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WW 2 History Club

24 - Aug - 2011

The The BombBomb

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Topics

1. Technology and Creation

2. Competitive Development Elsewhere

3. Military Situation in 1945

4. Political Situation in 1945

5. Alternatives

6. July,1945 (Potsdam, the test, final prep)

7. August,1945 (bombs dropped, Japan surrenders)

8. Immediate Effects

9. Current Views

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Technology & Creation1. Einstein’s early theories suggest incredible power release (E=mc2 )2. Szilard: chain reaction, large bomb (tons of fissionable material required)3. Einstein/Szilard letter to FDR4. Briggs Committee (US): slow and ponderous; not focused on weapons5. Frisch–Peierls Memorandum: small bomb (just lbs of fissionable material) feasible6. MAUD Committee (UK): urgent -- UK at war; focused on weapons7. NDRC collaboration with UK8. Manhattan Project: the real initiative

Initiated before scientists were “sure” it could be done Oak Ridge (uranium enrichment) Hanford (plutonium production) Uranium vs Plutonium “Gadget” test: New Mexico, July 1945

9. B29: Nov 1943: Operation Silverplate 509th Composite Group (led by Tibbets) formed to

train for the drops British Lancaster would require fewer mods but crews,

parts, maintenance would have been a large problem.

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The Manhattan Project:Los Alamos,

NM

The Manhattan Project:Los Alamos,

NM

Dr. Robert Oppenheimer

I am become death,

the shatterer of worlds!

I am become death,

the shatterer of worlds!

Major GeneralLesley R. Groves

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Manhattan Project Numbers

1. 3 years duration2. 30 sites (Oak Ridge, Hanford and Los Alamos are best known)3. 130,000 people4. $2 billion (~ $25 billion today)5. 90% to produce fissionable materails6. 10% on the actual weapons7. 2 different type of bombs

Uranium Relatively simple “gun type” bomb One bomb initially

Plutonium More complex “implosion type” bomb Three bombs initially (one used in test)

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Competitive Development

1. Britain Ahead of the US in the 1930s and early 1940s More focused on a bomb than on heat and power Frisch–Peierls Memorandum (aircraft delivered bomb

possible) Lots of good people (many who fled Germany) but

lacked the necessary resources to develop a bomb within the perceived timeframe of WWII

Collaboration with the US was the most productive course

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Competitive Development

2. Germany Hitler did not want “Jewish Science” (initially) Very capable scientists; several who made significant

contributions Anti-Semitic policies caused many scientists to flee Germany Germany had one of the few sources of uranium Werner Heisenberg led effort for several years Heavy water was selected as the reactor control medium The German attempt to build a reactor was feeble & disorganized Their effort to build an atomic weapon was nonexistent partially

because they continued to believe that the amount of fissionable material was several tons.

BUT Allies did not know precisely what German’s

capabilities were After the war

Heisenberg suggested that he purposely mismanaged project(s). Conversations taped while Heisenberg was under arrest suggest that

he did not fully understand bomb mechanics

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Competitive Development

3. Japan Leading scientist was Dr. Yoshio Nishina; well regarded Cyclotron work in 1930s Recognized potential for nuclear weapon in 1939; worried that US

was already pursuing No real weapons program until 1941 March 1943: Japan concluded that task was to large for even the

US; major effort refocused on radar and other technologies Ni-Go Project: Army continued to pursue atomic weapon; some

progress but bombed out of existence in 1945 F-Go Project: another Navy effort; some progress but way short of

actual weapon … After the war:

Weapons Test Rumors: that F-Go project had conducted a test in 1945 at Konan Camp, Korea

Repeatedly debunked, but the rumors persist.

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Military Situation – Summer 1945

1. War in Europe is over; Allies can now focus on Japan, but …

2. War in Pacific gets more deadly every day; Okinawa was a blood bath

3. Advantages of US island hoping strategy decay as we near Japan

4. US kill ratio declining5. Japanese Navy virtually eliminated, but

Kamikazes still a real threat6. Japanese army is still large, powerful and

determined

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Political Situation – Summer 1945

1. US tired of war; running out of draftees

2. Russia flexing its muscles

3. Most major Japanese cities destroyed

4. Most major Japanese industries destroyed

5. But Japanese “will to resist” unchanged

6. Japanese military in control

7. Defeat is unacceptable to Japanese

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Political Situation – Russia

1. Russian (land and air) war machine very powerful

2. Millions of men can be involved in PTO

3. Stalin’s intentions are clear – take what he can by force

4. Russian invasion of Japanese held territory in Far East is good (for US) short term but a real problem (for US) long term

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Potsdam Conference:July, 1945

Potsdam Conference:July, 1945

FDR dead, Churchill voted out of office as Prime Minister during conference.

