Occupation of Japan

7/29/2019 Occupation of Japan

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Regular Course1946-1947

The Occupation of ' Japan

Type of' Operation Described: Demilitarization of ' Japan's ArmedForces by Units of' Sixth Army.

Lt. Col. W. C. Wickboldt, Inf'antry

The occupation of' Japan, by L't Co] .L: C.Wic kb oldt, Inf. Command and Staff' College1946-47.

This DocumentIS A HOLDING OF THE

ARCHIVES SECTIONLIBRARY SERVICES

FORT LEAVENWORTH, KANSASDOCUMENT NO. N-2253.43_ COPY NO. J.

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COW' AND AND STAFF COLLEGEFORT LEAVEN J ORTH

KANSAS

School of Combined ArmsRegular Course

1946-1947

The Occupation of Japan(

Type of Operation Described:Forces by Unite of Sixth Demilitarization of Japan's ArmedArmy. \

Lt. Col. ; . C. Wickboldt, Infantry'

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Table of ContentsIndex 1Bibliography 2Introduction 3Blacklist Operation 4Field Order #75, Hdqrs. Sixth Army 5Geographical Features bMilitary Aspects of Zones of Occupation 7The Advance Party8The Landings 9Operations of a Typical Regiment 10Conclusions 11Lessons Learned 12Meap: JAPAN Situation Map A, L 844 C & S College Sketch Japan


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BIBLIOGRAPHY

A-1 Sixth U. S. Army Report of the Occupation of Japan.22 September 1945- 30 November 1945.A-2 The World Almanac- 1946.A-3 Occupation of Japan and Japanese Reaction-MilitaryReview Vol. XX\TI June 1946-No. 3.


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INTRODUCT ION

The purpose of this monograph is to cover the execution ofOperation Blacklist by units of Sixth Army. The following politicaland m ilitary background is cited to facilitate an understanding ofthis unprecedented operation.

The Cairo Conference of November 1943 and The Potsdam Proclama-tion of July 1945 set the political stage for the surrender of Japan.At the Cairo Conference th e Big Three (United States, Great Britian,China) resolved to fight the war in the Pacific to th e unconditionalsurrender of Japan, stripping Japan of all her outer possessions.(1) At the Potsdam Conference, President Truman called upon th eJapanese Government to surrender unconditionally and provided fo r th eoccupation of Japan at localities to be selected by the SupremeAllied Commander.

The formal surrender document signed aboard the battleship Miissouri2 September 1945 approved the retention of the Emperor as head of theJapanese Government, subject to the Supreme Commander for the AlliedPowers who was empowered to take such steps as he deemed proper toeffectuate the terms of surrender. (2)

In the Phillipines, the Luzon Campaign was terminated on the30 June 1945, and the U. S. Sixth Army initiated planning and prepara-tions for the Amphibious assault upon the southern coasts of Kyushu.Known as Operation Olympic with a target date of 1 November 1945. (3)On 2 August 1945, four days prior to the bombing of Hiroshima, astaff study for Operations Blacklist was received at HeadquartersSixth Army. (4) The study outlined general missions for the Occupationof Japan in the event of sudden capitulation and imposed an additionalplanning mission upon the headquarters staff. At this time th epreparations for the invasion of Kyushu had been progressing for overa month. Units were either at or enroute to final staging areas,assault units were undergoind amphibious training, and supplies werebeginning to accumulate. Jungle worn equipment was being replacedby woolen uniforms for warfare in a cold, wet climate. Training inthe use of the recoiless rifles, the sniper scope, and other equip-ment not previously available was being emphasized. Such was th ebackground, political and military, when AFPAC's staff study for theBlacklist Operation was received on 2 August.

