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WW 2 History Club

WW 2 History Club. The Bomb. 24 - Aug - 2011. Topics. Technology and Creation Competitive Development Elsewhere Military Situation in 1945 Political Situation in 1945 Alternatives July,1945 (Potsdam, the test, final prep) August,1945 (bombs dropped, Japan surrenders) Immediate Effects

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WW 2 History Club

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  1. WW 2 History Club The Bomb 24 - Aug - 2011

  2. Topics • Technology and Creation • Competitive Development Elsewhere • Military Situation in 1945 • Political Situation in 1945 • Alternatives • July,1945 (Potsdam, the test, final prep) • August,1945 (bombs dropped, Japan surrenders) • Immediate Effects • Current Views

  3. Technology & Creation • Einstein’s early theories suggest incredible power release (E=mc2 ) • Szilard: chain reaction, large bomb (tons of fissionable material required) • Einstein/Szilard letter to FDR • Briggs Committee (US): slow and ponderous; not focused on weapons • Frisch–Peierls Memorandum: small bomb (just lbs of fissionable material) feasible • MAUD Committee (UK): urgent -- UK at war; focused on weapons • NDRC  collaboration with UK • 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 • 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.

  4. The Manhattan Project:Los Alamos, NM I am become death, the shatterer of worlds! Major GeneralLesley R. Groves Dr. Robert Oppenheimer

  5. Manhattan Project Numbers • 3 years duration • 30 sites (Oak Ridge, Hanford and Los Alamos are best known) • 130,000 people • $2 billion (~ $25 billion today) • 90% to produce fissionable materails • 10% on the actual weapons • 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)

  6. Competitive Development • 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

  7. Competitive Development • 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

  8. Competitive Development • 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.

  9. Military Situation – Summer 1945 • War in Europe is over; Allies can now focus on Japan, but … • War in Pacific gets more deadly every day; Okinawa was a blood bath • Advantages of US island hoping strategy decay as we near Japan • US kill ratio declining • Japanese Navy virtually eliminated, but Kamikazes still a real threat • Japanese army is still large, powerful and determined

  10. Political Situation – Summer 1945 • US tired of war; running out of draftees • Russia flexing its muscles • Most major Japanese cities destroyed • Most major Japanese industries destroyed • But Japanese “will to resist” unchanged • Japanese military in control • Defeat is unacceptable to Japanese

  11. Political Situation – Russia • Russian (land and air) war machine very powerful • Millions of men can be involved in PTO • Stalin’s intentions are clear – take what he can by force • Russian invasion of Japanese held territory in Far East is good (for US) short term but a real problem (for US) long term

  12. 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

  13. July 1945 Test Trinity 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

  14. Alternatives • 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)

  15. Alternatives • 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

  16. Alternatives • 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

  17. Operation DownFall

  18. 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

  19. 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

  20. Tinian Island, 1945 Little Boy Fat Man Enola Gay Crew

  21. Col. Paul Tibbets

  22. The Beginning of theAtomic Age 0815 hours (local time) 6 – Aug - 1945

  23. Hiroshima–August 6, 1945 • B29, Enola Gay • 70,000 killed immediately. • 48,000 buildings. destroyed. • 100,000s died of radiation poisoning & cancer later.

  24. Nagasaki – August 9, 1945 • B29, Boch’s Car • 40,000 killed immediately. • 60,000 injured. • 100,000s died ofradiation poisoning& cancer later.

  25. Japanese A-Bomb Survivors

  26. 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)

  27. 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.

  28. 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

  29. 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)

  30. 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

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