Stalin only original. The United States

has the A-bomb. Germany to be divided

into occupation zones Japan must surrender

unconditionally P.M. Clement President Joseph Atlee Truman Stalin

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July 1945 TestTrinity Site, White Sands, NM Culmination of hundreds of

thousands of man-years work Some debate as to what might

happen Air burst (tower) Plutonium bomb successful Yield exceeded expectations

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Alternatives

1. Negotiated Peace Unacceptable to Allies Violates Potsdam Impossible to sell to Allied home fronts Does not really solve the problem Does not completely disarm military Does not occupy Japan (considered a

requirement to change culture)

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Alternatives

2. Blockade, Bomb and Wait Preferred USN option Few real targets left Kamikazes still a threat Could drag on for years Does not stop Russian advance; divided

Japan possible No guarantees

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Alternatives3. Homeland Invasion

Preferred USArmy option (MacArthur) Operation Downfall

Operation Olympic: X-Day 1-Nov-1945 Operation Coronet: Y-Day 1-Mar-1946

Massive logistical effort 42 carriers, 24 battleships, 400 destroyers, …, 39 divisions Olympic would be approx the size of Overlord Coronet would be twice the size of Overlord

12 to 18 month effort Does not stop Russian advance; divided Japan likely Japanese military likely to fight to the death Japanese civilians likely to fight to the death Causality estimates very high

Allies: 1 million+ dead Japanese: 5 - 10 million+ dead Japan planned to launch thousands of kamikazes at US troop ships and

estimated that they would kill 30% to 50% of the invasion force before they reached the shore

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Operation DownFall

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Alternatives

Ultimately decision is up to Truman Key dilemma for Truman is how to explain

any additional Allied deaths when he has the power to end the war with no more loss of Allied blood.

US (and Allied) hatred of Japs made the decision easier

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Final Phase

Tinian selected for staging and B29 base Little Boy (uranium) components shipped to

Tinian on USS Indianapolis (sunk by Jap sub 4 days after delivery)

Fat Boy (plutonium) components (2 bombs) shipped on modified B29s (509th Composite Group)

Secy of War Stimson ruled out Kyoto as a target (for a-bomb or conventional bombing) and made final targeting decisions

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Tinian Island, 1945Tinian Island, 1945

Little Boy Fat ManLittle Boy Fat Man

Enola Gay Crew

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Col. Paul TibbetsCol. Paul Tibbets

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The Beginning of theAtomic Age

The Beginning of theAtomic Age

0815 hours(local time)

6 – Aug - 1945

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Hiroshima – August 6, 1945

Hiroshima – August 6, 1945 B29, Enola Gay

70,000 killed immediately.

48,000 buildings.

destroyed. 100,000s died of

radiation poisoning & cancer later.

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Nagasaki – August 9, 1945

Nagasaki – August 9, 1945

B29, Boch’s Car 40,000 killed

immediately. 60,000 injured. 100,000s died of

radiation poisoning& cancer later.

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Japanese A-Bomb SurvivorsJapanese A-Bomb Survivors

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Immediate Effects

110,000 killed (both bombs)

100,000+ injuries

Truman warned of a rain of death (a bluff?)

Japanese were shocked but were the ruling military sufficiently shocked?

Emperor intervened

Last ditch effort by ruling military to thwart Emperor’s plan failed

Japan surrendered within a week (endured the unendurable)

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Immediate Effects

3 Russian Army groups composed of most experienced European conflict veterans attacked across the Manchurian border on 8-Aug-1945

Russians are highly mechanized and quickly enveloped much of the Japanese Kwantung Army

Japan provisionally accepted Potsdam ultimatum on 10 Aug 1945 with one proviso: emperor stays

Russian army continued to advance until 24 Aug 1945

In two weeks, the Russian army took thousands of square miles of Manchuria, China and Korea and 750,000 prisoners

Russia subsequently turned over most of the captured Japanese war material to the Chinese Communists and stripped Manchuria of its industrial plant as war reparations.

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Current Views

Controversy continues Should-Not-Have-Dropped-The-Bomb side argues:

Japan was worn out

Traditional bombing and blockade were working

Russia had invaded Manchuria so Japan would be fighting on multiple fronts

Japan was testing the negotiated peace prospects through Russian (initially) and later Swedish contacts

Invasion of Japanese homeland would cause “modest” Allied casualties

Was unconscionable to kill so many civilians

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Current Views Dropping-The-Bomb-Was-Right side argues:

Japan only appeared to be worn out; US home front was tired of war

Traditional bombing and blockade were clearly not working

Russian invasion of Manchuria could easily have led to a divided Japan

Japan was testing the negotiated peace prospects but efforts would have led to nothing (unconditional surrender was unacceptable)

Invasion of Japanese homeland would cause “substantial” Allied casualties (see “Hell To Pay”)

Invasion would have added at least 18 months to the war

In the grand scheme of things, very few people were killed (less than 0.2% of total deaths in WWII and far fewer than the Japanese massacred at Nanking)

An invasion would have likely killed at least 10 million Japanese (100X total death toll at Hiroshima & Nagasaki)

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In Closing Manhattan Project started 3 years after Einstein’s letter

Project took 3 years, involved 130,000 people across 30 sites

Project spent $3 billion; 90% on materials

Not until late summer July 1944 was bomb success moved from doubtful to probable

B29 Program was even longer and more expensive

~110,000 people died in two A-bombs

~183,000 died in two firebomb raids on Tokyo

Russian land grab in Aug 1945 was a significant help to Communist Chinese

MacArthur wanted to lead largest amphibious invasion in history; interesting to speculate on what would have happened had this occurred … who would have been the 1948 Republican Presidential candidate? 1952?

500,000 Purple Heart medals were manufactured during the summer of 1945 in anticipation of Operation Olympic. 60 years later there are still 100,000 left