to something.”153 Like negative reciprocity, retributiveretaliation suggests an intent to balance accounts between forces rather thanto inspire future compliance, the hallmark of belligerent reprisal.

In its final section, the Code addresses the law of war’s scope of applica-tion. The Code regarded the application of the laws and customs of war tointernal conflicts as a matter of state discretion.154 Presaging later qualifica-tions on rules applicable to internal conflicts, the Code denied that a state’sdecision to apply the law of war had any legal effect on the legitimacy of

146. Lieber Code, supra note 144, arts. 1–7. R147. Id. arts. 81–85.148. Id. art. 23.149. Id. art. 27.150. Id. arts. 61–62. Stone offers support for associating retaliation with reciprocity. JULIUS STONE,

LEGAL CONTROLS OF INTERNATIONAL CONFLICT 354 (2d ed. 1959) (“The premise on which retaliation inwar proceeds is, indeed, that a belligerent’s duty to observe the laws of war is not absolute, but condi-tional on the enemy’s reciprocation.”).

151. The first edition of Colonel William Winthrop’s highly influential treatise on Military Law doesnot address reciprocity. WILLIAM WINTHROP, MILITARY LAW AND PRECEDENTS (1886). His omissionmay not be surprising given that the positive law of war was still primarily restricted to national codesand instructions to armed forces. The major efforts to develop multilateral treaties on the law of war werestill in nascent stages when Winthrop wrote. The omission of conditions of reciprocity from the secondedition of Winthrop’s work in 1920 is less easily explained. WILLIAM WINTHROP, MILITARY LAW AND

PRECEDENTS (2d ed. 1920). The preface to the second edition advertises a material supplement to theprevious edition’s law of war section. Id. at 7. Yet the section draws exclusively on pre-twentieth centurysources for support, despite major multilateral codifications of the law of war at the 1899 and 1907Hague Conferences. See infra Part III.C. It may be best to understand Winthrop’s work on the law of war,including the 1920 update, as a limited survey of nineteenth century custom.

152. Lieber Code, supra note 144, art. 28. Article 28 reads: R

Retaliation will, therefore, never be resorted to as a measure of mere revenge, but only as ameans of protective retribution, and moreover, cautiously and unavoidably; that is to say,retaliation shall only be resorted to after careful inquiry into the real occurrence, and thecharacter of the misdeeds that may demand retribution.

Id.153. ZOLLER, supra note 9, at 14. Zoller notes that the Latin root of retaliation, “talio,” developed R

from “talis” meaning “of the same quality.” Id.154. Lieber Code, supra note 144, art. 152. R



insurrection or rebellion.155 The Code does not indicate whether a rebelforce’s compliance could compel reciprocal state observance. Humanitarianconcerns are the only cited justification for applying the regular law of warto rebels.156 Although technically not binding on Confederate forces, theCode’s retaliation provisions clearly anticipated reciprocal observance by thearmed forces of the South. With the exception of its use of guerilla warfare,the Confederate Army was in most respects a peer of the Union Army.157 Infact, a significant portion of the United States’ pre-Civil War professionalmilitary class had defected to the South.158 The Code granted belligerent—and consequently prisoner of war—status to a broad range of Confederateparticipants, including partisans,159 sutlers,160 reporters,161 and scouts. Onlyspies, traitors, and brigands not formally incorporated into the Confederacy’sforces were categorically excluded from protection.162 The Code thus ex-pressed a strong preference for protecting conventional forces similar tothose of the state in organization and conduct.

155. Id. See generally DONALD A. WELLS, THE LAWS OF LAND WARFARE: A GUIDE TO U.S. ARMY

MANUALS 3 (1992). States have included similar caveats in modern international conventions regulatinginternal armed conflicts. Common Article 3 of the four 1949 Geneva Conventions provides, “The appli-cation of the preceding provisions shall not affect the legal status of the Parties to the conflict.” Conven-tion for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field art. 3,Aug. 12, 1949, 6 U.S.T. 3114, 75 U.N.T.S. 31 [hereinafter 1949 Geneva Convention I]; Convention forthe Amelioration of the Condition of the Wounded, Sick, and Shipwrecked Members of Armed Forces atSea art. 3, Aug. 12, 1949, 6 U.S.T. 3217, 75 U.N.T.S. 85 [hereinafter 1949 Geneva Convention II];Convention Relative to the Treatment of Prisoners of War art.3, Aug. 12, 1949, 6 U.S.T. 3316, 75U.N.T.S. 135 [hereinafter 1949 Geneva Convention III]; Convention Relative to the Protection of Civil-ian Persons in Time of War art. 3, Aug. 12, 1949, 6 U.S.T. 3516, 75 U.N.T.S. 287 [hereinafter 1949Geneva Convention IV].

156. Lieber Code, supra note 144, art. 152. R157. Although the Confederate Army only mobilized one million troops to the Union Army’s 2.6

million, the composition of the two armies was similar. Both consisted of relatively small classes ofofficers and enlisted men with overwhelming numbers of new recruits. Since the Confederate Army wasled by West Point graduates, its organization scheme was almost identical to the regular U.S. Army, andby extension the Union Army. The methods employed by the Confederate Army mirrored French EcolePolytechnique and the Napoleonic model. See Robert M. Epstein, The Creation and Evolution of the ArmyCorps in the American Civil War, 55 J. MILITARY HIST. 21, 22 (1991); see also HERMAN HATTAWAY &ARCHER JONES, HOW THE NORTH WON: A MILITARY HISTORY OF THE CIVIL WAR 10 (1983).

158. See HATTAWAY & JONES, supra note 157. Many officers from Southern states were either dis- Rmissed or allowed to resign from the Army at the beginning of the Civil War. Prior to resignations ordismissals, 1,105 officers were in the regular army. Id. Of this group, 809 officers remained with theUnion army and 270 officers joined the confederacy. Id. The officers were almost all professionallytrained at West Point. Id. “West Point graduates on the active list numbered 824; of these, 184 becameConfederate officers. Of the approximately 900 military academy graduates then in civilian life, 114returned to the Union army and ninety-nine others acquired southern commissions.” Id. Incidentally,Henry Heth, the West Point graduate who translated the French tactical guide used by both armies inthe Civil War, later defected to serve in the Confederate Army. Epstein, supra note 157 at 23. R

Geoffrey Best posits that the Lieber Code may have been a response to the character of the UnitedStates’ new enemy. Led by gentlemen and former members of its own armed forces, the Union Armycould not have employed practices used against “Red Indians and Mexicans.” BEST, supra note 127, at R41.

159. Lieber Code, supra note 144, art. 81. R160. Id. art. 50.161. Id.162. Id. arts. 82–84, 90–91, 103.



The Lieber Code was a great textual advance for positive humanitarianconcerns in war.163 The Code is well-understood as a codification of the gen-eral common law of war applied as a matter of policy to a civil war.164 De-spite its humanitarian attentions, the Code was conditioned on observationalreciprocity. A series of efforts inspired by the Code demonstrated the contin-ued role of reciprocity in international codifications of the common law ofwar.

3. Early Multilateral Law of War Treaties

Enthusiasm for codifying the law of war spread through Europe at the endof the nineteenth century. Pursuing diverse objectives, multiple efforts con-tinued Lieber’s work. A Swiss businessman who observed the intense suffer-ing of wounded and sick combatants at the Battle of Solferino led themovement that produced the 1864 Geneva Convention and its iterative in-carnations.165 A scant ten articles, the Convention focused exclusively onhumanitarian concerns for the wounded and contained no explicit limits onapplication or conditions of reciprocity.

However, other contemporaneous treaties placed far more emphasis onreciprocity. In 1868, Czar Alexander II of Russia invited the world’s majorpowers to St. Petersburg, a gathering which resulted in a declaration thatrenounced the use of exploding or inflammable substances in light projec-tiles.166 But the binding force of the Declaration was conditioned on thestrictest obligational reciprocity. By its terms, the Declaration applied onlyto conflicts comprised exclusively of states parties to the treaty.167 The Dec-laration did not address consequences of breach between parties, presumablyleaving questions of negative reciprocity to international law.

163. Deplorable conditions of confinement for some prisoners of war and instances of indiscriminatecampaigns caution against championing the Lieber Code as a practical success at humanizing the Ameri-can Civil War. See ROBERT KNOX SNEDEN, EYE OF THE STORM : A CIVIL WAR ODYSSEY (2000); EARL

SCHENCK MIERS, THE GENERAL WHO MARCHED TO HELL: WILLIAM TECUMSEH SHERMAN AND HIS

MARCH TO FAME AND INFAMY (1951).164. The United States reissued General Order 100 to its armed forces during the Spanish-American

War. WELLS, supra note 155, at 4–5. R165. HENRY DUNANT, A MEMORY OF SOLFERINO (Am. Red Cross trans., 1986) (1862); see ANGELA

BENNETT, THE GENEVA CONVENTION (2005) (reciting a detailed personal history of Dunant’s efforts tobring about the first Geneva Convention).

166. Id. at 54.167. The Declaration provided in relevant part:

This engagement is obligatory only upon the Contracting or Acceding Parties thereto, in caseof war between two or more of themselves: it is not applicable with regard to non-ContractingParties, or Parties who shall not have acceded to it.

It will also cease to be obligatory from the moment when, in a war between Contracting orAcceding Parties, a non-Contracting Party or a non-Acceding Party shall join one of thebelligerents.

Id.



In 1874, again on the initiative of the Russian Czar, European states con-vened in Brussels to draft an agreement on the laws and customs of war.168

The Brussels Conference undertook a much broader codification than itspredecessor, addressing authority over occupied territory, means and meth-ods of warfare, combatant status, and prisoners of war.169 It also incorporatedthe 1864 Geneva Convention by reference.170 However, the Brussels Decla-ration lacked support and suffered from substantive disagreements betweenless powerful states and Europe’s perennial military powers. Attempting asimilarly broad codification of the law of war, the International Law Insti-tute produced the 1880 Laws of War on Land.171 Perhaps mindful of statereluctance encountered at Brussels, its authors issued the Oxford Manual,intended for distribution by states to their armed forces. Like the BrusselsDeclaration, the Oxford Manual appears to have been merely a draft proposalrather than an authoritative or binding progression in the law of war.

Unlike their immediate predecessors and successors, neither the BrusselsDeclaration nor the Oxford Manual addressed reciprocity in either the obli-gational or observational sense. The limited effect of each instrument wasdoubtless the product of politics, diplomacy, and timing. Yet with the ex-ception of the omission of reciprocity, their similarity in substance to con-temporaneous instruments is striking.

C. Reciprocity and the Hague Tradition172

Although they were innovative in many respects, the conventions pro-duced at the Hague Peace Conferences of 1899 and 1907 resembled theirpredecessors in their insistence on reciprocity as a condition of application.

1. The Origins of the Hague Conventions

Still hopeful of achieving peace and limiting the effects of war throughinternational law, as well as perhaps vindicating political and security con-cerns, Czar Nicholas II initiated the First Hague Peace Conference in

168. See PROJECT OF AN INTERNATIONAL DECLARATION CONCERNING THE LAWS AND CUSTOMS OF

WAR (Aug. 27, 1874), available at http://www.icrc.org/ihl.nsf/INTRO/135?OpenDocument.169. Id. Actually called a “project,” the Brussels Conference was not formally authorized to conclude

a treaty but had hoped to produce a agreement on principles that states might endorse. See THE LAW OF

WAR: A DOCUMENTARY HISTORY, supra note 122, at 152. R170. Project of an International Declaration concerning the Laws and Customs of War, supra note

168. R171. Oxford Manual, supra note 102. R172. Law of war scholars have noted a bifurcation of the modern jus in bello between rules derived from

the Hague Regulations of 1899 and 1907 and rules usually appearing in the various iterations of theGeneva Conventions. The former rules are typically said to be of the Hague Tradition and concernprimarily regulation of the means and methods used in warfare. Rules derived from the so-called GenevaTradition typically focus on protections for the victims of warfare, including the wounded, sick,shipwrecked, and civilians. The bifurcation has always been slightly artificial as each tradition hasconsistently overlapped with the other. For instance, both the Hague and Geneva Traditions addressprotections for prisoners of war.



1899.173 The Conference produced highly contentious discussions on armslimitations, the use of international arbitration and mediation to avoid war,and naval operations. By comparison, the Conference’s effort at codifyingregulations of land warfare proved easy.174 The U.S. delegation reportedstrong similarities between the proposed regulations for land warfare and thestill-operative Lieber Code.175 The influence of the 1874 Brussels Declara-tion was clear in the Conference’s organization and agenda. Ultimately, theConference produced the 1899 Convention with Respect to Laws and Cus-toms of War on Land.176 The Conference placed the bulk of the Conven-tion’s substantive provisions in an annex of regulations containing 60articles.177

Shortly after the 1899 Conference concluded, there were calls for a secondConference.178 In 1907, the Second Peace Conference met at the Hague andproduced thirteen conventions.179 Again, agreement on laws of land warfareproved relatively easy to conclude. Conference delegates seemed content to

173. One author offers competing motives for the Czar’s initiation of the Conference. James L. Tryon,The Hague Conferences, 20 YALE L. J. 470, 471 (1911). The Czar’s father, who had initiated both the St.Petersburg and Brussels Conferences is said while on his deathbed to have charged his son to promote thepeace of the world. Id. An alternative, and more pragmatic motivation, may have been the Czar’s desireto mitigate the costly arms races of the period. Id. at 471–72.

174. Id. at 473.175. Report of Captain Crozier to the Commission of the United States of America to the Interna-

tional Conference at the Hague, Regarding the Work of the Second Sub-committee of the Second Com-mittee of the Conference, in 2 JAMES B. SCOTT, THE HAGUE PEACE CONFERENCES OF 1899 AND 1907, at45–46 (1909) [hereinafter RECORD HAGUE PEACE CONFERENCES].

176. 1899 Hague Convention (II) Respecting the Laws and Customs of War on Land with Annex ofRegulations, July 29, 1899, 32 Stat. 1803, 1 Bevans 247 [hereinafter 1899 Hague Convention II].

177. Id.178. Tryon, supra note 173, at 478. Although President Theodore Roosevelt took the first steps to R

initiate the Second Conference, he left the formalities of invitation again to Czar Nicholas II of Russia. Id.179. Convention for the Pacific Settlement of International Disputes, Oct. 18, 1907, 36 Stat. 2199, 1

Bevans 577 [hereinafter 1907 Hague Convention I]; Convention Respecting the Limitation of the Em-ployment of Force for the Recovery of Contract Debts, Oct. 18, 1907, 36 Stat. 2241, 1 Bevans 607[hereinafter 1907 Hague Convention II]; Convention Relative to the Opening of Hostilities, Oct. 18,1907, 36 Stat. 2259, 1 Bevans 619 [hereinafter 1907 Hague Convention III]; Convention Respecting theLaws and Customs of War on Land, Oct. 18, 1907, 36 Stat. 2277, 1 Bevans 631 [hereinafter 1907 HagueConvention IV]; Convention Respecting the Rights and Duties of Neutral Powers and Persons in Case ofWar on Land, Oct. 18, 1907, 36 Stat. 2310, 1 Bevans 654 [hereinafter 1907 Hague Convention V];Convention Relating to the Status of Enemy Merchant Ships at the Outbreak of Hostilities, Oct. 18,1907, 205 Consol. T.S. 305, 3 Martens Nouveau Recueil (ser. 3) [hereinafter 1907 Hague ConventionVI]; Convention Relating to the Conversion of Merchant Ships into War-Ships, Oct. 18, 1907, 205Consol. T.S. 319, 3 Martens Nouveau Recueil (ser. 3) 557 [hereinafter 1907 Hague Convention VII];Convention Relative to the Laying of Automatic Submarine Contact Mines, Oct. 18, 1907, 36 Stat.2332, 1 Bevans 669 [hereinafter 1907 Hague Convention VIII]; Convention Concerning Bombardmentby Naval Forces in Time of War, Oct. 18, 1907, 36 Stat. 2351, 1 Bevans 681 [hereinafter 1907 HagueConvention IX]; Convention for the Adaption to Maritime War of the Principles of the Geneva Conven-tion, Oct. 18, 1907, 36 Stat. 2371, 3 Martens Nouveau Recueil (ser. 3) 360 [hereinafter 1907 HagueConvention X]; Convention Relative to Certain Restrictions with Regard to the Exercise of the Right ofCapture in Naval War, Oct. 18, 1907, 36 Stat. 2396, 1 Bevans 711 [hereinafter 1907 Hague ConventionXI]; Convention Relative to the Creation of an International Prize Court, Oct. 18, 1907, 205 Consol.T.S. 381; Convention Concerning the Rights and Duties of Neutral Powers in Naval War, Oct. 18,1907, 205 Consol. T.S. 395, 1 Bevans 723 [hereinafter 1907 Hague Convention XIII].



reproduce in large part the work of the drafting efforts at Brussels and Ox-ford. The Fourth Hague Convention of 1907180 reproduced, with only slightvariations, the work of the 1899 Conference’s Second Convention, includingthe regulations contained in the appendix.181

Like its successful predecessors the Lieber Code and the St. PetersburgDeclaration, the Fourth Hague Convention included an explicit reference toreciprocity. Article 2 of the Convention provided the clearest possible condi-tion of obligational reciprocity, stating, “The provisions contained in theRegulations referred to in Article 1, as well as in the present Convention, donot apply except between Contracting powers, and then only if all the bel-ligerents are parties to the Convention.”182 The clausula si omnes, or generalparticipation clause, thus ensured that the Convention would operate exclu-sively between Treaty parties. In the plenary session that reviewed the provi-sion, Louis Renault, a law professor attached to the French delegation to the1899 Conference, remarked that article 2 “merely sanctions the commonlaw in the matter of the binding effect of the Regulations.”183 He also notedthe appearance of the clause in the earlier St. Petersburg Declaration.184 At alater review, Russian delegate Fyodor de Martens, who would lend his nameto the Convention’s famous preamble,185 strongly defended the si omnesclause as evidence of “a ‘mutual insurance association against the abuse doneof force in time of war,’ an association which states should be free to enter ornot, but which must have its own by-laws obligatory upon the membersamong themselves.” 186

The nature of the other twelve conventions produced at the 1907 HagueConference is consistent with the parties’ inclusion of the si omnes clause.Even the effort to extend the 1864 Geneva Convention to maritime settings,a treaty of an essentially humanitarian nature, was made subject to a si omnesclause.187 Most of the thirteen 1907 Hague Conventions reflected innova-tions in international law.188 Without customary status, states subjectedmany of the Hague Conventions to harsh conditions of obligational reciproc-

180. 1907 Hague Convention IV, supra note 179. R181. Tryon, supra note 173, at 481. Schindler & Toman provide a useful side-by-side printing of the R

1899 and 1907 Hague Conventions. SCHINDLER & TOMAN, supra note 137, at 64–98. R182. 1907 Hague Convention IV, supra note 187, art. 2. Recall that the St. Petersburg Declaration

included a nearly identical general participation clause. See supra text accompanying note 176.183. RECORD OF HAGUE PEACE CONFERENCES, supra note 175, at 209. R184. Id.185. See infra text accompanying notes 201–05. R186. RECORD OF HAGUE PEACE CONFERENCES, supra note 175, at 417 (emphasis in original). R187. See id. at 210. Article 18 of the Hague Convention X states, “The provisions of the present

Convention do not apply except between Contracting Powers, and only if all the belligerents are partiesto the Convention.” 1907 Hague Convention X, supra note 179, art. 18. States adopted Article 18 Rwithout discussion at the Plenary Conference of 1899. See id. at 210–11.

