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:: Nuclear Weapons History Pre Cold War Hiroshima and Nagasaki Chronology

Chronology of Part Played by Scientists in the decision to use the Bomb against Japan

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May 29,1957

1. Early 1944 -- "Everyone took for granted that the new bombs would be used in Europe if they were ready in time." (Compton, p. 231; for complete references see attached bibliography)

2. Early 1944 -- The men on the metallurgical project beginning to think about the future of atomic energy. (Compton, p. 231)

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3. Early 1944 -- H.D. Smyth presented A.H Compton with an outline of major questions relating to future of atomic energy. (Compton, p. 232)

4. Summer, 1944 -- At request of Metallurgical Project Council the Jeffries Committee was appointed by Compton to study "postwar work on nucleonics." (Compton, p. 232)

5. Autumn, 1944 -- The Tolman Committee was appointed by Gen Groves to look into future possibilities of atomic energy. Formed background for much of work of Interim Committee in spring of 1945. (Compton, p. 232)

6. Nov. 18, 1944 -- Jeffries Report, "Nucleonics Prospectus,"was submitted to Compton with a covering letter (unpublished) signed by Enrico Fermi, chairman, R.S. Mulliken, secretary, R.S. Stone, and C.A. Thomas.

7. Dec. 28, 1944 -- Tolman Committee handed its report to Gen.Groves on future of atomic energy (Compton, p. 233)

8. Early 1945 -- Conversations between Groves and A.H. Compton on use of bomb. Groves brings to Stimson's attention the concern of scientists about immediate use and long-term planning. (Compton,p. 233)

9. March, 1945 -- Szilard prepares memo. for Roosevelt (Szilard "memo")

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10. April 1945 -- Compton appointed a committee of those best informed to consider "anticipated human military and political consequences" of use of the bomb. Report of this committee was brought directly to Stimson (Compton and Daniels).

11. Spring 1945 -- Franck Committee at work. Referred to by Compton as "Within our project, the subcommittee on social and political consequences headed by James Franck focused its attention on this problem the use of bombs." (Compton, p. 233)

12. Spring 1945 -- Szilard write to the President and went to Washington to urge that the bomb not be used. (Compton, p. 241)

13. April 12, 1945 -- Stimson tells Truman briefly about new explosive after Truman is sworn into office. (Truman, p. 10)

14. April 13, 1945--Byrnes gives Truman more details; "later" Truman received a scientific account from Bush. (Truman, p. 10)

15. April 25, 1945 -- Stimson discusses with Truman the relation of the bomb to foreign policy and presents a memorandum discussing secrecy and international control. (Truman, pp. 85 and 87; Stimson & BundyIIp. 635ff)

16. April 1945 -- Appointment of Interim Committee by Truman "for recommending action to the executive and legislative branches." (Stimson "Decision" 

17. May 28, 1945 -- Szilard presents his March memo (which had not reached Roosevelt before his death) to James Byrnes in a personal interview in Spartenburg. (Szilard, "Memo")

18. May 31, 1945 -- Interim Committee discusses use of the bomb.1st meeting. Possibility of non-military demonstration brought up; Scientific panel asked to prepare a report on this. (Compton, pp. 219, 234)

19. June 1, 1945 -- Interim Committee after consultations with Scientific Panel unanimously decided: 1) bomb should be used against Japan as soon as possible) dual target, military and other buildings 3) should be used without prior warning. (Stimson, "Decision" ) 

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20. June 1, 1945 -- Conclusions of Int. Com. & Sc. Pan. brought to Truman by Stimson. (Truman, p. 419) Ralph Bard later changed his views and dissented from recommendation No. 3 of the June 1st report. (Stimson, "Decision,")

21. June, 1945 -- "Eventually, in June, 1945, the suggestions of these various subcommittees (of the Jeffries Committee) were collected into a combined report for the use of the Interim Committee and its successors." (Compton, p.232)

22. About June 9, 1945 -- Scientific panel to Interim Committee (Lawrence, Fermi, Oppenheimer, and A.H. Compton) to prepare report on possible non-military demonstration. (Compton, p. 240)

23. June. 1945 -- Hearing that Truman was consulting Stimson about use of the bomb, Franck " and certain members of his committee hastened to draft their conclusions." (Compton, p. 235)

24. June 11, 1945 -- Franck report presented to Stimson; drawn up by committee of 3 physicists, 3 chemists, and 1 biologist; "dispatched to Washington" six days before test explosion. (Editorial, Bull. At. Sc., May, 1946) ; Cf. Compton,p. 236 which states that Franck was in Washington, but Stimson was away and report was left for him with Geo. L. Harrison, his assistant)

25. June 11-16, 1945 -- Interim Committee and its scientific panel consider the Franck report (Stimson states, "The Interim Committee and the Scientific Panel also served as a channel through which suggestions from other scientists.were forwarded to me and to the President. Among the suggestions thus forwarded as one memorandum which questioned using the bomb at all against the enemy." Stimson, "Decision")

26. June 16, 1945 -- Scientific Panel reports to Interim Committee that they can propose no technical demonstration likely to end war and see no alternative to direct military use. (Stimson, "Decision,")

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27. 1945 -- Szilard circulates petitions in Chicago; urges others to do so in Oak Ridge and Los Alamos, requesting that the atomic bomb should not be used in World War II.(Compton, p. 241)

28. see below

Szilard petition in original form gets almost no support*. Szilard turns revised petition over to Compton for delivery to Washington, indicating that it was signed by 67 scientists residing in Chicago. (Compton, pp. 241-42) *Szilard says about 55 signatures.)