(1) A-2, p 108; (2) A-2, p 109; (3) A-l, p 9; (4) A-l, p3


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Blacklist OperationThe plan dor Operations Blacklist called for the occupation

of Korea by th e Tenth Army, of Hokkaido and Northern Honshu by th eEighth Army, and of Western Honshu, Shikoku, and Kyushu by th eSixth Army. Major forced assigned to the Sixth Army for th eoccupation were I Corps, X Corps, and V Amphibious Corps which,together with supporting units, totaled 240,000 troops. The generalmissions assigned to the army commanders directed the rapid occupa-tion of strategic center in order to isolate Japan from Asia, seizecontrol of the higher echelons of government, immobilize the enemyarmed forces, and initiate operations against any racalcitrantelements in Japan or Korea. Once initial control had been firmlyestablished, each commander was to assume responsibility for:a. The demobilization of the Japanese Army.

b. Institution of m ilitary government.c. Recovery of Allied prisoners of war.d. Extension of such control over the Japanese as

was required to implement the post-war govern-ment and aid th e armies of occupation.e. Insurance that th e terms of surrender were

carried out. (5)In general, swift occupation of the selected strategic centersat th e earliest possible date after surrender, decentralization of

planning and operations within major commands, and instant readinessto meet armed resistence at the time of or subsequent to the initiallandings were to characterize the operation.

Since there was no indication that Japan would surrender priorto actual initiation of the Kyushu invasion, preparatory activitiesincident to an assault and invasion continued without interruption.Concurrently, however, work was initiated to prepare troop lists,determine supply requirements, gather intelligence, and determinemore specifically th e role the various staff sections were to assumein execution of special tasks such as demilitarization and demobili-zation of the Japanese Armed Forces, military government, etc.

The destruction of Hiroshima on 6 August 1945 by a singleatomic bomb and the entry of Russia into the war increased thepossibility of early surrender to such an extent that planning forthe occupation was still further intensified, although planningfor th e Kyushu invasion did not cease. After the initial reportof the Japanese offer to surrender on 10 August, however, furtheraction on th e Kyushu Operation was deferred, and preparations fo rth e occupation were accelerated accordingly.

Following th e official announcement of the Japanese offer tosurrender on 15 August, GHQ, AFPAC, officially suspended the KyushuOperation and issued a warning order to initiate the occupationof Japan. (6)

(5) A-1 p 10; (6) A-1 p 11.


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Field Order #75, Hdors. Sixth ArmyField Order 75 Headquarters Sixth Army, dated 21 August 1945,

assigned zones and missions to its major subordinate commands asfollows:1. I Corps (25th, 33nd, 98th Divisions,) Nagoya-Osaka-Kyotoarea of central Honshu.2. X Corps, (24th and 41st Divisions,) Kure, Okayama area ofSouthern Honshu and the island of Shikoku.3. V Amphibious Corps (2d Marine Division, 5th-32nd Division)Kyushu and the Shimonoseki area of Western Honshu. (7)

(7) A-l, p 12


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Geographical FeaturesBriefly the zone of occupation assigned to Sixth Army extended

over 46,000 square miles, including the islands of Kyushu, Shikoku,an d the western half of Honshu. Larges t and most important of thethree areas was Western Honshu with the cities of

(1) Nagoya (population l,328,084)--Aircraft, Textile manu-facturing center

(2) Osaka (Population 3,252,340)---Industrial Center(3) Kobe (population 967,334) -- Port(4) Kyoto (population l,039,726)---Resort(5) Kure (populat ion 276,085)-N----aval BaseNext in importance was Kyushu with a population of ten million

spread among its 15,000 square miles of precipitous mountains.Chief of the cities are:(1) Nagasaki (popultion 252, 633)--Shipbuilding Center

(2) Sasebo (population 205,980)--Ship repair base(3) Yawata--4ocation' of Imperial Iron ahd Steel Works(4) Kagoshima--Principal Port

Leas t impor tant of the t2hree islands is agricultural Shikoku,which is characterized by rugged sharp-sided mounta ins and narrow,deep,winding valleys, and which has a population of about3,300,000 people. (8)