188. Report of the Swedish International Humanitarian Law Committee Stockholm 1984, reprinted in HOW

DOES LAW PROTECT IN WAR? 599 (Marco Sassoli & Antoine Bouvier eds., 1999).



ity. In fact, First World War belligerents rejected operation of a number ofthese instruments because their enemies had failed to ratify them.189

2. The Status of the Conventions: Custom or Innovation?

Uncertainty about whether the Conventions reflected custom when theywere signed led parties to object to their application on the grounds of bothobligational and observational reciprocity. The Convention’s preamble indi-cates an effort at innovation, stating an intention “to revise the general lawsand customs of war, either with a view to defining them with greater preci-sion or to confining them within such limits as would mitigate their sever-ity as far as possible . . . .”190 Yet, because so many of the Regulations drewtheir provisions from existing sources, some authorities have concluded thatthey reflected preexisting custom.191 Further, the relatively widespread rati-fication of the Fourth Conventions and its regulations may suggest custom-ary status.192

If the Regulations merely reflected custom, the parties’ insistence on thesi omnes clause would be curious. The clause would be largely superfluous ifstates intended to condition duties arising under the Convention on obliga-tional reciprocity when those same provisions were already universally appli-cable as a matter of custom. It is of course possible that the Convention andits Regulations matured into custom in the few years between 1907 and theFirst World War.193 However, there is insufficient state practice to supportsuch a claim.194 It is more plausible that some portions of the Regulations

189. COLEMAN PHILLIPSON, INTERNATIONAL LAW AND THE GREAT WAR 175 (1915) (noting Germanrejection of binding force of Hague Convention IX because not all belligerents ratified the Convention).Similarly, Dr. Phillipson dismissed the legal effect of British and Belgian agreement to prohibit launch-ing explosives and projectiles from aircraft, because other major powers, including Germany, had notratified the declaration. Id. at 176.

190. 1907 Hague Convention IV, supra note 179, pmbl. (emphasis added). R191. PHILLIPSON, supra note 189, at 158; W. Hays Parks, Air War and the Law of War, 32 AIR FORCE R

L. REV. 1, 14 (1990) (citing 1 J. SCOTT, THE HAGUE PEACE CONFERENCES OF 1899 AND 1907, at 537(1939) for the proposition that Articles 25 and 27 of the Hague Regulations reflected custom at the timeof drafting) [hereinafter Parks, Air War].

192. A contemporary source noted that “44 of the 47 states now commonly recognized as belongingto the family of civilized nations” met at the Second Conference. Tryon, supra note 173, at 478. Forty- Rone states signed the Hague Convention IV. See DOCUMENTS ON THE LAWS OF WAR, supra note 136, at R84–85. By 1914, twenty-seven states had ratified the Convention. Id.

193. Ian Brownlie notes that no formal duration of practice is required for the formation of custom.BROWNLIE, supra note 88, at 5. It seems that a notable intensity of practice might compensate for a short Rduration.

194. Although Article 1 of the Convention required parties to issue instructions to their armed forcesin conformity with the Regulations, few states complied. Hersch Lauterpacht offers a survey of theRegulations’ status under the municipal law of a number of states between the world wars. HerschLauterpacht, The Law of Nations and Punishment of War Crimes, 21 BRIT. Y.B. INT’L L. 58, 64 (1944)[hereinafter Lauterpacht, War Crimes]. Lauterpacht relates the interesting story of a German Majorcharged with preparing a 1901 Army Manual entitled “Customs of War on Land.” Id. at 64 n.1. TheManual contained no reference to the Hague Regulations. Id. When questioned on the omission by aReichstag Commission on War Crimes, the Major replied that he “had no detailed knowledge of theHague Regulations at the time.” Id. (citing 1 VOLKERRECHT IM WELTKRIEG 27).



reflected custom, whereas others had not garnered sufficient state practiceand acceptance to attain customary status prior to or during the War.

The Hague Regulations had a mixed record in the First World War.States applied the Regulations inconsistently, often claiming that other par-ties failed to respect both obligational and observational reciprocity. For in-stance, German newspapers cited the si omnes clause to justify Germany’snon-application of the Hague Regulations.195 German authorities invokednegative reciprocity in response to allegations of atrocities in Belgium andFrance.196 French authorities claimed that Germany’s breach had terminatedapplication of the Hague Regulations to their mutual relations.197 Assessingthe Regulations’ bombardment provisions, Geoffrey Best argues that theHague Regulations may have been far more effective as opportunities forstates to vilify their enemies rather than as limits on states’ conduct inwar.198 Best maintains that citations to the Hague Regulations often merelyshowcased how the enemy had treacherously reneged on its very recent legalcommitments.199 W. Hays Parks, a U.S. Department of Defense expert onthe law of war, notes that the reciprocal nature of Hague protections forcivilians marginalizes targeting restraints.200

Whether or not the Hague Regulations reflected custom at the time theywere signed, the Fourth Hague Convention acknowledged the role of cus-tom as a fixture in law of war treaties. The Martens Clause appears in theConvention’s preamble, stating:

Until a more complete code of the laws of war has been issued, thehigh contracting Parties deem it expedient to declare that, incases not included in the Regulations adopted by them, the in-habitants and the belligerents remain under the protection andthe rule of the principles of the law of nations, as they result from

195. PHILLIPSON, supra note 189, at 158 (citing reports in the COLOGNE GAZETTE). Phillipson rejects Rthe assertion that entry of non-Parties Serbia, Montenegro, and Turkey negated application of the HagueRegulations. Id. Phillipson concedes that had the Regulations been novel or concerned minor details, the“technical defence” offered by the general participation clause might have been acceptable. Id. at 158,176. However, he maintains that the Hague Regulations codified the preexisting custom, denying effectto the general participation clause. Id. Later, Phillipson renews his argument concerning the customarystatus of the Hague Conventions with respect to the prohibition on bombardment of undefended placesin the Article 25. Id. at 175–76. As observed earlier, Phillipson’s observation on the customary status ofthe Hague Conventions appears restricted to the Hague Convention IV. See supra text accompanying note189. R

196. PHILLIPSON, supra note 189, at 177. R197. RENE PROVOST, INTERNATIONAL HUMAN RIGHTS AND HUMANITARIAN LAW 172 n.73 (2000)

(citing Conseil de guerre de Paris (4e), Jun. 18 1919, 46 J. DU DROIT INT’L (CLUNET) 737, 740 (1919)).198. BEST, LAW AND WAR, supra note 127, at 47. R199. Id. at 47.200. Parks, Air War, supra note 191, at 15. Parks notes that Article 27 of the Annexed Regulations to R

the Hague Conventions requires protection of hospitals, museums, and schools so long as they are notused for military purposes. Id.



the usages established among civilized peoples, from the laws ofhumanity, and the dictates of public conscience.201

The Martens Clause emerged from unresolved debate over the rights of in-habitants of occupied territory to resist their occupiers.202 Small states, whowould be forced to rely on “unconventional” means of resistance in case ofinvasion, objected to limits on rights of popular resistance proposed by morepowerful states. The Martens Clause resolved the impasse over treatment ofresistance fighters by referring to the common law of war and to more gen-eral norms of humane treatment.

Several conclusions flow from the Clause. First, the Martens Clause con-cedes the incomplete nature of the Hague Regulations. The drafters wereaware of the limitations their political interests placed on any agreementcodifying war rules. The Clause denies that the new, positive law of warwould operate in an exclusive fashion, clearly anticipating that customarynorms would supplement the Hague Regulations during war. Second, theMartens Clause evidences the broad applicability of some customary norms.The Clause explicitly acknowledges the Regulations’ limits on applicability,specifically mentioning the si omnes clause.203 However, the Clause also re-minds parties that failure to achieve conditions for treaty application doesnot give rise to lawlessness.

While certainly advancing humanitarian considerations, the MartensClause reiterates the shortcomings of custom. That the Clause arose as acompromise to intractable debate over substantive provisions of the law ofwar reveals the unsettled nature of the customary constraints on war.204 TheClause suggests that many constraints could only be expressed in thebroadest and most general terms—as principles rather than detailed provi-sions. Furthermore, although identification of universally applicable cus-toms would go a long way toward overcoming the requirement ofobligational reciprocity, one wonders whether states at the time would inpractice have adhered to such norms in the face of persistent objection orviolation by an enemy.205

201. 1907 Hague Convention IV, supra note 179, pmbl.; 1899 Hague Convention II, supra note 176, Rpmbl.

202. See DOCUMENTS ON THE LAWS OF WAR, supra note 136, at 9 (citing Ministere des Affaires REtrangeres, Report of the Second Subcommission in the official report, Conference Internationale de la Paix,La Haye, 18 Mai–29 Juillet 1899, Imprimerie Nationale, The Hague, 1899, 49–51; WILLIAM I. HULL,THE TWO HAGUE CONFERENCES AND THEIR CONTRIBUTIONS TO INTERNATIONAL LAW 215–20 (1908)).

203. The passage immediately following the Clause reads, “They declare that it is in this sense espe-cially that Articles 1 and 2 of the Regulations adopted must be understood.” 1907 Hague ConventionIV, supra note 179, pmbl.; 1899 Hague Convention II, supra note 176, pmbl. R

204. See supra text accompanying note 202. R205. See infra discussion accompanying note 210 (discussing retaliatory attacks on civilian population R

centers in the Second World War).



3. The Hague Conventions in Practice, 1907 to 1949

State practice from the First World War through the Second World Warreveals the practical limitations of the Hague Conventions. Indeed, theatrocities committed during this era cast doubt on whether the Conventionshad any impact on state behavior. Failure to convene meaningful post-con-flict war crimes tribunals likely retarded authoritative, neutral, or indepen-dent interpretation of the Martens Clause and the Hague Regulationsgenerally. Although the otherwise draconian Versailles Treaty provided forthe transfer and international trial of war criminals, these provisions werenever enforced.206 Only a handful of German domestic trials were ever con-ducted.207 The Leipzig Trials, conducted by the German government againstits own soldiers, did not include significant analysis of the Hague Regula-tions’ applicability, the state of customary laws of war, or of the legitimacyof exercising negative reciprocity.208

The inter-war period also shed little light on the status of the HagueConvention.209 Only two states acceded to the Convention between 1919and 1939—Poland, in 1925, and Ethiopia in 1935, the latter on the eve ofbeing invaded by Italy for the second time in less than fifty years.210 Italyhad signed but had not ratified the Fourth Hague Convention. The SecondItalo-Ethiopian (or Abyssinian) War involved infamous atrocities, includingmaltreatment of prisoners, attacks on Red Cross facilities and hospitals, andthe use of poisonous gas. The states were entreated to observe the 1864

206. Treaty of Versailles arts. 228–30, June 28, 1919, 13 A.J.I.L. Supp. 151, 385, 2 Bevans 235.German international law scholars objected strongly to the Treaty’s transfer and prosecution provisions.See Lauterpacht, War Crimes, supra note 194, at 61. A German Privy Councillor, responding to a request Rfor legal review from the German Reichstag, observed, “The Allies [have] imposed upon Germany abreach of most elementary legal principles and a forced departure from entire German legal history.” Id.(quoting 3 VOLKERRECHT IM WELTKRIEG 57).

Lauterpacht also considers the interesting reciprocity-based question of whether absence of mutualityconcerning prosecution of war crimes between victors and defeated powers undermines the legitimacy ofthe former. Lauterpacht, War Crimes, supra note 194, at 68. He concedes the apparent inequity and offers Raspirations, yet little more, for a more equitable post-war system of prosecutions, including the possibil-ity of an International Criminal Court. Id. at 68, 82.

207. See generally CLAUD MULLINS, THE LEIPZIG TRIALS (1921).208. Id.209. Some regard the inter-war period as a dark age of sorts for development of the law of war. See

J.W. Garner, The Outlook for the Law of War and of Neutrality, in 22 TRANSACTIONS OF THE GROTIUS

SOCIETY 1 (1937). Professor Garner observes of the period, “Many persons spoke of [the law of war] moreor less contemptuously as the ‘so-called’ law of war. . . . University professors dropped the subject fromtheir course, and even text writers omitted it from their books . . . .” Id.

210. Italy was not party to the Hague Conventions, and the tactics it employed in the 1935 to 1936conflict repulsed countries around the world. “The employment of gas in Ethiopia was roundly con-demned and the world recoiled with horror when reports of systematic attacks on Red Cross units byItalian aircraft began to reach Europe.” A.J. BARKER, THE CIVILIZING MISSION: A HISTORY OF THE

ITALO-ETHIOPIAN WAR OF 1935–1936, at 243 (1968). Italy had ratified the 1925 Protocol for theProhibition of the Use in War of Asphyxiating, Poisonous or other Gases, and of Bacteriological Methodsof Warfare, and 750 Italians were charged with war crimes as a result of the atrocities committed in thewar. M. Cherif Bassiouni, From Versailles to Rwanda in Seventy-Five Years: The Need to Establish a PermanentInternational Criminal Court, 10 HARV. HUM. RTS. J. 11, 30 (1997).



Geneva Convention, to which they were both parties,211 but research revealslittle discussion of the Hague Regulations as having binding force as customor as the foundation for establishing war crimes. Indeed, the law of warappears to have existed within an especially “chaotic state” during this pe-riod, prompting commentators to speculate that future war would be con-ducted under very uncertain rules.212

The Second World War resurrected questions about the effect of theHague Conventions’ si omnes clause and obligational reciprocity generally. Anumber of parties to the conflict, including Bulgaria, Greece, Italy, and Yu-goslavia, had not acceded to the Hague Conventions. However, war crimestribunals in the post-war era, including the Nuremberg International Mili-tary Tribunal (“IMT”), rejected the clause as a defense to crimes based onviolations of the Regulations.213 The IMT’s conclusions regarding the Con-vention and Regulations’ status as customary law essentially rendered the siomnes clause a dead letter. The IMT’s recognition of the Hague Regulations’provisions as customary obligations ran contrary to states’ insistence thatvarious conditions restricted their application. Accepting the IMT’s conclu-sions requires a fragmentation of the Convention. That is, the IMT’s assign-ment of customary status divorced the substantive Regulations from theirclear textual conditions on application. Until the Second World War, stateshad not evinced any willingness to accept the Regulations’ constraints inde-pendent of formal obligational reciprocity. As late as 1994, governmentsresorted to the si omnes clause in their analyses of the applicability of theHague Regulations. For instance, the German Federal Government repliedto inquiries submitted by a member of its Lower House of Parliament con-cerning application of the Hague Regulations to the armed conflict between

211. See Bernard Bridel, Les ambulances a croix rouge du CICR sous les gaz en Ethiopie, LE TEMPS (Aug. 13,2003), translated and reproduced at http://www.icrc.org/Web/eng/siteeng0.nsf/iwpList96/DEB07F09BE30F4B8C1256DB000479398> (describing ICRC reports of atrocities committed by both parties to theconflict).