29. Counter-petitions to Szilard's circulated at Chicago and Oak Ridge. (Compton, pp.241-42)

30. July 2, 1945 -- Stimson sends memo to Truman discussing issue of strong warning to Japan of destruction if she does not surrender. Bomb not specifically mentioned 1) because of secrecy and 2) because not yet tested. (Stimson "Decision")

31. July 6, 1945 -- President's party, including Byrnes but not Stimson, leaves Washington for Potsdam. (This and some of the following items are included as relevant because of the question of what key officials were in Washington to receive the opinions of scientists that were expressed after this date).

32. July 12, 1945 -- Poll taken in Met Lab at Chicago.(Comption & Daniels)

33. July 15, 1945 -- Truman, Byrnes and others arrive in Berlin; greeted by Stimson at airport. (Truman, p. 339; on date of Stimson's arrival of.also #35).

34. July 16, 1945 -- Bomb successfully tested at Alamogordo.

35. July 16, 1945 -- News of test flashed to Truman at Potsdam by Stimson. (Truman, p. 415; of. Byrnes' statement, p. 262, that it took several days for decoding. Stimson & Bundy, II p. 637, says word of test was received at Potsdam on July 16th.)

36. July 17, 1945 -- Stimson flew to Potsdam and gave Truman full details of test Truman, p. 415)

36-a July 17, 1945 -- Revised Szilard petition--Szilard says about 63 signatures.

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37. July 17 to 24, 1945 -- Truman makes the decision to use the bomb against Japan when it is ready for delivery unless surrender has taken place. Truman does not date this decision exactly, but says as soon as he received details of test from Stimson on July 17th he called together chiefs of staff to review military strategy in light of successful test. (p. 415) Truman also says when he talked with Churchill he favored use of bomb (p. 419) Compton (p. 245) says that Truman later told him that it was at that meeting with the Joint Chiefs that he gave his"formal assent" to use the bomb.

38. July 17, 1945 -- As soon as Stimson arrived in Potsdam, (Truman here uses the date given in #36) Truman called in Byrnes, Leahy, Marshall, Gen. Arnold and Adm. King; they reviewed military strategy in light of the successful test. Truman, pp. 419-21)

39. July 23, 1945 -- Col. Nichols asks Compton at Oak Ridge for results of the poll at the Met. Lab. C. wrote out a message summarizing the results of the "votes and petitions" as objectively as he could. An hour later Nichols came back wanting to know what C. himself thought; gave opinion favoring use. (Compton, p. 246)

40. July 24, 1945 -- The War Department "was given orders" to instruct Gen. Spaatz that first bomb would be dropped as soon after August 3rd as weather permits. Truman told Stimson that order to Spaatz would stand unless Truman notified him of favorable Japanese reply. (Truman, p. 420-21)

41. July 24, 1945 -- Truman tells Stalin of "new weapon of unusual destructive force." (Truman, p. 416)

42. July 26, 1945 -- Allies broadcast demand that Japan surrender or face destruction.

43. July 28, 1945 -- Premier of Japan rejects Potsdam ultimatum as unworthy of notice. (Stimson, "Decision"; Truman, p. 421)

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44. Between decision to use the bomb and leaving Potsdam, Truman authorizes statement to be released after first bomb is dropped.(Truman, pp. 422-23)

45. August 2, 1945 -- Truman leaves Potsdam; flies to England; home by ship. (Truman, pp. 406, 421, ff.)

46. August 3, 1945 -- 1st day scheduled for dropping bomb, weather permitting. (Truman, p. 421.)

47. August 6, 1945 -- Hiroshima bombed (Aug. 5th at 7:15P.M., Washington time, Truman, p. 421)

48. August 8, 1945 -- Molotov informed Amb. Harriman in Moscow that Russia would consider itself at war with Japan as of Aug. 9th. Truman received this news on August 8th and immediately announced it at press conference. (Truman, p. 425)

49. August 9, 1945 -- Nagasaki bombed. ("We gave the Japanese three days in which to make up their minds to surrender, and the bombing would have been held off another two days had weather permitted." Truman, p. 426)

50. August 10, 1945 -- Japanese offer surrender on Potsdam terms but with reservation about sovereignty of emperor. (Stimson, "Decision")