(8) A-1, p 5


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Military Aspects"Of the 1, 600,000'Japanase ground force troops stationed

in Japan at the termination of hostilities, 850,000 (comprising theSecond General Army) were located in the Sixth Army area of oc-cupation. In all, this area could muster 24 infantry divisions,6 depot divisions, and 10 independent mixed brigades. In addition,there were 120,000 army air personnel, 110,000 personnel of theShipping Command, and 30,000 railway troops, giving a grand totalof approximately 1,000,000 military personnel in all th e area whichwas to be occupied by the Sixth Army troops." (9)

(9) A-l, p 6


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The Advance PartyAfter the formal surrender of the Japanese on 2 September,

radio communications had been established between HeadquartersSixth Army on Luzon and the Second Japanese General Army, whichcontrolled that area of Japan to be occupied by the Sixth Army.In order to assure the smoothe and orderly entry of Sixth Armyforces into Japan, an advance echelon was organized to precede th etroops and obtain information of the situation in th e area to beoccupied. The advance party consisted of 19 officers and 2 en-listed men, representing each of th e General Staff Sections aswell as Medical, Engineer, Finance, M ilitary Police, M ilitaryGovernmrent, Signal Procurerment, Trahsportation, Quartermaster,and Headquarters Commandant Sections. Similar advance partieswere organized for I Corps, X Corps, and VAC.

After the arrival of the Advance Party at Wakayama on20 September a meeting was arranged with the Chief of Staff of th eSecond Japanese General Army who was instructed to :

(1) Clear the Japanese armed forces, except for unarmedcaretaking personnel, from those locations where ourtroops were scheduled to land.

(2) Prohibit th e movement of Japanese armed forces oncertain highways.(3) Restrict th e movement of civilian traffic on thedates and in the areas of the several landings.

(4) Direct th e establishment of contact by the appropriatesenior subordinate Japanese commander with the I and XCorps and VAC in their respective areas, including ini-tial contact with respective advance parties.

(5) Direct the immediate establishment of liaison with theAdvance Party at Wakayama and later with HeadquartersSixth Army at Kyoto.

This me ting was quite formal and impressive and started manyprocesses n essary to accomplish the occupation and also had the ;effect of serving notice on the Japanese Army that the Allied Forcesknew exactly what they wanted and had organized their plans well.

Later additional directives required the Japs to report thelocation and amounts of their ordnance material; amounts and placesof storage of chemical warfare material; amounts and locations ofcertain engineer supplies; and ordered the establishment of directliaison with Japanese civilian government officials, the JapaneseImperial Railways, the Japanese banking system, medical organizations,communication facilities, and other Japanese activities of specialinterest.

In each prefecture the Japanese established a liaison officerwho assisted the Home Ministry Governor in carrying out militarydirectives. These liaison officers were quite efficient in achievingresults. (10)

(10) A-l, p 23


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The LandingsOn 21 September representatives of the Fifth Fleet closely

inspected the Sasebo coastal area for possible Japanese reactionagainst VAC landings, particular attention being paid to localitiessuitable for suicide craft. After a thorough survey of the entirecoastal area surrounding Sasebo in which no craft of offensivepotentialities were seen, the Navy deemed the harbor safe fo r entry ofth e 5th Marine Division.

Following a month of continued intensive planning and preparationthe V Amphibious Corps inaugurated occupation by landing the 5th MarineDivision at Sasebo on 22 September and the 2d Marine Division atNagasaki on the following day. Later landing of the 32d Division atSasebo on 15 October enabled the Corps to extend its control over allKey areas in its assigned zone which included Kyushu and th e south-western tip of Honshu. Successive landings on Honshu of th e 33d Di-vision at Wakayama on 25 September, the 98th Division at Wakayama on27 September, and the 25th Division at Nagoya on 25 October effectedoccupation of the I Corps area. The X Corps completed the occupationwith the 41st Division at Kure on 6 October and the 24th Division onShikoku on 22 October.