212. Garner, supra note 209, at 5. R213. George H. Aldrich & Christine M. Chinkin, The Hague Peace Conferences: A Century Of Achievement

And Unfinished Work, 94 AM. J. INT’L L. 90, 93 (2000) (“For example, the relevant provisions of the 1899and 1907 Hague Conventions on the Laws and Customs of War on Land became accepted in practice sothat, by 1945, the international tribunal trying Germans accused of war crimes was able to hold thatHague Convention No. IV and its annexed Regulations had become part of customary international lawbinding on Germany, even though the Convention as such was not applicable to the Second WorldWar.”) (citing United States v. Von Leeb [High Command Case], in 11 TRIALS OF WAR CRIMINALS

BEFORE THE NUREMBERG MILITARY TRIBUNAL UNDER CONTROL COUNCIL LAW NO. 10, at 462 (1950));see also OPPENHEIM’S INTERNATIONAL LAW 234–36 (Hersch Lauterpacht ed., 7th ed. 1952).

The Nuremberg Military Tribunal declared the Hague Regulations to be customary law: “The rules ofland warfare expressed in the Convention undoubtedly represented an advance over existing internationallaw at the time of their adoption. But the Convention expressly stated that it was an attempt ‘to revisethe general laws and customs of war,’ which it thus recognized to be then existing, but by 1939 theserules laid down in the Convention were recognized by all civilized nations, and were regarded as beingdeclaratory of the laws and customs of war which are referred to in Article 6(b) of the Charter.” Id. at 51(quoting Trial of German Major War Criminals, 22:467).



the Government of Turkey and the PKK by noting that Turkey had notratified the Fourth Hague Convention.214

The vitality of observational reciprocity under the Convention and Regu-lations during the Second World War is similarly uncertain. The scope andscale of violations of purportedly settled restraints on war were truly shock-ing. Widespread, indiscriminate bombing and deplorable treatment of pris-oners of war on both sides of the conflict flouted the spirit of prohibitionscontained in the Hague Regulations. In the first edition of his update toOppenheim’s international law treatise after the Second World War, HerschLauterpacht observed that the law of war “never before in history was sowidely and so ruthlessly disregarded as in the Second World War.”215 Thehistorian Michael Howard concluded that the War marked the “beginningof the end of what we have called the Grotian era,” wherein it had beenthought that “an assumption of common values . . . would govern the con-duct of . . . wars, whether or not these values were codified.”216 In fact,during the war, neutral governmental pleas for restraint in the conduct ofhostilities provoked reiteration of the condition of observational reciprocityfrom both sides of the conflict.217

State claims and reservations notwithstanding, the IMT weighed instrongly against rights of negative reciprocity, as illustrated by its rejectionof the tu quoque defense.218 Charged with, inter alia, violating rules for theuse of submarines against merchant shipping,219 the former German Chief ofNaval Operations, Admiral Karl Donitz argued that mutual breach had sus-

214. BTDrucks 12/8458, translated in Sassoli & Bouvier, supra note 188, at 1384–85. Ultimately, the Rresponse determined that Common Article 3 of the 1949 Geneva Conventions set the minimum legalstandards applicable to the conflict. Id. at 1385. The response noted that the parties might augmentArticle 3 by agreeing to undertake further legal obligations through Article 96(3) of Additional ProtocolI. Id.

215. OPPENHEIM 2, supra note 99, at iii. R216. Michael Howard, Constraints on Warfare, in THE LAWS OF WAR, supra note 124, at 7–8. R217. See Tami Davis Biddle, Air Power, in THE LAWS OF WAR, supra note 124, at 151. Biddle notes R

that “[r]esponding in 1939 to a plea by President Roosevelt, Germany, England, and France agreed tolimit bombing to strictly military objectives at the outset of the war. But all three powers reserved theright to take appropriate action in the event that their enemies reneged.” Id.

218. Tu quoque, translated as “you also,” offers a defense in situations of mutual breach. Sienho Yee,The Tu Quoque Argument as a Defence to International Crimes, Prosecution or Punishment, 3 CHINESE J. INT’L L.87, 87 (2004). Albin Eser describes tu quoque as an argument allowing “the commission of an interna-tional crime simply because of the fact that the adversary is behaving in the same (reprehensible) way.”Albin Eser, Defences in War Crimes Trials, in WAR CRIMES IN INTERNATIONAL LAW 251, 269 (YoramDinstein ed., 1996); see also Brad R. Roth, Just Short of Torture: Abusive Treatment and the Limits of Interna-tional Criminal Justice, 6 J. INT’L CRIM. JUST. 215, 232 (2008) (detailing the implications of tu quoque asa defense to international criminal behavior).

219. See Proces-Verbal Relating to the Rules of Submarine Warfare Set Forth in Part IV of the Treatyof London of 22 April 1930, Nov. 6, 1936, 173 L.N.T.S. 353, reprinted in SCHINDLER & TOMAN, supranote 137, at 1145. The charges against Donitz are available in the trial records of the Nuremberg RInternational Military Tribunals. See 22 TRIAL OF THE MAJOR WAR CRIMINALS BEFORE THE INTERNA-

TIONAL MILITARY TRIBUNAL 557 (1949).



pended the rules.220 Donitz’s defense offered responses to an interrogatoryfrom U.S. Fleet Admiral Chester Nimitz, who confirmed that U.S. subma-rine forces had also disregarded the submarine rules in the Pacific theater.221

The IMT rejected Donitz’s defense, concluding that, despite mutual breach,the rules remained in effect. Although the IMT convicted Donitz, it deniedtaking account of the submarine violations during sentencing.222 As withobligational reciprocity, the IMT proved willing to read conditions of obser-vational reciprocity out of the law of war in the face of compelling evidenceof state practice to the contrary.223 The IMT Prosecutor, however, declinedto prepare indictments based on the targeting provisions of the 1907 HagueRegulations. Telford Taylor, the Chief Counsel for the IMT, related after thetrial:

Many of the provisions of the Hague Conventions regarding un-lawful means of combat . . . were antiquarian. Others had beenobserved only partially during the First World War and almostcompletely disregarded during the Second World War . . . . Theindictment of the first Nuremberg trial, accordingly, contained

220. See 17 TRIAL OF THE MAJOR WAR CRIMINALS BEFORE THE INTERNATIONAL MILITARY TRIBUNAL

378–81 (1949); see also 40 TRIAL OF THE MAJOR WAR CRIMINALS BEFORE THE INTERNATIONAL MILITARY

TRIBUNAL 108–11.221. 13 TRIAL OF THE MAJOR WAR CRIMINALS BEFORE THE INTERNATIONAL MILITARY TRIBUNAL

347.222. 22 Nuremberg IMT, supra note 219, at 559. The Tribunal sentenced Admiral Donitz to ten R

years’ imprisonment. Id. at 588. For his part, Donitz expressed no regret over his conduct of the subma-rine campaign. In his final statement to the Tribunal, Donitz stated, “I consider this form of warfarejustified and have acted according to my conscience. I would have to do exactly the same all over again.”Id. at 390.

223. War crimes trials conducted by national military tribunals mirrored some conclusions of theNuremberg International Military Tribunal. See United States v.Von Leeb, in 12 TRIALS OF WAR

CRIMINALS BEFORE THE NUREMBERG MILITARY TRIBUNALS UNDER CONTROL COUNCIL LAW 532–33(1951) [hereinafter The High Command Trial]; United States v. Ernst von Weizsaecker, in 14 TRIALS OF

WAR CRIMINALS BEFORE THE NUREMBERG MILITARY TRIBUNALS UNDER CONTROL COUNCIL LAW 323(1951) [hereinafter The Ministries Case]. In the High Command Trial, Field Marshal von Leeb’s final state-ment recounted a failure of reciprocal observance of the law of war on the Eastern Front. Von Leeb stated:

In the East the grim aspect of the war was determined by Russia. Stalin’s appeal for theslaughter of all Germans induced the partisans to pervert the conduct of the war. We, asGerman soldiers, had up to that moment refrained from such conduct, and we had not desiredand sought such extremes; neither in Russia nor in other theaters. We were forced to seekeffective protection against this degeneration in warfare. We acted in self-defense.

The High Command Trial, supra at 459–60. In The Ministries Case, the Nuremberg International MilitaryTribunal addressed charges stemming from the murder upon recapture of fifty escaped British Prisonersof War from Stalag Luft III, an event dramatized in the Steve McQueen film The Great Escape and anumber of memoirs. See generally WILLIAM ASH, UNDER THE WIRE (2005); PAUL BRICKHILL, THE GREAT

ESCAPE (1950); ALAN BURGESS, THE LONGEST TUNNEL (1991); ALBERT P. CLARK, 33 MONTHS AS A

POW IN STALAG LUFT III (2005). The Nuremberg International Military Tribunal noted a GermanForeign Office response to Swiss inquiries on behalf of the British prisoners wherein the German ForeignOffice asserted that because of its bombing of the German civilian population the British “must bedenied the moral right to take a stand in the matter of the escapees or to raise complaints against others.”The Ministries Case, supra at 456–57. The Nuremberg International Military Tribunal dismissed the de-fendants’ assertion of suspension of the Geneva Conventions or the Hague Regulations. Id. at 461.



no charges against the defendants arising out of their conduct ofthe war in the air.224

States continued the work of the Hague tradition at a number of treatyconferences throughout the interwar years.225 The 1925 Geneva Gas Proto-col illustrates prevailing state views on reciprocity and issues associated withthe Hague Tradition.226 The Protocol opens with an aspirational preambleurging universal acceptance and practice of its ban on the use of asphyxiat-ing gases.227 The goal of universal observance seemed reasonable given thatthe Protocol built off the work of the First Hague Conference’s DeclarationII, which prohibited the use of projectiles to deploy “deleterious gases.”228

The fact that Declaration II was thought to have merely codified preexistingcustom against the use of poison and treacherous weapons may also havebolstered optimism about widespread observance.229 Putative customary sta-tus notwithstanding, states’ delegates to the drafting convention attemptedto condition treaty obligations on reciprocity by inserting a si omnesclause.230 While other delegates fended off the inclusion of reciprocity in thetreaty text, major powers ratified the Protocol only with reservations to thateffect. For instance, the Government of France submitted the followingreservations:

The said Protocol is only binding on the Government of theFrench Republic as regards States which have signed or ratified itor which may accede to it.

The said Protocol shall ipso facto cease to be binding on theGovernment of the French Republic in regard to any enemy State

224. See Parks, supra note 191, at 37–38 (quoting TELFORD TAYLOR, FINAL REPORT TO THE SECRE- RTARY OF THE ARMY ON THE NUERENBERG WAR CRIMES TRIALS UNDER CONTROL COUNCIL LAW NO.10, at 65 (1949)).

225. See, e.g., Treaty for the Limitation and Reduction of Naval Armaments, Dec. 31, 1930, 112L.N.T.S. 65; Commision of Jurists to Consider and Report upon the Revision of the Rulse of Warfare,Rules of Aerial Warfare, opened for signature Feb. 26 1923, 32 A.J.I.L. Supp. 1, 12, 34.

226. Geneva Protocol for the Prohibition on the Use in War of Asphyxiating Poisonous or OtherGases, and of Bacteriological Methods in Warfare, June 17, 1925, 26 U.S.T. 571, T.I.A.S. No. 8061, 94L.N.T.S. 65 [hereinafter 1925 Gas Protocol]. The 1925 Gas Protocol remains in force and has 135 statesparties. See International Committee of the Red Cross, State Parties to the Following International Hu-manitarian Law and Other Related Treaties as of 6-MAR-2009, http://www.icrc.org/IHL.nsf/(SPF)/party_main_treaties/$File/IHL_and_other_related_Treaties.pdf (last visited Mar. 13, 2009). However,the 1925 Gas Protocol has been supplemented and amended by the 1993 Chemical Weapons Conven-tion. See Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemi-cal Weapons and on their Destruction, Jan. 13, 1993, 1974 U.N.T.S. 45, S. Treaty Doc. No. 103–21[hereinafter CWC].

227. 1925 Gas Protocol, supra note 226, pmbl. R228. Hague Convention IV, Declaration II Concerning the Prohibition of the Use of Projectiles Dif-

fusing Asphyxiating Gases, July 29, 1899, 187 Consol. T.S. 453, 26 Martens Nouveau Recueil (ser. 2)998, reprinted in DOCUMENTS ON THE LAWS OF WAR, supra note 136, at 60–61. R

229. See DOCUMENTS ON THE LAWS OF WAR, supra note 136, at 59, 155. R230. Proceedings of the Conference for the Supervision of the International Trade in Arms and Am-

munition and in Implements of War, League of Nations Doc. A13.1925.IX (1925).



whose armed forces or whose Allies fail to respect the prohibitionslaid down in the Protocol.231

The Soviet Union, Czechoslovakia, Great Britain, and the Netherlands repli-cated France’s reservations.232 Germany similarly declared that it would ob-serve the 1925 Protocol subject to reciprocity.233 The reservations managedto address both obligational and observational reciprocity. In the first clauseof the reservation, states parties to the Gas Protocol resurrected the reciproc-ity-based conditions that appeared in the Hague Regulations’ si omnesclause.234 In the second, they reserved the right to exercise negative reciproc-ity in response to the use of chemical weapons. Again, the states’ reserva-tions are curious considering that the prohibition on the use of asphyxiatinggases was thought to be a customary norm. The most likely explanation isthat the form and content of whatever customary rule existed did not, in theopinion of states, match the Protocol in scope or content. Additionally, the1925 Geneva Gas Protocol reservations may indicate that such customarynorms were also subject to conditions of at least observational reciprocity.235

More generally, however, the Protocol’s reservations evince that states re-garded customary norms as fully subject to both obligational and observa-tional reciprocity.

Law of war historian Geoffrey Best has characterized most inter-war legaldevelopments as window dressing.236 In these fledgling efforts to forge in-ternational agreements on the law of war, obligational reciprocity cabinedthe limits on the conduct of hostilities. Although judicial bodies rejecteddefendants’ arguments that legal norms were suspended under negative reci-procity, states were unwilling to codify limits on negative reciprocity, pre-

231. See DOCUMENTS ON THE LAWS OF WAR, supra note 136, at 165 (emphasis added). R232. Reservations withdrawn in later years. See infra discussion accompanying note 234. The United R

States did not ratify the 1925 Gas Protocol until 1975. Though transmitted to the U.S. Senate for adviceand consent in 1926, Senator William Borah, Chairman of the Foreign Relations Committee unexpect-edly withheld the Protocol from a vote. R.R. Baxter & Thomas Buergenthal, Legal Aspects of the GenevaProtocol of 1925, 64 AM. J. INT’L L. 853, 855 n.11 (1970). In 1947, President Truman withdrew thetreaty from consideration. Id.

233. DOCUMENTS ON THE LAWS OF WAR, supra note 136, at 156. R234. By the mid 1990s, many states, including France, withdrew their reciprocity-based reservations

to the 1925 Gas Protocol. For a complete catalog of reservations and withdrawals to the 1925 GasProtocol, see DOCUMENTS ON THE LAWS OF WAR, supra note 136, at 164–67. The CWC supplements the R1925 Protocol’s regulation of the use of gas. The CWC includes no readily apparent conditions onapplication; for instance, the treaty makes no distinction between international and non-internationalarmed conflict. Parties to the CWC pledge in Article 1 “never under any circumstances” to develop, use,prepare to use or encourage others to use chemical weapons.” Id. art. 1. Furthermore, Article 22 of theCWC prohibits reservations to the treaty’s main body. Id. art. 22. Yet, the treaty’s withdrawal provisionsinclude what might be characterized as a nod to conditions of reciprocal observance under extreme condi-tions. Article 16 permits a state to withdraw with ninety days notice in the case of “extraordinary eventsit regards as having jeopardized its supreme interests.” Id. art. 16.

235. See supra discussion accompanying note 231. Japan, though it never ratified the treaty, was Rprosecuted for using gas against China.

236. BEST, supra note 127, at 46, 59. Best questions even his own earlier work’s conclusions regarding Rthe practical influence of the Hague Regulations. Id. at 46.



ferring to leave the doctrine to treaty reservations and the general customs oftreaty law. Indeed, there are few state commitments to unreciprocated obser-vance of the law of war from that period.

D. The 1949 Geneva Conventions

The 1949 Geneva Conventions237 represented one of the most significantlegal advances for humanitarian protections during war. Universally ratifiedand almost universally recognized, they have become synonymous with thelaw of war in the popular understanding. Although they continued the pre-existing Geneva Tradition of regulating the law of war,238 the 1949 Conven-tions were nothing less than revolutionary. First, although they built onprevious Geneva guarantees of protection for recognized classes of war vic-tims (the wounded and sick, the shipwrecked, and prisoners of war), the1949 Conventions originated a system of enforcement that none of theirpredecessors, including treaties of the Hague Tradition, had managed.239

Second, the 1949 Conventions explicitly addressed the treatment of victimsof armed conflict beyond the limited context of war between sovereigns.240

Finally, in recognition of their horrendous suffering in the Second WorldWar, the 1949 Conventions added civilians to the Geneva Tradition’s classesof protected persons.241

The Geneva revolution was not entirely successful. Although statesproved willing to expand protections and strengthen enforcement regimes,the Conventions were almost as conditional as previous instruments of theGeneva Tradition. Evidence of these conditions was subtle and often veiled.To be sure, the 1949 Conventions did not include a si omnes clause. TheConventions explicitly rejected non-parties’ entry into conflicts betweenstates parties as a basis for withholding application of the Conventionsamong parties.242 However, restrictions on the types of conflict to which

237. 1949 Geneva Convention I, supra note 155; 1949 Geneva Convention II, supra note 155; 1949 RGeneva Convention III, supra note 155; Geneva Convention IV, supra note 155. R

238. See sources cited supra note 172 (describing the Geneva and Hague Traditions as well as the Rlimits of these characterizations).

