Foreign Relations of the United States: Diplomatic Papers, The Conference of Berlin (The Potsdam Conference), 1945, Volume II

S/AE Files

No. 1306
Prime Minister Churchill to the Secretary of War (Stimson)

top secret
and personal

Mr. Secretary Stimson[:] I enclose a photostat record of the Hyde Park Agreement on T. A., for which you asked the Chancellor of the Exchequer.¹

This photograph was taken by a special photographic section of the Air Ministry, and flown out here in the charge of a trusted officer.

W[inston] S C[hurchill]

Berlin, 18.7.45.

[Enclosure]

top secret

Tube Alloys²

Aide-Mémoire of Conversation Between the President and the Prime Minister at Hyde Park, September 18, 1944³

1. The suggestion that the world should be informed regarding Tube Alloys, with a view to an international agreement regarding its control and use, is not accepted. The matter should continue to be regarded as of the utmost secrecy; but when a “bomb” is finally available, it might perhaps, after mature consideration, be used against the Japanese, who should be warned that this bombardment will be repeated until they surrender.

2. Full collaboration between the United States and the British Government in developing Tube Alloys for military and commercial purposes should continue after the defeat of Japan unless and until terminated by joint agreement.

. . . . . . . . . . . . . .

• F[ranklin] D R[oosevelt]
• W[inston] S C[hurchill]

1. Sir John Anderson. Following the death of President Roosevelt, an authenticated text of the enclosed aide-mémoire was not available to responsible American officials. Before the Berlin Conference, Stimson had asked the British Government to supply a photocopy of the aide-mémoire.
2. The following manuscript notation appears in the top margin: “A copy of this aide-mémoire was left with Pres. Roosevelt. Another copy was given to Adl. Leahy to hand to Lord Cherwell. J[ohn] M[iller] M[artin.]” The copy of the aide-mémoire in the Roosevelt Papers deposited in the Franklin D. Rooseveit Library at Hyde Park does not, of course, bear this notation nor that quoted in footnote 3, infra, but it does have a handwritten date, “18. 9”,i. e.,September 18, under Churchill’s initials.
3. At this point there is the following marginal manuscript notation: “actually 19th J[ohn] M[iller] M[artin.]”