The original plan contemplated the accomplishment of the occupa-tion mission in three phases.Phase I landings by V Amphibious Corps in th e Sasebo-Nagasaki

area, and by I Corps in th e Kobe-Osaka area.Phase II called for landings at a later date by I Corps atNagoya and th e overland movement of a V Corps unit to Fukuoka.Phase III envisioned an overland movement by I Corps to Tsurugaand landings by X Corps at Kure, Kocki, and Okayama.

Basically this plan provided for th e establishment of control ofJapanese Armed Forces and Civil population; th e imposition of prescribedterms of surrender by occupying Key areas such as Nagasaki, Sasebo, andOsaka; and the extension therefrom of occupation and control as troopsbecame available during phase II and III.

During the early days of the occupation a number of reasonsinduced the abandonment of th e phase concept just described. Forinstance, the attitude of th e Japanese people, the complete capitulationof th e armed forces, and the cooperation of Japanese authorities facili-tated initial control and disarmament so that the operations evntuallybecame a movement of troops into areas that were awaiting occupationand that were prepared for our surrender policies. Furthermore th euncertain conditions of mined harbors, the effect of typhoons in land-ing areas, and the availability dates of shipping disrupted the originaltiming of landings to such an extent that there were no distinguishablephases in the operation; in one case Phase III landings in X Corps areapreceded Phase II landings at Nogaya contrary to original plans. (11)

(11) A-i, p 24


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Operations of a Typical Regiment"The infantry regiment was, in the occupation of Japan, th e

chief instrument of demilitarization and control. The entire planfo r the imposition of the terms of surrender was based upon thepresence of infantry regiments in all of the prefectures within th eJapanese homeland and in Southern Korea." (12)

The following is an analysis of th e actions of a typicalregiment accomplishing its occupation mission. Soon after landingat Matsuyama, Shikoku on 22 October, the 19th Infantry Regiment ofthe 24th Infantry Division moved by rail and motor to the principalcity of Kochi, in th e center of Kochi prefecture. Divisional Mili-tary Government personnel preceded th e unit by twenty-four hours andarranged for billets in Jap Military Barracks near th e city. Duringthe establishment of the troops in their new bivouacs, regimentslstaff officers studied available Japanese operational maps and at aspecial conference with senior Jap naval and military commanders inthe zone, the details of the execution of demilitarization weredetermined. It was surprisingly learned that the Japs had alreadydemobilized agout eighty per cent of their forces prior to ourarrival. Only necessary caretaking personnel remained to securelarge dumps of military supplies. The Japanese furnished us voluminouscopies of inventories of all classes of supplies. Detailed operationalmaps indicated the almost inaccessible locations of fixed, heavyartillery and underground stores.

Verification of the locations of installations was made bynumerous patrols and spot checks revealed a high degree of accuracyof inventories. With this information the regimental commander wasready to carry out his responsibility of supprvising the executionof the surrender terms. He was particularly charged with (1) seizingall Jap armed force installations and th e disposition of all materialtherein; (2) the security of all enemy stores not subject to immediatedisposition, and (3) the supervision of demobilization of Japanesearmed forces when their services were no longer required for maintenanceof captered arms and material.

Based on an equal number of large dumps in each area th eregimental zone was subdivided into battalion zones which were furthersubdivided with individual companies going to their assigned areasto initiate demilitarization. In some instances companies moved largequantities of arms and ammunition from inland mountain supply duppsthat were inaccessible to trucks. Other units located near the beacheswere confronted with naval armament such as submarines, suicide craft,and large torpedoes.

The infantry company was the working unit which actually ac-complished the destruction or consignment of material, or the demo-bilization of Japanese Armed Forces that remained within the companyzones. The company commander was empowered to seize installationswithin his zone and, with the use of available Japanese army personnelnot yet demobilized and laborers obtained through the Japanese HomeMinistry representative in his area, either destroy or turn over to theJapanese Home Ministry all materiel within the installation. U. S. Armypersonnel were used only to supervise this work and to see that completedestruction was accomplished.