239. The Conventions are to be enforced primarily through a system identifying grave breaches: eachof the four Geneva Conventions includes two articles describing offenses punishable as grave breaches anddelineating a system of universal and compulsory jurisdiction for states parties. See, e.g., 1949 GenevaConvention IV, supra note 155, arts. 146, 147. R

240. See 1949 Geneva Convention I, supra note 155, art. 3; 1949 Geneva Convention II, supra note R155, art. 3; 1949 Geneva Convention III, supra note 155, art. 3; 1949 Geneva Convention IV, supra note R155, art. 3. R

241. The Fourth Geneva Convention’s provisions in Part II offer broad protections for civilians. See1949 Geneva Convention IV, supra note 155, Part II. The Fourth Convention’s Article 4 protects the Rnationals of parties who are in the enemies’ hands. Id. art. 4. Each of the Conventions protects civilians innon-international armed conflict through Common Article 3. See, e.g., 1949 Geneva Convention I, supranote 155, art. 3; 1949 Geneva Convention II, supra note 155, art. 3; 1949 Geneva Convention III, supra Rnote 155, art. 3; 1949 Geneva Convention IV, supra note 155, art. 3. R

242. See, e.g., 1949 Geneva Convention I, supra note 155, art. 2(3); 1949 Geneva Convention II, supra Rnote 155, art. 2(3); 1949 Geneva Convention III, supra note 155, art. 2(3); 1949 Geneva Convention IV, Rsupra note 155, art. 2(3). R



most of the Conventions applied and restrictions on the persons to whomthe Conventions gave their most elaborate protection qualified their cover-age in a manner similar to traditional reciprocity provisions.

A number of common misconceptions and exaggerations have grownaround the Conventions.243 The gravest of these misconceptions may be thatthe Geneva Conventions apply in their entirety to all cases of hostilities.States’ rejection of this notion at the diplomatic convention could not havebeen clearer. Since promulgating the 1864 Geneva Convention, the Interna-tional Committee of the Red Cross (“ICRC”) has been the de facto conven-ing authority for diplomatic conferences to revise instruments of the GenevaTradition. As at earlier conferences, the ICRC submitted a draft conventionto the states assembled in 1949.244 The most ambitious passage of the draftwould have applied the Conventions to all conflicts. Article 2 of the Stock-holm Draft would have made the Conventions applicable in their entiretynot only to armed conflict and belligerent occupation between states parties,but also to “armed conflict not of an international character which mayoccur in the territory of one or more of the High Contracting Parties.”245

Perhaps as an enticement to adopt this radical alteration of the scope of thelaw of war, the draft included an explicit and remarkable guarantee of nega-tive reciprocity. Draft Article 2, Section 4 read: “[E]ach of the Parties to theconflict shall be bound to implement the provisions of the present Conven-tion, subject to the adverse party likewise acting in obedience thereto.”246

The clause would have done for observational reciprocity what the si omnes

243. One of the most common misconceptions is that the Geneva Conventions still constitute a singleconvention. Strictly speaking, the term “the Geneva Convention” accurately describes only the 1864Geneva Convention. Each incarnation from the Geneva Tradition since 1864 has either supplementedthat Convention or taken the form of multiple Conventions emanating from the same DiplomaticConference.

244. The draft convention submitted to states’ representatives in Geneva in 1949 was known to theConference as the Stockholm Draft. The Stockholm Draft emerged from work on an earlier draft submit-ted to states at the 1948 17th International Red Cross Conference in Stockholm, Sweden. COMMENTARY,IV GENEVA CONVENTION RELATIVE TO THE PROTECTION OF CIVILIAN PERSONS IN TIME OF WAR 6–7(Jean S. Pictet ed., 1958) [hereinafter COMMENTARY, GENEVA CONVENTION IV].

245. Draft Convention for the Protection of Civilian Persons in Time of War, 1949, reprinted in 1FINAL RECORD OF THE DIPLOMATIC CONFERENCE OF GENEVA OF 1949, at 113 (William S. Hein & Co.2004) (1950) [hereinafter 1949 DIPLOMATIC RECORD].

The 1949 Diplomatic Record’s use of the term “in the territory of one or more of the High ContractingParties” is in contrast to the phrase adopted to describe the geographic reach of Common Article 3.Ultimately, states used the term “in the territory of one of the High Contracting Parties.” In 2002, thatadopted formulation led the U.S. Department of Justice Office of Legal Counsel (“OLC”) to concludethat Common Article 3 did not apply to international conflicts with non-state actors, such as the GlobalWar on Terror. See infra note 252 (describing in greater detail OLC’s analysis of Common Article 3). RThough not cited by OLC, the change cited above from the 1949 Diplomatic Record supports OLC’sotherwise controversial conclusion.

246. 1949 DIPLOMATIC RECORD, supra note 245. Norway objected early to the condition of reciproc- Rity in general and as running counter to the Conventions’ ban on reprisals against prisoners of war. 2BFINAL RECORD OF THE DIPLOMATIC CONFERENCE OF GENEVA OF 1949, at 41, 44 (William S. Hein & Co.2004) (1950) [hereinafter 2B 1949 DIPLOMATIC RECORD]. Likewise, the United States objected to thecondition of observational reciprocity in civil wars. See id. at 48. Italy preferred that reciprocity not be“dealt with specifically in the case of conflicts which were not dealt with of an international character.”



clause did for obligational reciprocity. Concessions to reciprocity notwith-standing, states rejected the proposal.247 Citing practical and legal concerns,states significantly narrowed the Draft Article’s scope of coverage in thefinal Convention.248

In their final version, only one of the Conventions’ nearly four hundredseparate articles applies to all cases of armed conflict—Common Article3.249 Common Article 3 is “common” only in the sense that it appears ineach of the four Conventions. Called a “Convention in miniature” by one ofthe delegates to the 1949 Geneva Conventions Diplomatic Conference,Common Article 3 outlines a minimum level of humanitarian protections insituations of armed conflict to which other conventional protections do notapply. Though textually committed to regulating “armed conflict not of aninternational character,” Common Article 3 is best understood in contradis-tinction to armed conflicts covered by the rest of the Conventions. As theU.S. Supreme Court recently affirmed, Common Article 3 is a minimumthreshold for armed conflicts and persons not qualifying for protection underthe full Conventions.250

The revolutionary nature of Common Article 3 lay neither in its self-contained format nor in the character of the protections it afforded. TheArticle eschews elaborate schemes of regulation, confining itself to thebroadest humanitarian principles. Common Article 3 was truly novel in itsfocus on states’ internal affairs and its application of international law to theconduct of civil wars. Common Article 3 constrains states’ treatment of theirown citizens who rebel or conduct organized hostilities251 within their own

Id. at 49. The Soviet Union remained committed to the original draft, including its condition of de factoreciprocal compliance with the Conventions as a precondition to application. Id. at 50.

247. A record of states’ discussions and ultimate rejection of the draft universal application provisionis available in 2B 1949 DIPLOMATIC RECORD, supra note 246, at 41–43. Among other conceptual con- Rcerns, the delegates noted that applying the Civilians Convention to insurgents would be problematic,because the Convention relied on the enemy’s nationality to define the protected person class. Id. at 41.The Delegation of the Soviet Union was the exception, championing the draft article’s expansion to covernon-international armed conflicts. See id. at 43. The Soviet Delegation’s apparently magnanimous andconfusingly liberal approach to revising the Conventions confounded and frustrated the delegations ofWestern powers during the Conference. See id. at 318–20, 380, 448–55.

248. A Soviet delegate remarked on debate concerning the scope of application of the Conventions,“No other issue has given rise to such a long discussion and to such a detailed and exhaustive study as thequestion of the extension of the Convention to war victims of conflicts not of an international character.”Id. at 325.

249. See, e.g., 1949 Geneva Convention I, supra note 155, art. 3; 1949 Geneva Convention II, supra Rnote 155, art. 3; 1949 Geneva Convention III, supra note 155, art. 3; 1949 Geneva Convention IV, supra Rnote 155, art. 3. R

250. Hamdan v. Rumsfeld, 548 U.S. 557, 629–31 (2006); see also ARMY JUDGE ADVOC. GEN. LEGAL

CENTER AND SCH., DEP’T OF THE ARMY, LAW OF WAR HANDBOOK 149 (Keith E. Puls ed., 2004)(stating that Common Article 3 “serves as a ‘minimum yardstick of protection in all conflicts, not justinternal armed conflicts’” (quoting Military and Paramilitary Activities (Nicar. v. U.S., 1986 I.C.J. 14,¶ 218 (June 27)))); Prosecutor v. Tadic, Case No. IT-94-1-I, Decision on the Defence Motion for Inter-locutory Appeal on Jurisdiction, ¶ 102 (Oct. 2, 1995) (stating that “the character of the conflict isirrelevant” in deciding whether Common Article 3 applies).

251. Jean Pictet’s Commentary to the 1949 Conventions discusses the requirement that rebel move-ments be organized to qualify for protection under Common Article 3. COMMENTARY, GENEVA CONVEN-



territories.252 As in the case of the Lieber Code’s application to the AmericanCivil War, states had previously applied humanitarian legal restraints tocivil war, yet Common Article 3 is remarkable as an international legal com-mitment to such restraint.253

The implications of Common Article 3 for the traditional principle ofreciprocity are potentially profound. As non-international armed conflicts donot entail interactions between states, the operation of Article 3 might beentirely free from conditions of mutual obligation. For example, a stateparty could not avoid Article 3 restrictions regarding its conduct in a civilwar merely by failing to ratify the Conventions. In this sense, CommonArticle 3 could be a truly unilateral international norm, rather than a bilat-eral or multilateral obligation subject to traditional privity of commitment.Common Article 3 may further limit traditional obligational reciprocity be-cause parties to the conflict may lack international legal character. Though arebel force may express commitment to Article 3 and its principles, it can-not ratify the Conventions. Common Article 3 does not grant internationallegal personality to individuals or rebel groups.254 Rather, it binds rebelforces when ratified by their sovereign opponents.255 Thus, formal, obliga-tional reciprocity between belligerents in a non-international armed conflictis not a precondition to the operation of Article 3.

Obligational reciprocity may persist in at least one regard with respect toCommon Article 3. As an international legal commitment rather than adomestically guaranteed right, Common Article 3 relies on the internationallegal system for enforcement.256 Although Article 3 encapsulates a number

TION IV, supra note 244, at 35–36. Jean Pictet served as a delegate of the ICRC at the 1949 Geneva RConventions Diplomatic Conference. Following the Conference and signature of the Conventions, Pictet,along with several distinguished ICRC delegates, produced the Commentaries in four volumes. See id.Although published under the auspices of the ICRC, the foreword to the Commentaries disclaims themas the personal work of Pictet and his co-authors. Id. at 1. The disclaimer notes that only participantstates are qualified to render official and authentic interpretations of the Conventions. Id. Nonetheless,the Commentaries have commanded a seemingly authoritative force on interpretation of the Conventions.See Hamdan, 548 U.S. at 630–31 (referring to Pictet’s work as the “official commentaries” on the GenevaConventions). As Pictet’s work cautions, citation to the Records of the Geneva Convention DiplomaticConference or state commentary on the Conventions would be more appropriately deemed “official.” Id.

252. In 2002, the U.S. Department of Justice Office of Legal Counsel (“OLC’) offered to the Counselto the President an interpretation of Common Article 3 that restricted its application to the territory ofeach state party. Bybee Memorandum, supra note 8. The OLC surmised that Article 3 did not apply to Rnon-international conflicts that transcended a state’s borders but did not involve more than one stateparty to the Conventions. Id. Scholars increasingly refer to such conflicts as transnational armed conflicts.The U.S. Supreme Court rejected the OLC interpretation in 2006. See Hamdan, 548 U.S. at 630–31.

253. See supra discussion accompanying notes 154–72. R254. Common Article 3 states, “The application of the preceding provisions shall not affect the legal

status of the Parties to the conflict.” 1949 Geneva Convention I, supra note 155, art. 3; see also 1949 RGeneva Convention II, supra note 155, art. 3; 1949 Geneva Convention III, supra note 155, art. 3; 1949 RGeneva Convention IV, supra note 155, art. 3. R

255. COMMENTARY, GENEVA CONVENTION IV, supra note 244, at 37. R256. See supra discussion accompanying notes 249–55 (analyzing Common Article 3 strictly as a posi- R

tive legal provision). Most (if not all) of the substantive provisions of Common Article 3 reflect custom-ary international law. See H.P. Gesser, A Measure of Humanity in Internal Disturbances and Tension: Proposalfor a Code of Conduct, 262 INT’L REV. OF THE RED CROSS 44 (1988). Enforcement of such provisions as



of principles and norms expressed in both international human rights lawand domestic law, it lacks the individual complaint and enforcement provi-sions emblematic of the domestic legal regimes. Common Article 3 thusremains subject to inter-state means of enforcement: politics, diplomacy,international courts, and the use of force. A state engaged in a non-interna-tional armed conflict could, in theory, refuse to entertain complaints fromstates not reciprocally committed to the Conventions as states parties. Undersuch an understanding, only states that had ratified the 1949 Conventionswould have standing to enforce Common Article 3 through the internationallegal system.257

Common Article 3 maintains an element of observational reciprocity aswell. The question of what constitutes an “armed conflict” for purposes ofArticle 3 arose repeatedly at the Diplomatic Conference.258 States were ada-mant that Article 3 could not cover every conceivable act of violence com-mitted within their territories, but rather would be restricted to cases ofinsurgency.259 Although they did not incorporate such provisions into thetext of the Article,260 states enumerated criteria to identify conditions underwhich the Article would apply and to distinguish rebels and insurrectionistsfrom mere bandits and rioters.261 Among the distinguishing characteristicsof an insurgency triggering application of Common Article 3 is that themovement is “prepared to observe the ordinary laws of war” or “agrees to bebound by the provisions of the Convention.”262 Although the condition ofde facto reciprocity that had appeared in earlier iterations was dropped fromthe final version of Common Article 3,263 states created implicit criteria forqualifying insurgencies to retain reciprocity in practice. Thus even whilestates consented to a revolutionary expansion of the reach of internationallaw into their internal affairs, they included a veiled requirement of observa-tional reciprocity.

customary law would operate quite differently and only under conditions of reciprocity identified earlierin the section on reciprocity and customary international law. See supra discussion accompanying notes71–102. R

257. The example is purely theoretical as currently every state has ratified the 1949 Geneva Conven-tions. See States Party to the Main Treaties, International Committee of the Red Cross, http://www.icrc.org/eng (search for “IHL and other treaties” then follow the first link to the PDF) (last visited Mar. 7,2009).

258. COMMENTARY, GENEVA CONVENTION IV, supra note 244, at 35. R259. Id. at 31.260. A draft of what would become Common Article 3 enumerated criteria of insurgencies that would

obligate a state party to apply Common Article 3. See 2B 1949 DIPLOMATIC RECORD, supra note 246, at R46–47. Among the criteria was one requiring that the organization “declares itself bound by the presentConvention, and . . . by the laws and customs of war (and that it complies with the above conditions inactual fact).” Id. at 47 (parenthetical in original).

261. At signature, citing concern for the ambiguity of the phrase “conflict not of an internationalcharacter” and the parties to which the provision would apply, Portugal submitted a reservation toCommon Article 3. See 1949 DIPLOMATIC RECORD, supra note 245, at 351. R

262. COMMENTARY, GENEVA CONVENTION IV, supra note 244, at 36. R263. See 1949 Diplomatic Record, supra note 261 (noting explicit reciprocity clause in working draft). R



Article 1 directly addressed states parties’ exercise of negative reciprocity.It states simply, “The High Contracting Parties undertake to respect and toensure respect for the present Convention in all circumstances.” 264 JeanPictet’s Commentaries to the Conventions point to Common Article 1 asevidence that the Conventions are not engagements “concluded on the basisof reciprocity.”265 Pictet’s Commentaries conceive the Conventions as abinding testimonial, “a series of unilateral engagements solemnly contractedbefore the world . . . .”266 Compared to other provisions common to the fourConventions, Article 1 received scant attention from the drafting commit-tees.267 A member of the joint discussion committee suggested a narrowermeaning than that given by Pictet’s Commentary.268 The Norwegian dele-gation believed “that the object of this Article was to ensure respect of theConventions by the population as a whole.”269 That is, states should ensurenot only that their armed forces were trained under the Conventions, butthat their populations were as well. Claude Pilloud, a delegate of the ICRCwho later assisted in the preparation of Pictet’s Commentaries, respondedthat Article 1 was included in the Stockholm Draft to remind states notonly to apply the Conventions themselves but also to see that the “humanita-rian principles of the Conventions were universally applied.”270

Neither comment suggests that the Conventions apply either universallyor unconditionally. When notions of reciprocity were so thoroughly debatedin the context of other Articles,271 states would not have simply wavedthrough Article 1 with the understanding that it would spell the end ofreciprocity. Along with the thin record of state commentary on Article 1generally, these comments suggest a more modest meaning for Article 1than that offered by Pictet.

264. 1949 Geneva Convention I, supra note 155, art. 1 (emphasis added); see also 1949 Geneva Con- Rvention II, supra note 155, art. 1; 1949 Geneva Convention III, supra note 155, art. 1; 1949 Geneva RConvention IV, supra note 155, art. 1. Article 1 carried over in the preparation of the Stockholm Draft Rfrom the 1929 Prisoner of War Convention’s Article 83 and the 1929 Wounded and Sick Convention’sArticle 25. Only the phrase “in the name of their peoples” was removed. See 2B 1949 DIPLOMATIC

RECORD, supra note 246, at 26. R265. COMMENTARY GENEVA CONVENTION IV, supra note 244, at 15. Kalshoven and Zegveld also R

assert that Article 1 precludes the operation of negative reciprocity under the 1949 Geneva Conventions.KALSHOVEN & ZEGVELD, supra note 55, at 75. They state, “For the 1949 Geneva Conventions the opera- Rtion of this crude principle is excluded by the provision in common Article 1 [sic] that the contractingstates are bound to respect the Conventions ‘in all circumstances.’ ” Id. Kalshoven and Zegveld concedethat negative reciprocity may persist as a legitimate state sanction in the Hague Tradition, includingbans on the use of certain weapons. Id. However, they limit this observation on reciprocity and meansand methods rules to pre-1977 Protocol provisions. Id.

266. COMMENTARY, GENEVA CONVENTION IV, supra note 244, at 25. R267. See 2B 1949 DIPLOMATIC RECORD, supra note 246, at 27. R268. Id. at 53.269. Id.270. Id. (emphasis added).271. See supra notes 253–61 (noting discussion of reciprocity as a condition to applying what would R

become Common Article 3 to non-international armed conflicts).



A full appreciation of Article 1 and reciprocity under the 1949 Conven-tions requires examination of the Conventions’ inner workings. Scholars andwriters have begun to appreciate that the Conventions’ conditions on appli-cability with respect to situations and persons operate in much the same wayas the traditional principle of reciprocity.272 Common Article 2 is the provi-sion most responsible for guaranteeing obligational reciprocity within theConventions. Article 2 interacts with the principle of obligational reciproc-ity in two ways. The opening clause of Article 2 limits states’ obligations toco-parties to the Conventions, stating in relevant part, “[T]he present Con-vention shall apply to cases of declared war or any other armed conflictwhich may arise between two or more of the High Contracting Parties. . . .”273 It is hard to imagine a clearer statement of intent to limit theoperation of the Conventions to conflicts between sovereign, peer competi-tors. For a significant portion of the Conventions’ history, war between astate party and non-party state remained possible and in at least one caseoccurred.274 In such a situation, the Conventions would not have operated ina formal, de jure sense. Article 2 insulated states parties from de jure opera-tion of the Conventions in armed conflicts with non-state actors. The finalclause of Common Article 2 also addresses obligational reciprocity, stating:

Although one of the Powers in conflict may not be a party to thepresent Convention, the Powers who are parties thereto shall re-main bound by it in their mutual relations. They shall further-more be bound by the Convention in relation to the said Power, ifthe latter accepts and applies the provision thereof.275

Although it does not operate with the severity of the 1907 Hague Conven-tions’ si omnes clause or the reservations submitted to the 1925 Gas Protocol,

272. See PROVOST, supra note 197, at 153–56; see also INGRID DETTER, THE LAW OF WAR 411 (2d ed. R2000) (noting a degree of reciprocity in the 1977 Protocols to the Geneva Conventions); Derek Jinks, TheApplicability of the Geneva Conventions to the “Global War on Terrorism,” 46 VA. J. INT’L L. 165, 192–93(2004); Robert Sloane, Prologue to a Voluntarist War Convention, 106 MICH. L. REV. 480 (2008).

273. 1949 Geneva Convention I, supra note 155, art. 2; 1949 Geneva Convention II, supra note 155, Rart. 2; 1949 Geneva Convention III, supra note 155, art. 2; 1949 Geneva Convention IV, supra note 155, Rart. 2.

274. By 1955, only forty-five states had ratified or acceded to the Geneva Conventions, but by 1960seventy-four states had done so. By 1968, forty-four additional states joined the Conventions (bringingthe total number to 118). Another spike in ratifications or accessions occurred in the early 1990s, withtwenty-six countries ratifying the Conventions from 1990 to 1996 (bringing the total number to 187).See States Party to the Main Treaties, International Committee of the Red Cross, http://www.icrc.org/eng(search for “IHL and other treaties” then follow the first link to the PDF) (last visited Mar. 7, 2009).

The civil war in Angola began in the 1960s and “escalated into an increasingly internationalizedconflict” by 1975. Angola did not become party to the Conventions until 1984. However, differentfactions within Angola received military and diplomatic aid from many countries that were alreadyparties to the Conventions, including Cuba, South Africa, and China. STOCKHOLM INT’L PEACE RE-

SEARCH INST. (“SIPRI”), SIPRI YEARBOOK: WORLD ARMAMENTS AND DISARMAMENT 53 (1976).275. 1949 Geneva Convention I, supra note 155, art. 2; 1949 Geneva Convention II, supra note 155, R

art. 2; 1949 Geneva Convention III, supra note 155, art. 2; 1949 Geneva Convention IV, supra note 155, Rart. 2 (emphasis added).



the final clause of Common Article 2 confirms that obligational reciprocityis a precondition to application of the vast majority of the 1949 GenevaConventions. Only non-parties that commit to the Conventions in a de juresense and abide by them in a de facto sense may resort to them for protec-tion vis-a-vis a state party. The condition of de facto application also reflectsa condition of observational reciprocity in Common Article 2. The SpecialCommittee that adopted the text made clear that provisional application ofthe Conventions to non-parties would cease “when it is admitted that a non-signatory State is not applying the Convention.”276

Once a conflict activates the full body of the Conventions through Com-mon Article 2, reciprocity operates in the criteria required for victims of warto benefit from their protections. As their titles suggest, each of the fourConventions identifies a class of so-called “protected persons” that is theprimary focus of its safeguards. The criteria for groups277 to benefit from theprotections of the first three Conventions are nearly identical.278

Article 4 of the Third Convention includes at least two conditions thatguarantee reciprocal acceptance and application of the law of war. The firstcondition requires militias, volunteer corps and resistance movements to sat-isfy four criteria to qualify for prisoner of war (“POW”) status. Only groupsthat conduct “their operations in accordance with the laws and customs ofwar” are accorded POW status.279 Commitment to and compliance with thelaw of war first appeared as a condition for irregular fighters to claim POWstatus in the Brussels Declaration of 1874.280 The Conventions’ law of warcondition simultaneously satisfies states’ desire for observational reciprocityand provides a positive incentive for states to comply with the law of wargenerally.

In addition to state observation of the law of war, the Geneva Conven-tions address individual compliance. Article 85 of the Third Conventioncovers POWs who had not individually complied with the law of war. Thearticle states that “[p]risoners of war prosecuted under the laws of the De-taining Power for acts committed prior to capture shall retain, even if con-victed, the benefits of the present Convention.”281 Thus, POWs who violatethe law of war prior to their capture do not lose their POW status. Instead,

276. 2B 1949 DIPLOMATIC RECORD, supra note 246, at 128. R277. I have commented elsewhere, with co-authors, on the group-level focus of the first three Conven-

tions’ criteria for protected person status. See Geoff Corn, Eric Talbot Jensen & Sean Watts, Understandingthe Distinct Function of the Combatant Status Review Tribunals: A Response to Blocher, 116 YALE L.J. POCKET

PART 327 (2007), available at http://yalelawjournal.org/2007/04/11/corn_jensen_watts.html.278. See 1949 Geneva Convention I, supra note 155, art. 13; 1949 Geneva Convention II, supra note R

155, art. 13; 1949 Geneva Convention III, supra note 155, art. 4. R279. 1949 Geneva Convention III, supra note 155, art. 4. R280. Project of an International Declaration concerning the Laws and Customs of War, Brussels, supra

note 169, art. 9. The criterion was also present in POW qualification criteria of the Hague Regulations Rand the 1929 Geneva Conventions. See 1899 Hague Convention II, supra note 176, Annexed Regulations, Rart. 1; 1907 Hague Convention IV, supra note 179, Annexed Regulations, art. 1. R

281. 1949 Geneva Convention III, supra note 155, art. 85. R



the Detaining Power may prosecute POWs under the same domestic legalregime as its own armed forces.282 Article 85 denies the operation of nega-tive reciprocity at the individual level.

Denying states the opportunity to regard POW protections as inapplica-ble to war criminals drew strong objections from the Soviet Bloc delega-tions. General Slavin of the Soviet delegation remarked: “[T]hose whoviolated the common laws of humanity automatically forfeited their rightsunder the Convention,” and that “none of the provisions of the Conventionshould be applied to war criminals.”283 After failing to amend or remove theprovision from the Convention, these states filed reservations insisting on aloose version of negative reciprocity at the individual POW level.284 TheWarsaw Pact objections and reservations reflect clear insistence on observa-tional reciprocity not only as a matter of general state practice but on anindividual level as well. Under the Soviet reservations only militants’ per-sonal observation of the Conventions guarantees their reciprocal application.

The second condition of reciprocity required for groups to receive POWstatus is less obvious. Where the requirement to accept and apply the law ofwar is clearly enumerated in itemized format, the requirement that suchgroups claiming POW status belong to a state party is easy to miss. UnderArticle 4, only militias, volunteer corps, and resistance movements “belong-ing to a Party to the conflict” qualify for POW status. In other words, stateimprimatur is a precondition to any group qualifying for POW status.Armed groups taking part in international armed conflicts must trace theirauthority to do so back to a state party to the Conventions. This require-ment ensures that an actor with international legal personality assumes re-sponsibility for the group’s conduct. Furthermore, the requirement limitsobligational reciprocity because only states can ratify the Conventions. Evennon-state actors that fastidiously satisfy each of the four itemized criteria inArticle 4 do not merit Geneva POW status without state imprimatur.

Like the first three Conventions, the Fourth Geneva Convention, whichprotects civilians, includes a provision outlining preconditions to the major-ity of its protections. Article 4 of the Fourth Convention is the gateway tothe most extensive and elaborate protections for civilians.285 Essentially, any

282. See id. art. 102.283. 2A FINAL RECORD OF THE DIPLOMATIC CONFERENCE OF GENEVA OF 1949, at 321 (William S.

Hein & Co. 2004) (1950).284. Their reservations operated to deny the law of war to persons who had not observed it. Thus,

Hungary submitted a reservation to Article 85 stating, “prisoners of war convicted of war crimes . . .must be subject to the same treatment as criminals convicted of other crimes.” 1949 DIPLOMATIC RE-

CORD, supra note 245, at 347. Albania, Bulgaria, Poland, Romania, Czechoslovakia, and the Soviet RUnion. Id. at 342–55.

285. 1949 Geneva Convention IV, supra note 155, art. 4. Article 4 reads in relevant part: R

Persons protected by the Convention are those who, at any given moment and in any mannerwhatsoever, find themselves, in case of a conflict or occupation, in the hands of a Party to theconflict or Occupying Power of which they are not nationals.Nationals of a State which is not bound by the Convention are not protected by it.



person finding herself in the hands of her nation’s enemy qualifies as a “pro-tected person” under the Fourth Convention.286 During international armedconflict, nationals of states parties that are either in enemy territory or findtheir own territory occupied by an enemy state party must be accorded pro-tected status. The Convention leaves nationals of non-party states largelyunprotected.287 Thus Article 4 sustains the condition of obligational reci-procity by denying protected person status to nationals of states not party tothe Conventions. It provides further evidence that, while states were eager torectify the humanitarian shortcomings of the preexisting law of war, theywould only do so on the basis of reciprocal commitment.288

Like most international agreements and treaties, the Geneva Conventionsinclude withdrawal provisions. Article 158 of the Fourth Convention is rep-resentative of the Conventions’ approach to withdrawal.289 Article 158 per-mits states to withdraw from the legal effect of ratification upon one year’snotice.290 However, denunciation does not take effect in ongoing conflictsinvolving the denouncing state party. Furthermore, Article 158 makes clearthat withdrawal from the Conventions does not create a legal void. Statesexercising withdrawal under Article 158 remain subject to “the principles ofthe law of nations” and specifically to norms traditionally preserved by theMartens Clause.291 Not surprisingly, the Article limits the effect of denunci-ation to the denouncing party, preserving operation of the Conventions be-tween remaining states parties.

Commentators have cited Article 158 as evidence of a renunciation ofnegative reciprocity.292 While in a sense accurate, such claims overstate theeffect of Article 158 and fail to appreciate how the Conventions’ conditionson application, outlined previously, operate as conditions of reciprocity.First, where Article 158 would deny legal effect to a state’s denunciation ofthe Conventions that was precipitated by failure of observational reciprocityduring an ongoing armed conflict with the breaching state, the effect would

Id.; see COMMENTARY, IV GENEVA CONVENTION, supra note 244, at 4–5 (noting the unprecedented scope Rand scale of protections provided by the Fourth Convention); see also Knut Dormann, The Legal Situationof Unlawful/Unprivileged Combatant, 85 INT’L REV. RED CROSS 45, 60–61 (2003) (summarizing and classi-fying the Fourth convention’s extensive and detailed protective regime for civilians).

286. Civilians who do not meet the nationality criteria of the Article 4 are limited to protections ofPart II of the Fourth Convention. See 1949 Geneva Convention IV, supra note 155, art. 4. R

287. Nationals of states not parties to the Conventions qualify only for protection under CommonArticle 3 and Part II of the Fourth Geneva Convention. 1949 Geneva Convention IV, supra note 155, Rarts. 4, 13.

288. The universal ratification of the Conventions overcame this category. See supra note 274. R289. Article 158 is common to the four of the 1949 Geneva Conventions. It appears as articles 63, 62,

and 142, respectively, in the first three Conventions. See Geneva Convention I, supra note 155, art. 63; RGeneva Convention II, supra note 155, art. 62; Geneva Convention III, supra note 155, art. 142. R

290. Geneva Convention IV, supra note 155, art. 158. R291. Article 158 reads in relevant part: “[Denunciations] shall in no way impair the obligations

which the Parties to the conflict shall remain bound to fulfil by virtue of the principles of the law ofnations, as they result from the usages established among civilized peoples, from the laws of humanityand the dictates of the public conscience.” Geneva Convention IV, supra note 155, art. 158. R

292. BOUCHET-SAULNIER, supra note 7, at 137. R



be merely to delay termination of the Conventions rather than to deny with-drawal entirely. Following denunciation, the Conventions would not operatein a subsequent armed conflict between the breaching and victim states.Further, the option of declining to apply the Conventions to groups of per-sons not meeting the Conventions’ protected person criteria would remainavailable to the victim state and vindicate most of the concerns that havetraditionally informed the principle of reciprocity. It remains unclearwhether Article 158 would entirely foreclose suspension of an individualprovision of the Conventions under the traditional law of treaties.

The arc of late-nineteenth and early to mid-twentieth century efforts tocodify the law of war reflected a growing trend away from blunt expressionsof reciprocity. States gradually abandoned formal conditions on obligationalreciprocity, including the si omnes clause and reservations to its effect, andlimited their resort to negative reciprocity as a means of self-help in responseto failures of observational reciprocity. Yet states simultaneously preservedthe function of former conditions on reciprocity through restrictive secon-dary rules. This preservation limits the application of the law of war toconflicts with peer competitors and groups similarly committed to honoringthe customs and usages of the traditional law of war. Subsequent develop-ments in both the law of war and the law of treaties would introduce newconsiderations into the debate concerning the continued vitality and propri-ety of the principle of reciprocity.

IV. MODERN DEVELOPMENTS OF THE PRINCIPLE OF RECIPROCITY

The traditional principle of reciprocity both reflects and reinforces an in-ternational legal system dominated by sovereigns. Negative reciprocity, ameasure of state self-help, follows easily from a system that sees the state asthe true and perhaps exclusive beneficiary of international legal norms. Asillustrated above, the law of war has historically adhered to such traditionalnotions of reciprocity. Even while states shed coarse conditions of reciprocalobligation and observance like the si omnes clause, they preserved the contin-gency of their international legal obligations by reserving application of thevast majority of the law to peer competitors. Thus, like the traditional prin-ciple of reciprocity, the established law of war has reinforced the sovereignfocus of the international legal system.