The company commander disposed of material in accordance withprocedures outlined by higher headquarters. All materiel fell in th efollowing categories: that to be destroyed or scrapped (explosivesand armament not needed for souvenirs or training purposes were chiefitems: that to be used for our operation (telephones, radios, andvehicles); that to be returned to the Japanese Home Ministry (fuel,lumber, etc.); that to be issued our forces as trophies; or that to beshipped to the U. S. for training purposes or as war trophies.Material not marked for destruction was disposed of by prescribedmethods. Japanese labor hauled explosives aboard Japanese trucks toapproved burning areas, or if the installation was located near a deepsea waterway th e explosives were dumped at sea. (13)(12) A-l, p 35; (13) A-i, p 36 -10-


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Conclusions

Physical control of the zone of responsibility provedremarkably easy, fo r the Japanese were compliant and cooperative.The absence of casualties indicated the complete capitulation ofthe Japanese Armed Forces and civil population. The terms ofsurrender were carried out efficiently and without incident orinjury to occupation troops. At the close of the period,30 November, demilitarization of Japan had progressed so satis-factorily that some regiments which had completed their assignedmissions were able to withdraw to bivouac areas fo r training andrehabilitation. Because of their disciplined loyalty fo r th eEmperor, the armed forces of Japan faithfully obeyed Allieddirectives for demilitarization.

An estimate of the number of American lives that were sparedby the substitution of Operation "Blacklist" for th e operation"Olympic" is best illustrated by a quotation from Major GeneralWilloughby, G-2 AFPAC:

"The enormous initial military risks of landing with tokenforces on the Japanese mainland, into a collossal armed camp, th eobvious gamble of landing with only two and a half divisions,confronted by sixty-four Japanese divisions, thirty-six brigadesand forty odd regimehts, were apparently not fully appreciated.All possible landing areas, in the event of American armedlandings, were completely orggnized by the Japanese Army andeach one of these areas had the potentiality of another Okinawa.There were perhaps five or six such areas, along the East .Coastof Japan--Kyushu, Shikoku, the Kanto Plain, the Sendai Corridorand others. The Japanese General Staff had enough divisions andbrigades to make an attack expensive everywhere. At Okinawa,from two to two and a half Japanese divisions exacted a total ofapproximately 40,000 American casualties on land, not to mentionthe shattering "KAMIKAZE" attacks on the Fleet. This affords acompletely authentic yardstick to forecast what it would havetaken in losses had we gone in shooting. The sinister ratio that26 Jap divisions exact 40,000 casualties spells:Location No. Divisions CasualtiesKYUSHU 13/14 Divisions 200,000SHIKOKU 4/5 " 80,000KANTO 22 " 400,000SENDAI 2 " 30,00

Total 710,000The conclusions are inescapable:!" (14)

A-3, P 3


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Lesson Learned1. There was a need for more complete and accurate intelli-

gence concerning conditions in Japan. Engineer, Trans-portation, and Signal planners had a difficult time gaugingcapacities in, Japan. M ilitary Government Personnel werevery much surprised to find an effective, efficient andcooperative Japanese Government system.

2. Timely issuance of Staff Studies and Warning Orders byHigh Headquarters enabled subordinate Headquarters toeffectively execute operations.

3. Occupation forces should not plan upon using demobilizedenemy specialists in disposition of Technical Material--nor should they be confronted with a large scale demobili-zation of their own forces by a Readjustment Program.

4. Disposition of material was delayed pending decisions asto requirements of technical intelligence, museum andmemorial pieces, operations, trophies.

5. The prevalence of naval mines made dumping materials atsea a hazardous and slow process.

6. The creation of U. S. Navy and Air Force liaison groupswas necessary to provide technical advice and assistanceto ground force troops.

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