In the late twentieth century, academic and judicial circles questioned thevitality of that system, warranting an examination of how such develop-ments impact reciprocity.293 The evolution in the law of treaties mentioned

293. See generally MERON, THE HUMANIZATION OF INTERNATIONAL LAW, supra note 71 (compiling a Rseries of the authors’ earlier articles emphasizing individuals’ growing roles in international law); GeorgeAbi-Saab, The Specificities of Humanitarian Law, in STUDIES AND ESSAYS ON INTERNATIONAL HUMANITA-

RIAN LAW AND RED CROSS PRINCIPLES IN HONOUR OF JEAN PICTET (Christophe Swinarski ed., 1984).



previously294 includes a reconceptualization of the contractual nature of trea-ties. While conceding the synallagmatic nature of most treaties, interna-tional scholars have characterized some treaties as non-contractual.Sometimes called “law-making treaties,” these instruments are argued toevince obligations of a general or even ubiquitous nature.295 These are usu-ally multilateral treaties, stating broad, normative rules of conduct applica-ble across the spectrum of states parties’ international conduct. Somecommentators cite such treaties as evidence of a relative decline in the im-portance of sovereignty to evaluating and applying international legalrules.296 More importantly, “law-making treaties” are frequently said to re-gard individuals rather than states as their primary beneficiaries.

As modern conflicts have proved that existing law of war instrumentsinadequately protect the full range of humanitarian interests in the welfareof civilians and victims of war, a less sovereign-focused outlook on protec-tions has emerged. It is not uncommon to hear states’ obligations under thelaw of war referred to as “rights” that vest in individuals.297 Such reconcep-tions coincide with a broader recognition of transnational relationships andindividuals as proper subjects of international law.298 This evolution is notonly apparent from human rights instruments and scholarship but has foundits way into the secondary rules governing international law, including thetreatment of reciprocity by the law of treaties. A number of sources haveleveraged the emerging non-sovereigntist conception of international law toreduce reciprocity’s role in the law of war. Recognizing the interaction be-tween such emerging secondary rules and the law of war is critical to acomplete understanding of the modern doctrine of reciprocity.

A. The 1969 Vienna Convention on the Law of Treaties

The Vienna Convention on the Law of Treaties299 is integral to the argu-ment that reciprocity no longer conditions law of war obligations. The Con-

294. See supra discussion accompanying note 27. R295. SHAW, supra note 32, at 89–90 (citing the Genocide Convention and the Vienna Convention on R

Diplomatic Relations of 1961 as examples of “law-making” treaties); see also C. Wilfred Jenks, TheConflict of Law-Making Treaties, 30 BRIT. Y.B. INT’L L. 401 (1953); Molly C. Quinn, Life Without Parolefor Juvenile Offenders: A Violation of Customary International Law, 52 ST. LOUIS U. L.J. 283, 291 (2007)(quoting Ian Brownlie, PRINCIPLES OF PUBLIC INTERNATIONAL LAW 6 (6th ed. 2003)).

296. Harold Koh, Why Do Nations Obey International Law?, 106 YALE L.J. 2599 (1997).297. Aya Gruber, Who’s Afraid of Geneva Law?, 39 ARIZ. ST. L.J. 1017 (2007) (discussing the trend in

U.S. Supreme Court decisions to accept the Geneva Conventions and international law as domesticallybinding); Jason W. Hobbes, To Boldly Go Where No Signatory Has Gone Before: How the Military Commis-sions Act of 2006 Has Rewritten the United States’ Obligations Under the Geneva Conventions, 26 PENN. ST.INT’L L. REV. 489 (2007) (commenting that the Military Commissions Act of 2006 shifted the UnitedStates’ interpretation of its responsibilities under the Geneva Conventions). The Conventions themselvesoften use the term “rights” within the text of the Articles. 1949 Geneva Convention I, supra note 155, Rart. 6; 1949 Geneva Convention III, supra note 155, art. 105; 1949 Geneva Convention IV, supra note R155, art. 27. R

298. Koh, supra note 296, at 2599. R299. Vienna Convention, supra note 27. R



vention purports to regulate the most important aspects of the internationaltreaty system.300 A number of sources, including U.S. government adminis-trations301 and U.S. federal courts,302 regard the Vienna Convention as gen-erally reflective of customary international law.303 However, it may be moreaccurate to regard the Convention as it was viewed when drafted, as a mix-ture of codified pre-existing practice and “progressive development” on sub-jects not fully realized in international law.304

The Convention codified a significant portion of the pre-existing custom-ary law of treaties.305 Article 60 of the Convention addresses states’ exerciseof negative reciprocity in response to breaches of treaty obligations.306 TheArticle’s provisions on suspension of treaty obligations reflected acceptedcustomary limits and conditions on state practice with respect to negativereciprocity.307 Article 60 sustains states’ freedom to suspend performance ofa broad range of positive legal obligations when confronted with breach.

Despite this codifying effect, Article 60 also challenged traditional stateprerogatives. In particular, paragraph 5 supports the emerging non-sover-eigntist view of international legal obligations, stating, “Paragraphs 1 to 3do not apply to provisions relating to the protection of the human personcontained in treaties of a humanitarian character, in particular to provisionsprohibiting any form of reprisals against persons protected by such trea-ties.”308 As borne out by its drafting history, paragraph 5 reads almost as anafterthought to Article 60. Whereas the first three paragraphs of Article 60were the product of extensive debate and decades of scholarly and committee

300. See IAN SINCLAIR, THE VIENNA CONVENTION ON THE LAW OF TREATIES 5 (1973).301. See John Norton Moore, Enhancing Compliance with International Law: A Neglected Remedy, 39 VA.

J. INT’L L. 881, 891–92 (1999) (citing Letter of Submittal from Secretary of State William P. Rogers tothe President, Transmitting the Vienna Convention (Oct. 18, 1971) at 1 and Written Statement byDeputy Legal Adviser Mary V. Mochary Before the Senate Foreign Relations Comm. (June 11, 1986) at1). Each letter characterizes the majority of the Vienna Convention as reflective of the customary interna-tional law of treaties. Id.

302. Fujitsu Ltd. v. Fed. Exp. Corp., 247 F.3d 423, 433 (2d Cir. 2001). Applying the Convention,the court observed, “we rely upon the Vienna Convention here ‘as an authoritative guide to the custom-ary international law of treaties.’ ” Id. (quoting Chubb & Son, Inc. v. Asiana Airlines, 214 F.3d 301, 309(2d Cir. 2000)).

303. See I.C.J. Namibia Advisory Opinion, supra note 56, ¶ 94. The Court observed, “The rules laid Rdown by the Vienna Convention on the Law of Treaties concerning termination of a treaty relationshipon account of breach (adopted without a dissenting vote) may in many respects be considered as a codifi-cation of existing customary law on the subject.” Id.; see also Frankowska, supra note 63, at 298 (address- Ring U.S. courts’ treatment of the Convention as reflective of customary law).

304. SINCLAIR, supra note 300, at 11–12. The Convention’s preamble acknowledges a developmental Raspect noting a “progressive development of the law of treaties achieved in the present Convention . . . .”Vienna Convention, supra note 27, pmbl. R

305. See I.C.J. Namibia Advisory Opinion, supra note 56, ¶ 94. R306. See supra discussion accompanying notes 56–61. R307. Frankowska notes that although the United States has not ratified the Convention, it has re-

sorted to Article 60 in its treaty relations with other states. Frankowska, supra note 63, at 300. In Rresponse to Vietnamese suspension of the 1973 Paris Peace Treaty on claims of the breach by the UnitedStates, the United States cited Article 60, specifically the topics covered in paragraphs 1 through 3, asreflective of custom. Id. at 300, n.85.

308. Vienna Convention, supra note 27, art. 60, ¶ 5. R



work,309 paragraph 5 appeared in a plenary committee session as an oralamendment offered by the Swiss delegation.310 Mohammed Gomaa charac-terized paragraph 5 as “an innovation of the Conference.”311 When intro-ducing the written amendment, a Swiss delegate described the 1949 GenevaConventions, as well as conventions on refugees, genocide, and “humanrights in general,” as instruments that should not be subject to traditionalnotions of reciprocal suspension or termination.312 Records of discussion ofthe Swiss amendment are sparse.313 While several states commented on thedesirability of the rule, none referred to any pre-existing custom to the sameeffect. Nor did the proposal replicate any provision in existing law of wartreaties. Ultimately, the plenary Committee adopted the Swiss amendmentby a vote of 87 votes to none, with nine abstentions.314

Despite its humble origins, the doctrinal consequences of paragraph 5 forconflict regulation are potentially enormous. Paragraph 5 might represent amajor shift in both the theoretical and doctrinal underpinnings of the prin-ciple of reciprocity. On the theoretical level, paragraph 5 signifies a majorcoup for jurists and interests dissatisfied with the persistence of reciprocityin the law of war. It clearly characterizes humanitarian obligations as dutiesowed erga omnes rather than inter partes.315 From this transformation, accord-ing international legal personality to individuals under humanitarian trea-ties is an attractive and understandable next step. Paragraph 5 thus signifiesa major shift away from the sovereigntist view of the law of war and otherhumanitarian legal disciplines.

309. See ROSENNE, supra note 32, at 33–34. Shabtai Rosenne attended the Vienna Convention Diplo- Rmatic Conference as a delegate for the State of Israel. Rosenne contributed to committee’s discussions onthe Article 60 of the Vienna Convention. See U.N. Conference on the Law of Treaties, 2d Sess., 21st plen.mtg. ¶¶ 34–37, U.N. Doc A/CONF.39/11.Add.1 (May 13, 1969).

310. Mohammed M. Gomaa reports that Sir Gerald Fitzmaurice, a Special Rapporteur of the ILC,proposed to exempt human rights treaties, labor conventions, and maritime safety conventions fromtermination or suspension upon breach. MOHAMMED M. GOMAA, SUSPENSION OR TERMINATION OF TREA-

TIES ON GROUNDS OF BREACH 106–07 (1996). Later, Special Rapporteurs declined to include the exemp-tion in drafts of the ILC’s work. Id. Review of the diplomatic record of the Convention indicates thatSwitzerland first proposed the concept captured in paragraph 5 in a plenary meeting at the 1968 Sessionof the Conference. See U.N. Conference on the Law of Treaties, 1st Sess., 61st plen. mtg. ¶ 12, U.N. DocA/CONF.39/11 (May 9, 1968). The Swiss renewed their proposal the next year at another plenary ses-sion. U.N. Conference on the Law of Treaties, 2d Sess., 21st plen. mtg. ¶ 22, U.N. Doc A/CONF.39/11.Add.1 (May 13, 1969).

311. GOMAA, supra note 310, at 107. R312. U.N. Conference on the Law of Treaties, 2d Sess., 21st plen. mtg. ¶ 21, U.N. Doc A/CONF.39/

11.Add.1 (May 13, 1969).313. Sir Humphrey Waldock, an unaligned expert consultant to the Conference, noted concern that

paragraph 5 would conflict with many existing termination provisions contained in existing treaties.Waldock observed that the persistence of rules that had matured into custom and jus cogens would servethe same interests addressed by the Swiss delegation’s amendment. U.N. Conference on the Law ofTreaties, 1st Sess., 61st plen. mtg. ¶ 76, U.N. Doc A/CONF.39/11 (May 9, 1968).

314. ROSENNE, supra note 32, at 319. R315. For an exhaustive analysis of erga omnes in the international obligations, see generally MAURIZIO

RAGAZZI, THE CONCEPT OF INTERNATIONAL OBLIGATIONS ERGA OMNES (1997).



The potential doctrinal byproducts of paragraph 5 are no less significant.In its broadest interpretation, paragraph 5 would insulate the law of warentirely from the reciprocity-based remedies of the first three paragraphs ofArticle 60.316 A maximalist reading of paragraph 5 accords with a move-ment toward conflating human rights and international humanitarian lawinto a general and truly universal international law of humanitarian con-cerns.317 The extent to which human rights law and the law of war merge,coexist, overlap, or even conflict is the subject of extensive academic debateand literature.318 A complete survey of the field, much less an effective de-fense of a viewpoint in this debate, is well beyond the scope of this Arti-cle.319 For purposes of this Article, however, it is sufficient to note thatparagraph 5 of the Vienna Convention arguably supports a viewpoint thatregards human rights law and the law of war as at least equivalent in termsof their purported rejection of negative reciprocity as a means of state self-help.320 Paragraph 5 might be read to acknowledge no distinction betweenhuman rights law and the law of war in terms of suspension or terminationof legal norms as responses to failures of obligational or observationalreciprocity.

316. GOMAA, supra note 310, at 109. R317. Paragraph 5 might express a human rights-like theory of the obligation to protect victims of

war—a monumental development when one considers the history of the law of war illustrated earlier. Asdemonstrated above, early thought on war conflated the person and state. Combatants and even civilianswere conceived as extensions of the state. One of the theoretical developments in armed conflict criticalto the modern law of war was Rousseau’s contention that war should not be conceived as a conflictbetween persons. “War then, is not a relation between man and man, but a relation between State andState, in which individuals are enemies only by accident, not as men, nor even as citizens, but as soldiers;not as members of their fatherland, but as its defenders. In short, each State can have as enemies onlyother States and not individual men; inasmuch as it is impossible to fix any true relation between thingsof different natures.” JEAN JACQUES ROUSSEAU, 1 SOCIAL CONTRACT OR PRINCIPLES OF POLITICAL RIGHT,ch. 4 (Charles M. Stover trans., The New American Library 2d ed. 1974) (1762). The rights-basedconception of the law of war carries this evolution further, characterizing rights that persist in the con-text of armed conflict and restrain states’ efforts.

318. See YORAM DINSTEIN, THE CONDUCT OF HOSTILITIES UNDER THE LAW OF INTERNATIONAL

ARMED CONFLICT 20–25 (2004); see also Michael J. Dennis, Application of Human Rights Treaties Extraterri-torially to Detention of Combatants and Security Internees: Fuzzy Thinking All Around?, 12 ILSA J. INT’L &COMP. L. 459 (2006); Aaron Xavier Fellmeth, Questioning Civilian Immunity, 43 TEX. INT’L L.J. 453(2008) (detailing the interplay between the law of war and human rights law in terms of civilian casual-ties); Monica Hakimi, International Standards for Detaining Terrorism Suspects: Moving Beyond the ArmedConflict-Criminal Divide, 33 YALE J. INT’L L. 369 (2008) (discussing the difference between detaining anindividual within the laws of war or within the peacetime laws of human rights); Francisco ForrestMartin, Establishing a Unified Use of Force Rule, 64 SASK. L. REV. 347 (2001); Dietrich Schindler, HumanRights and Humanitarian Law: Interrelationships of the Laws, 31 AM. U. L. REV. 935, 941–42 (1982);Kenneth Watkin, Controlling the Use of Force: A Role for Human Rights Norms in Contemporary Armed Con-flict, 98 AM. J. INT’L. L. 1, 2–6 (2004).

319. Rene Provost provides the most thorough exploration of the interaction between human rightslaw and the law of war. See generally supra note 197. Provost offers a nuanced exploration of how the two Rlegal systems differ, overlap, and may in some cases be reconciled, including an excellent comparison onhow reciprocity may operate differently within the two disciplines. Id.

320. The Swiss delegation, in its discussion proposing paragraph 5, mentioned the Geneva Conven-tions and major human rights instruments all at once. See supra discussion accompanying note 310, ¶ 21. R



In fact, the nature of the treaty-based norm in question may limit nega-tive reciprocity. If classic international law conceived of treaties as contracts,it regarded states as the parties in privity.321 To continue the contractualanalogy, causes of action for breach accrued to states, not to individual per-sons whom they may incidentally have affected. However, modern humanrights treaties present an exception and illustrate the growing “humaniza-tion” of international law in some circles.322 Rather than recognize states astheir primary beneficiaries, human rights treaties are frequently thought tobenefit individuals. While treaties predating the mid-twentieth century in-ternational human rights movement often benefitted individuals,323 suchbenefits were incidental and usually owing to the person’s status as de factochattel, or at least interests, of the sovereign. Most modern human rightstreaties operate differently. They elevate interactions between the state andindividuals to concerns of international law. Persons may thus be said togain a limited degree of international personality from human rights trea-ties.324 In this sense that human rights treaties are said to be obligationsowed erga omnes as opposed to inter partes.325

Negative reciprocity loses much of its logical and legal relevance underthis conception of human rights treaties. When an obligation is owed pri-marily to individuals, a breach occurring between State A and such individ-uals would not occasion suspension between State B and other, or even thesame, individuals.326 The effects of any reciprocal suspension or terminationof the norm in question by State B would miss their mark almost entirely.For this reason, international human right treaties are said to operate largelyfree from conditions of observational reciprocity and the sanction of negativereciprocity.

Extrapolating human rights treaties’ conception of the legal status of in-dividuals to the law of war is an attractive step. If the law of war protectsindividuals from states rather than states’ interests in individuals and mili-tary goals, the logic of negative reciprocity quickly evaporates. State A’sfailure to observe the law of war with respect to nationals of State B wouldnot warrant suspension of the relevant norms by B. The nationals of State A,having had no part in the earlier breach by their state, would continue toenjoy protection throughout the armed conflict.

321. See supra discussion accompanying notes 32–37. R322. See generally MERON, THE HUMANIZATION OF INTERNATIONAL LAW, supra note 71. R323. See, e.g., Convention for the Amelioration of the Condition of the Wounded in Armies in the

Field, Aug. 22, 1864, 129 Consol. T.S. 361.324. A number of human rights treaties included provisions for individual complaints against states

parties. See, e.g., Optional Protocol to the International Covenant on Civil and Political Rights, opened forsignature Dec. 19, 1966, 999 U.N.T.S. 302 (entered into force Mar. 23, 1976).

325. PROVOST, supra note 197, at 167. R326. Noah Feldman, Ugly Americans, in THE TORTURE DEBATE IN AMERICA 267, 275–76 (Karen

Greenberg ed., 2006).



Yet textual limits within paragraph 5 of the Vienna Convention and tem-poral limits on application of the Convention generally caution against sucha drastic reconceptualization of the law of war. First, paragraph 5’s restric-tion on negative reciprocity addresses only “provisions relating to the pro-tection of the human person.”327 While the law of war has long made suchefforts a priority, humanitarian provisions have not been its exclusive fo-cus.328 The law of war includes important affirmative authority to use armedforce against persons; to destroy, confiscate or requisition property; and todetain persons. Indeed, an ICRC instructor reputedly regarded the right tokill as “the first principle of the law of war.”329 A number of treaties fromthe Hague Tradition, including the 1925 Geneva Protocol and the 1980Convention on Conventional Weapons and its Protocols, defy the categoricallabel “humanitarian treaty.” Such provisions or treaties might be outsidethe scope of the paragraph 5 “provisions relating to the protection of thehuman person” and thus still subject to traditional conditions of reciprocalobligation and observance.

The Vienna Convention’s general rule of non-retroactivity may be a sec-ond limit on the effect of paragraph 5. Article 4 states, “[T]he Conventionapplies only to treaties which are concluded by States after the entry intoforce of the present Convention with regard to such States.”330 At a mini-mum, treaties concluded prior to January 27, 1980 would not be subject asa matter of conventional law to the reciprocity regime outlined in Article60.331 Even today, most law of war treaties predate the Vienna Convention’sentry into force.332 The same temporal restriction holds true for a number ofthe human rights instruments specifically mentioned in the discussions thatled to the adoption of paragraph 5.

Thus Article 60, Paragraph 5 could only operate on earlier treaties such asthe 1899/1907 Hague Regulations, the 1949 Geneva Conventions, and the1977 Additional Protocols to the Geneva Conventions under a theory thatits rejection of negative reciprocity reflected custom. To be more precise, atleast one of two possibilities must be true for paragraph 5 to operate on themajority of major law of war treaties. First, paragraph 5 could have reflectedor codified a pre-existing customary rule at the time it was drafted.333 Alter-

327. Vienna Convention, supra note 27, art. 60, ¶ 5. R328. See DINSTEIN, supra note 318, at 1. R329. FRESARD, supra note 120, at 22. Fresard declines to name the instructor and merely calls him or R

her “a pioneer among ICRC military instructors.” Id.330. Vienna Convention, supra note 27, art. 4. R331. The Vienna Convention entered into force on January 27, 1980, supra note 27, art. 4. R332. For instance, the 1899 Hague Conventions and its annexed Regulations entered into force on

September 4, 1900. SCHINDLER & TOMAN, supra note 137, at 56. The 1907 Hague Regulations entered Rforce on January 26, 1910. Id. The 1949 Geneva Conventions entered force on October 21, 1950. Id. at459. The 1977 Additional Protocols I & II to the Geneva Conventions entered force on December 7,1978. Id. at 711.

333. Article 3 of the Vienna Convention states:



natively, paragraph 5 may have matured since its development in 1969 intoa customary rule with retroactive effect on treaties of a humanitarian nature.

At least one commentator has attributed customary status to paragraph 5at the time of its drafting.334 The ICJ has also stated in dictum that para-graph 5 reflected custom.335 The International Criminal Tribunal for Yugo-slavia applied paragraph 5 to the 1949 Geneva Conventions, stronglysuggesting that the Tribunal attributes customary status to paragraph aswell.336 A recent study of the customary law of war captures the modernposition on the effect of paragraph 5 and the state of reciprocity in the law ofwar generally. Rule 140 of the study states, “[T]he obligation to respect andensure respect for international humanitarian law does not depend on reci-procity.”337 Commentary on rule 140 cites paragraph 5 to support the claimthat respect for treaties of a “humanitarian nature” is independent of otherstates’ respect for those instruments.338

Yet the customary status of paragraph 5 is dubious.339 For instance, thecircumstances leading to the inclusion of paragraph 5 in the Vienna Conven-tion do not suggest an intent to codify existing custom.340 None of the threemajor drafting efforts that led to the Convention explored a humanitarianexception to the reciprocity regime ultimately codified in Article 60.341

The fact that the present Convention does not apply to international agreements concludedbetween States and other subjects of international law or between such other subjects of inter-national law, or to international agreements not in written form, shall not affect:(a) the legal force of such agreements;(b) the application to them of any of the rules set forth in the present Convention to which theywould be subject under international law independently of the Convention;(c) the application of the Convention to the relations of States as between themselves underinternational agreements to which other subjects of international law are also parties.

Vienna Convention, supra note 27, art. 3. Article 3(b) contemplates the operation of preexisting secon- Rdary rules on treaty interpretation and application drawn from custom.

334. Gomaa asserts that paragraph 5 reflected, at the time of its drafting, an existing rule of custom-ary international law. GOMAA, supra note 310, at 113. R

335. I.C.J. Namibia Advisory Opinion, supra note 56, ¶ 94. R336. The Tribunal stated:

Article 60(5) [of the Vienna Convention] provides that such reciprocity or in other words theprinciple inadimplenti non est adimplendum does not apply to provisions relating to the protec-tion of the human person contained in treaties of a humanitarian character, in particular theprovisions prohibiting any form of reprisals against persons protected by such treaties.

Prosecutor v. Kupreskic, Case No. IT-95-16-T, Judgment, ¶ 520 (Jan. 14, 2000).337. 1 CUSTOMARY INTERNATIONAL LAW: RULES 498 (Jean-Marie Henckaerts & Louise Doswald-

Beck eds., 2005).338. Id. at 499.339. Elisabeth Zoller has expressed skepticism at the general applicability and reach of Article 60. She

posits that attributing customary status to Article 60 “has so many distorting effects on internationalrelations that it cannot purport to be an exact image of the international law in force.” ZOLLER, supranote 9, at 17–18. R

340. See supra discussion accompanying note 311. R341. Legal historians have identified three major drafting efforts leading to the Vienna Convention.

See ROSENNE, supra note 32, at 30–41; Richard D. Kearney & Robert E. Dalton, The Treaty on Treaties, 64 RAM. J. INT’L L. 495, 496–502 (1970). The first was the 1925 Project 21 of the American Institute ofInternational Law. Id. The Project produced the so-called Havana Convention on Treaties. Conventions



Neither the exhaustive survey of treaty law conducted by the Harvard Pro-ject nor the decades of preparatory work conducted by the International LawCommission noted an exception to general rules of negative reciprocity forhumanitarian instruments or norms. Rather, the preparatory work for theConvention conveys the impression that the Swiss amendment was an inno-vation intended to remedy a normative oversight in existing law.

The contemporaneous works of prominent commentators also fail to sup-port the existence of a customary humanitarian law exception to the generalreciprocity regime. Less than a decade prior to the Vienna Conference, Stonestated, “The premise on which retaliation in war proceeds is, indeed, that abelligerent’s duty to observe the laws of war is not absolute, but conditionalon the enemy’s reciprocation.”342 Also, Schwarzenberger noted, “The laws ofwar constitute a typical illustration of the international law of reciproc-ity.”343 Just three years after the Vienna Convention was signed, heobserved:

[A] belligerent when confronted with large-scale breaches of thelaws of war on the part of the adversary “may . . . prefer to take. . . immediate action and, by his reprisals, reverse the operationof the chief working principle behind the laws of war from posi-tive, to negative, reciprocity.”344

Other contemporaneous developments in the law of war further clarify theextent to which paragraph 5 either reflected or had matured into custom.

B. The 1977 Additional Protocols to the Geneva Conventions

Commentary on and development of the law of war following the ViennaConvention was not limited to experts. After the Vienna Conference con-

on Public International Law Adopted by the Sixth International American Conference, Convention onTreaties, Feb. 20, 1928, reprinted in 22 AM. J. INT’L L. SUPP. 138–42 (1928). The second major effort tocodify the law of treaties was the Harvard Research in International Law. ROSENNE supra note 32, at 31. RThe Harvard draft convention on the Law of Treaties included thirty-six articles accompanied by over500 pages of commentary. Article 27 of the draft treaty addressed responses to treaty violations, authoriz-ing suspension of performance in response to breach. Harvard Research in International Law, reprinted inTHE HARVARD RESEARCH IN INTERNATIONAL LAW: ORIGINAL MATERIALS 662–63 (John P. Grant & J.Craig Barker eds., 2008). Article 27 proposed a system of arbitration as the primary means to addressbreach of treaty obligations never adopted by states. Id. Neither the draft nor commentaries suggest anexception for humanitarian provisions or treaties. Id. at 1094–95. Finally, the U.N. International LawCommission, as part of its broader effort to codify “the whole field of international law,” began in 1949 astudy on the law of treaties. See ROSENNE, supra note 32, at 32 (quoting Statute of the International Law RCommission, G.A. Res. 174 (II), art. 18, U.N. Doc. A/519 (Nov. 21, 1947)). The ILC’s Draft Article 57addresses termination or suspension as a consequence of breach. Id. Draft Article 57 differs substantiallyonly from its final version at Article 60 of the Vienna Convention in its omission of a provision compara-ble to paragraph 5. Id. The commentary to Draft Article 57 reflects a focus on the nature of the breachrather than the nature of the obligation breached in determining the availability of negative reciprocity.Id. at 73–75. The commentary includes no discussion of special treatment for humanitarian treaties. Id.

342. STONE, supra note 150, at 354. R343. SCHWARZENBERGER, supra note 55, at 452. R344. Id. at 453.



cluded its effort to codify the law of treaties, states set out to update andfurther codify the law of war. Between 1974 and 1977, states met at Genevato conclude what became the 1977 Additional Protocols to the 1949 GenevaConventions.345 Even today, the 1977 Additional Protocols stand out as themost significant revision and update of the law of war since the 1949 Con-ventions. The Protocols not only purported to reform the application of thelaw of war to emerging forms of conflict such as wars of national libera-tion346 but also worked a revolutionary merger of the jus in bello’s previouslybifurcated Hague and Geneva traditions.347

One might have expected the ambitious Protocols to address explicitly oreven reform the relationship between the law of war and the principle ofreciprocity. Like their predecessors, the Protocols entered force prior to theVienna Convention, insulating them from the effect of Article 60, paragraph5 as a matter of conventional law. The drafters could have made a deliberateeffort to clarify the effect of paragraph 5 before that treaty took effect. Ifthey believed that paragraph 5 merely reflected custom, they could haveexcluded reciprocity from the Protocols. Alternatively, they could have in-cluded paragraph 5 by reference. Yet the Protocols neither unequivocallyrejected the doctrine of negative reciprocity nor extinguished the veiled andsubtle vestiges of reciprocity found in earlier twentieth century law of warinstruments.

To be sure, Protocol I includes some indicia of intent to limit the opera-tion of negative reciprocity. Article 1 restates the commitment to “ensurerespect for the Conventions in all circumstances” found in Article 1 of the1949 Conventions. Echoing the Commentary to the 1949 version, the Com-mentary to Protocol I, Article 1 advocates a universalist understanding ofthe Geneva Conventions and an aversion to conditions of formal reciproc-ity.348 In fact, the Commentary specifically cites Article 60, paragraph 5.349

Protocol I, Article 96(3) also provides non-parties the opportunity to effec-

345. See generally Protocol I, supra note 33. R346. Article 1, paragraph 4 is one of the most controversial provisions of Additional Protocol I.

Article 1, paragraph 4 expands coverage to conflicts between states parties and national liberation move-ments or organizations fighting racist regimes. Id. art. 1, ¶ 4.

347. While the 1949 Geneva Conventions supplemented previous iterations of the Geneva Traditionfollowing the Second World War, the treaties of the Hague Tradition, including the Fourth HagueConvention and its Regulations, remained essentially unchanged from 1899 through 1977. Only the1954 Hague Cultural Property Convention managed to codify modern rules for the conduct of hostilitiesand use of weapons. See Convention for the Protection of Cultural Property in the Event of ArmedConflict, May 14, 1954, 249 U.N.T.S. 215. Despite monumental changes state’s conduct of hostilities,the Hague Tradition remained essentially dormant through the mid-twentieth century. Early in thedevelopment of the draft rules that would become the 1977 Additional Protocols, the InternationalCommittee of the Red Cross undertook a codification and update of rules concerning the conduct ofhostilities formerly associated with the Hague Tradition. In particular, the 1977 Additional Protocolsaddress protection of civilians from the effects of hostilities. See Protocol I, supra note 33, arts. 51–58. R

348. COMMENTARY ON THE ADDITIONAL PROTOCOLS OF 8 JUNE 1977 TO THE GENEVA CONVENTIONS

OF 12 AUGUST 1949, at 32, ¶ 49 (Yves Sandoz et al. eds., 1988) [hereinafter Commentary]. The Com-mentary notes with respect to Article 1 that treaties of humanitarian law do not operate on the basis ofreciprocity—rather they are “unilateral engagements solemnly contracted in front of the world.” Id.



tively accede to the Protocol and induce reciprocal observance from de jureparties, thereby reducing the exclusionary effects of states’ insistence on for-mal obligational reciprocity.

Yet no Article explicitly requires non-reciprocal application of obliga-tions. Furthermore, states parties’ and signatories’ statements do not mirrorthe unofficial Commentaries’ enthusiasm for paragraph 5. Some states par-ties have interpreted Article 96 as preserving the principle of obligationalreciprocity.350 And the United Kingdom submitted with its 1998 ratifica-tion a reservation to two important provisions on protections of civilians intargeting. The UK reservation provides:

The obligations of Articles 51 and 55 are accepted on the basisthat any adverse party against which the United Kingdom mightbe engaged will itself scrupulously observe those obligations. If anadverse party makes serious and deliberate attacks, in violation ofArticle 51 or Article 52 against the civilian population or civil-ians or against civilian objects, or, in violation of Articles 53, 54and 55, on objects or items protected by those Articles, theUnited Kingdom will regard itself as entitled to take measuresotherwise prohibited by the Articles in question to the extent thatit considers such measures necessary for the sole purpose of com-pelling the adverse party to cease committing violations underthose Articles, but only after formal warning to the adverse partyrequiring cessation of the violations has been disregarded andthen only after a decision taken at the highest level of govern-ment. Any measures thus taken by the United Kingdom will notbe disproportionate to the violations giving rise there to and willnot involve any action prohibited by the Geneva Conventions of

349. Id. ¶ 51. Paragraph 51 includes the Commentary’s strongest rejection of conditions of reciproc-ity, stating:

The prohibition against invoking reciprocity in order to shirk the obligations of humanitarianlaw is absolute. This applies irrespective of the violation allegedly committed by the adversary.It does not allow the suspension of the application of the law either in part or as a whole, evenif this is aimed at obtaining reparations from the adversary or a return to a respect for the lawfrom him. (19) This was confirmed quite unambiguously in Article 60 of the Vienna Conven-tion on the Law of Treaties, which lays down under what conditions a material breach of atreaty can permit its suspension or termination; that article specifically exempts treaties of ahumanitarian character.

Id.350. Report of the Swedish International Humanitarian Law Committee Stockholm, supra note 188, at 601 R

(observing “Sweden shall not be required to abide by more comprehensive obligation than those applyingto our adversary”). The report expresses a preference for offering non-party enemies the opportunity toassent to practical observation of the Protocol by agreement. The Committee, however, reserved the rightto waive full application of the Protocol where an adversary fails to reciprocate. Id. at 602. Finally, theCommittee observed that provisions of the Protocol that had achieved customary status would berespected even in the absence of reciprocal observance. Id.



1949 nor will such measures be continued after the violationshave ceased.351

The Vienna Convention’s nonretroactivity provision would prevent para-graph 5 from operating on the UK and states expressing similar reservationsas a matter of conventional law with respect to Protocol I. The only remain-ing source for a prohibition on negative reciprocity and reprisal would becustom. Though framed as a question of reprisal rather than as one of nega-tive reciprocity, the reservation casts significant doubt on the customarystatus of paragraph 5 from the perspective of the United Kingdom.

Nevertheless, the Protocols’ expansion of the traditional scope of applica-tion of the Geneva Conventions demonstrates an intent to diminish the op-eration of negative reciprocity. Two provisions in particular mitigate theGeneva Conventions’ limits on application that preserved the effects of nega-tive reciprocity. First, the revolutionary and highly controversial Article 1,paragraph 4 extends the protections of Protocol I to armed conflict betweenstates parties and “peoples fighting against colonial domination and alienoccupation and against racist regimes . . . .”352 It thus applies a major por-tion of the law of war to armed conflicts with non-state actors in addition toconflicts between sovereign peer competitors. It also eschews obligationalreciprocity as the test for law of war applicability in favor of determiningapplicability on the basis of adversaries’ causus belli.

Second, in qualifying conflicts, Protocol I amends the traditional criteriafor Prisoner of War protection. Through a textually complex regime, Article44 awards POW status to all “combatants” who fall under the power of anadverse Party.353 With only one exception, individual combatants qualify forPOW status notwithstanding their failure to observe the law of war.354

Under Article 44, only failure to carry arms openly in the attack, or per-fidy,355 disqualifies combatants from POW status.356

The extent to which Article 44 reflects a sea change in POW status and arepeal of the vestiges of reciprocity is a matter of debate. The 1949 Conven-

351. Reservation letter from Christopher Hulse, Ambassador of the United Kingdom to Switzerland,to the Swiss Government (Jan. 28, 1998), available at http://www.icrc.org/ihl.nsf/NORM/0A9E03F0F2EE757CC1256402003FB6D2?OpenDocument.

352. Protocol I, supra note 33, art. 1, ¶ 4. R353. Protocol I, supra note 33, art. 44. R354. Article 44 states in relevant part, “While all combatants are obliged to comply with the rules of

international law applicable in armed conflict, violations of these rules shall not deprive a combatant ofhis right to be a combatant, or if he falls into the power of an adverse Party, of his right to be a prisonerof war.” Id.

355. Protocol I defines perfidy as “[a]cts inviting the confidence of an adversary to lead him to believethat he is entitled to, or is obliged to accord, protection under the rules of international law applicable inarmed conflict, with intent to betray that confidence.” Protocol I, supra note 33, art. 37. R

356. Protocol I, supra note 33, art. 44, ¶ 4. While captured fighters who failed to carry arms openly Rforfeit POW status, Article 44 provides that they remain protected by “protections equivalent in allrespects to those accorded to prisoners of war by the Third Convention and by this Protocol.” Id. Thus,combatant immunity appears to be the only forfeited protection.



tions had required group adherence to the law of war as a criterion for POWstatus, at least for militias and volunteer corps. A cursory read of Article 44suggests that it eliminates the requirement of observational reciprocity, ex-cept with respect to perfidy. Yet Article 44 cannot be read in isolation.Many fail to appreciate that the operative term for POW status under Arti-cle 44 is “combatant,” a term defined in the preceding Article.357

Article 43 offers a two-stage definition of combatant, curiously presentedin reverse order. Article 43(2) defines combatants as “armed forces of a Partyto a conflict (other than medical personnel and chaplains . . .).”358 Article43(1), defines “armed forces” to include “all organized armed forces, groupsand units which are under a command responsible to [a] Party . . . . [and]subject to an internal disciplinary system which inter alia, shall enforce com-pliance with the rules of international law applicable in armed conflict.”359

Were the term “combatant” loosely understood to mean “persons takingpart in hostilities,” the consternation over Article 44 might be justified.Allowing anyone who took up arms openly to benefit from POW statuswould upend the law of war’s detention regime and would call into questionwhether states could still demand obligational and observational reciprocitygiven such permissive criteria. But as Article 43 reflects, “combatant” is aterm of art in Protocol I. As feared by detractors of Protocol I, individualcombatants retain POW status despite their personal law of war viola-tions.360 Article 43 preserves both obligational and observational reciprocitywhere it counts: at the group level. It ensures that only combatants whobelong to “armed forces, groups, and units” that actually commit to, apply,and enforce the laws of war are eligible for POW status.

Thus while Protocol I amended the test for POW status, states retainedthe critical guarantee that only groups of adversaries committed to recipro-cal obligation to and observance of the law of war would benefit from thestatus. Protocol I’s limitations and states’ reservations to provisions evensuggesting unconditional application undermine the claim that Vienna Con-vention Article 60, Paragraph 5 reflected or matured into customary law.The Convention’s prohibition on retroactivity thus bars applying Paragraph5 to earlier law of war treaties.

Finally, the Protocols’ efforts to reform the law applicable to non-interna-tional armed conflicts demonstrate states’ commitment to preserving reci-procity in the late twentieth century. 1977 Additional Protocol II updatesand supplements the protections prescribed in Common Article 3 of the1949 Conventions. Protocol II adds to Common Article 3, inter alia, ex-

357. Article 44 explicitly refers to Article 43 for the definition of the term “combatant.” Id. art. 44.358. Id. art. 43(1).359. Id. art. 43(2).360. Recall that the 1949 Third Geneva Convention operates similarly through Article 85, permit-

ting POWs to retain the benefits of the Convention even while facing prosecution for war crimes. 1949Geneva Convention III, supra note 155, art. 85. R



panded process in criminal prosecutions,361 enhanced responsibilities withrespect to the wounded and sick,362 and added details to protections fromthe effects of hostilities.363 Yet while it expanded substantive protections,Protocol II restricted the scope of application of those protections to be con-sistent with the rules of international armed conflict. Article 1(1) limitsapplication of Protocol II to conflicts between states parties and armed forcesor groups “under responsible command . . . as to enable them to . . . imple-ment this Protocol.”364 Thus only conflicts between states and groups com-mitted and able to reciprocate observance of Protocol II trigger itsprotections. In this respect, some states regarded Article 1 as a step back-ward for the law of non-international armed conflicts.365 However, armedwith an appreciation of the persistence of negative reciprocity in the law ofwar, one is less surprised to find states willing to reverse a trend of expandedapplication to preserve reciprocity.

C. Political and Military Context

The shared political-military context of the Vienna Convention and theAdditional Protocols casts doubt on the extent to which states envisionedthe actual operation of Article 60, paragraph 5, as well as its customarystatus. States negotiated, concluded, and widely ratified both the ViennaConvention and the Additional Protocols in an era when nuclear weaponsdominated military strategy. Indeed, just as representatives to the Diplo-matic Conference set out to draft the Protocols to the Geneva Conventionsin 1974, U.S. nuclear strategy abandoned its emphasis on limited strikes infavor of “Assured Destruction.” In response to advances in Soviet nucleardelivery capacity, Secretary of Defense Robert McNamara committed theUnited States to developing the capacity to launch a second strike capable ofdestroying twenty to twenty-five percent of the population of the SovietUnion’s largest cities.366

Such plans were almost entirely incompatible with the Protocols’ nascentlimits on targeting.367 The ICJ acknowledged as much in its equivocal 1996advisory opinion on the legality of nuclear weapons under the law of war and

361. Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protec-tion of Victims of Non-International Armed Conflicts (Protocol II), June 8, 1977, 1125 U.N.T.S. 609.

362. Id. Part III.363. Id. Part IV.364. Protocol II, supra note 361, art. 1(1). R365. Letter of Transmittal from Ronald Reagan, U.S. President, to the United States Senate and State

Department, reprinted in 81 AM. J. INT’L L. 910–12 (1987) (including analysis and commentary onProtocol II).

366. See David Alan Rosenberg, Nuclear War Planning, in THE LAWS OF WAR, supra note 124, at 180 R(noting U.S. shift in nuclear target planning from Soviet nuclear force or military targets to urban-industrial centers).

367. The ICJ later took up the issue of whether nuclear weapons comply with the law of war. See PaulKahn, Nuclear Weapons and the Rule of Law, 31 N.Y.U. J. INT’L L. & POL. 349 (1999).



human rights law.368 The NATO powers reconciled their plans with theProtocols by an appeal to exceptionalism. Many NATO states insisted thatnuclear weapons be regulated separately from conventional weapons.369 Theassumption was that use of nuclear weapons, or a non-nuclear attack of suffi-cient scale to provoke self-defense using nuclear weapons, would occasion alarge-scale and reciprocal suspension of much of the law of war.

Cold War nuclear exceptionalism indicates states’ extraordinary commit-ment to conditions of reciprocity. The explicit carve-outs for nuclear ex-changes are in some respects equivalent to anticipatory negative reciprocity.Although nuclear exchanges are commonly understood to constitute repri-sals, they more closely resemble suspension or even termination of the entirenorm in question—distinguishing characteristics of negative reciprocity.The nuclear example thus further undermines the claim that reciprocity hasbeen eliminated as a condition of observance of the law of war.370

A dispositive determination of the customary status of paragraph 5 re-mains elusive. Indicia of state practice with respect to security efforts andparticularly the conduct of hostilities are closely guarded. But claims thatparagraph 5 reflected customary law at the time of its drafting or that itmatured into custom at some later point suffer from an oversimplified un-derstanding of reciprocity under the law of war.

The developers of the law of war did not clearly address the role of reci-procity in the instruments that followed the Vienna Convention. Proponentsof paragraph 5 likely overstate its conventional effects and customary status.In short, reciprocity remains an underdeveloped consideration within thediscussion of how to apply and revise the law of war. With a more completeunderstanding of reciprocity’s persistence in the law of war, some prescrip-tions that may guide efforts to apply and reform the law become apparent.

V. CONCLUSION: RECIPROCITY, THE LAW OF WAR, AND

PRESCRIPTIVE CONSIDERATIONS

To some extent, state practice vindicates the claim that states’ insistenceon reciprocity has subsided over time. Practice has mirrored the positivelaw’s shift toward a more subtle doctrine of reciprocity. Despite enduringtextual authority to do so, states have not frequently exercised negative reci-procity under the law of war. Invocations of the Hague Regulations’ si omnesclause are effectively extinct.371 The Geneva Conventions have rarely, if ever,

368. See id.369. George Bunn notes that the U.S. signature of Protocol I included the understanding that the

rules established by the Protocol were not intended to have any effect on and do not in fact regulate orprohibit the use of nuclear weapons. George Bunn, U.S. Law of Nuclear Weapons, NAVAL WAR C. REV.46, 58 (1984).

370. See supra discussion accompanying notes 108–16. R371. See supra discussion accompanying note 213. R



been deemed inapplicable on the basis of an adversary’s failure of observa-tional reciprocity.

Yet states have regularly resorted to secondary rules within the law of warto vindicate the same concerns that informed traditional reservations or exer-cises of negative reciprocity. As the preceding analysis has shown, twentiethcentury law of war instruments lacking express conditions of reciprocal ob-servance or obligation have included restrictive conditions on applicationand scope that vindicate the same concerns. States have held fast to thesesecondary rules as conditions on the de jure application of the law of war.372

While they have admitted that some law of war provisions apply to situa-tions and persons who do not meet the sovereign-focused criteria of thetraditional law, states have also been careful to characterize such applicationsas policy-based or gratuitous extensions and not de jure operations of thelaw. The categorical claim that reciprocity no longer conditions the opera-tion of the law of war is greatly overstated and fails to appreciate how othersecondary rules act as proxy or ersatz conditions of reciprocity.

Military historian Martin van Creveld has argued that “what is and is notconsidered acceptable behavior in war is historically determined, neitherself-evident nor unalterable.”373 The reactive nature of the law of war con-firms in many respects Crevald’s analysis. It is now axiomatic that, to beeffective, the law of war must account for both the operational demands ofarmed conflict as well as contemporary notions of humanity. Historically,allegations that the law of war is out of touch or irrelevant have indictedprovisions that overly burden military operations or do not adequately ac-commodate states’ security needs. Such provisions have withered from disuseand even disdain.374 However, if the laws of war have been unresponsive tomilitary necessity, they have also failed to keep pace with our evolving senseof humanity and decency.375 War rules that are out of touch with modernconceptions of humanity, justice, and human rights present as great a threatto effectiveness and the rule of law as rules that fail to adequately account formilitary necessity.

The law of war has proved a relatively dynamic body of law, periodicallyevolving to balance conceptions of military necessity against maturing ex-

372. Professor Geoff Corn highlights three recent examples in which the United States has cited strictapplication provisions, including those of Common Article 2 of the 1949 Geneva Conventions, to denythe operation of the full body of the law of war. Geoff Corn, Hamdan, Lebanon, and the Regulation ofHostilities: The Need to Recognize a Hybrid Category of Armed Conflict, 40 VAND. J. TRANSNAT’L L. 295,303–11 (2007).

373. Martin van Creveld, The Gulf Crisis and the Rules of War, 3 MIL. HIST. Q. 23, 23 (1991).374. See The League of Nations and the Laws of War, 1 BRIT. Y.B. INT’L L. 109 (1920–21); Scott R.

Morris, The Laws of War: Rules by Warriors for Warriors, THE ARMY LAWYER 4 (Dec. 1997). Major Morrischronicles the involvement of military officers in the development of the laws and customs of war leadingup to and including the 1863 Lieber Code. Morris argues that their influence ensured the relevance andeffectiveness of these rules on the battlefield. Id.

375. For example, the ambiguous and permissive principle of proportionality may be ripe for recon-sideration because some may consider it out-of-touch with modern sensibilities.



pectations of humanity in war. Yet the role of reciprocity remains underap-preciated as a factor for consideration. As a critical element of both early andextant war conventions, reciprocity warrants deliberate scrutiny to deter-mine whether it fulfills current military needs. As Crevald’s observationsuggests, the future role for reciprocity should depend not on its pedigreebut rather on whether it remains consistent with notions of modern militarynecessity and humanity.

While law of war reformers have cited evolving standards of decency andhumanity as well as the changing nature of states’ adversaries, few havegazed inward to inquire whether changes in states’ own military doctrineand operations call for humanitarian revisions of the law. Most discussionsfocus on how changing external threats challenge or should provoke changein the law. Thus efforts to humanize humanitarian law have leveraged in-creased awareness of the human costs of conflict and the tactical and strate-gic challenges presented by asymmetrical foes. Yet there has been littleanalysis of whether states’ own military concerns might provide impetus forfurther evaluation or humanization of the law. If vestiges of negative reci-procity persist in the law of war, they should be scrutinized to determinetheir relevance and compatibility with military doctrine and strategy. In afollow-on piece that leverages the framework identified by this Article, Ihope to highlight such normative issues concerning the persistence ofreciprocity.

Recent developments in states’ military strategies and doctrine necessitatea critical examination of the propriety of reciprocity’s persistence in the lawof war. Greater appreciation of the importance of public support for militaryoperations and a revival of counter-insurgency doctrine may cast doubt onthe propriety of negative reciprocity as a measure of state self-help. Counter-insurgency strategy’s emphasis on political over military considerations cre-ates the possibility of new coincidences of interest between military doctrineand humanity.376

More importantly, counter-insurgency strategy counsels states and theirarmed forces to know themselves. Sir James Graham declared in 1849 thatthe principle of reciprocity made “the interest of others the measure of our

376. DEP’T OF THE ARMY, FIELD MANUAL 3–24, COUNTERINSURGENCY OPERATIONS 1–19 (Dec. 15,2006). Field Manual 3–24 observes, “The primary objective of any [counterinsurgency] operation is tofoster development of effective governance by a legitimate government. Counterinsurgents achieve thisobjective by the balanced application of both military and nonmilitary means.” Id. Of course, currentcounter-insurgency strategy is not the first or only observation of the alignment of interest betweenmilitary necessity and humanity. For example:

On May 18, 1859, at Marengo, Marshal Regnaud de Saint-Jean d’Angely addressed thesewords to the Imperial Guard: ‘Soldiers of the Guard, . . . you will give the army an example offearlessness in danger, of order and discipline on the march, of dignity and restraint in thecountry in which you are engaged. The memory of your own families will make you consider-ate of the people of the country and will keep alive your respect for property, and you may besure that victory awaits you.

DUNANT, supra note 165, at 42, n.1. R



interest . . . it makes the folly of others the limit of our wisdom.”377 In fact,long before Graham, Sun Tzu counseled leaders to “[k]now your enemy andknow yourself.”378 It may be no small irony that categorical insistence onreciprocity distracts us from accomplishing the latter. Military and politicalplanners appear to better appreciate the relationship between why they wagemilitary operations and how they wage them. The prominence of Rule ofLaw or Stability Operations in modern doctrine emphasizes a new conscious-ness about integrating the day-to-day conduct of operations with their de-sired end state.379 Such operations call on states not only to foster respect forthe rule of law in developing states but also to examine their own relation-ship to the law.380 Thus, whether insistence on reciprocity complements orretards the execution of emerging military strategy deserves criticalexamination.

Outing reciprocity in both the preterit and extant law of war does notaddress the entire spectrum of challenges facing the law. However, an un-derstanding of the law of war that explicitly considers reciprocity may focusdebate over law of war reform into a more fundamental conversation aboutthe appropriate role of reciprocity in regulating the conduct of hostilities.The appreciation of negative reciprocity in the law of war offered by thisArticle provides a much-needed platform for such reform discussions.

377. 104 PARL. DEB., H.L. (3d ser.) (1849) 662.378. SUN TZU, THE ART OF WAR 84 (Samuel B. Griffith trans., Oxford at the Clarendon Press 1963)

(6th Century B.C.).379. DEP’T OF THE ARMY, FM 3–07 STABILITY OPERATIONS 3–1 to 3–2 (Oct. 6, 2008). The FM

(“Field Manual”) observes, “Essential stability tasks lay the foundation for success of the other instru-ments of national power. This foundation must sustain the burdens of governance, rule of law, andeconomic development that represent the future viability of a state.” Id.

380. See Sarah Sewall, Remarks at Rule of Law Conference at TJAGLCS (Sep. 24, 2006) (notes on filewith author).

Reciprocity and the Law of War - Harvard International Law ... · Reciprocity and the Law of War...

Documents

Transcript of Reciprocity and the Law of War - Harvard International Law ... · Reciprocity and the Law of War...