Notes to Heisenberg.
As soon as I came to England and learned about the great American English preparations, I naturally had to
When I came to England in 1943 and was acquainted with the great American–English preparations, the question of how far Germany had come was naturally of the greatest importance both for physicists and for government authorities. I had the opportunity to discuss this question thoroughly both with the English intelligence service and with members of the English government, and I naturally reported all of our experiences including in particular the impression I got both during the visit to Copenhagen by you and Weizsäcker as well as during Jensen’s.
As the war approached its conclusion and Germany’s position became ever more difficult, the fear that it should succeed in producing atomic weapons naturally decreased, nor did their use in the war against Germany become an issue.
In that connection I have also been asked how your journey to Copenhagen was arranged and what authorization you had been given to speak to me about a question which was surrounded by such great secrecy and held such great political problems. (1)–(2)
As regards Jensen’s visit to Copenhagen in 1943, the war had already at that time taken a course quite different from what you and Weizsäcker expressed as your conviction in 1941. Jensen described the efforts to increase the production of heavy water in Norway and mentioned in this connection that, for him and other German physicists, it was only a matter of an industrial application of atomic energy. At that time, however, I had to be very cautious and sceptical, partly on the basis of rumours of new German weapons, partly because of my own difficult position due to the constant surveillance of the German police.
Of course, it is your account published in Jungk’s book which has created such keen public interest in all these wartime connections
When I, especially after the publication of Jungk’s book, about which I have been questioned not only by colleagues in many different countries, but especially as a consequence of the thorough investigations of archives, which one from
I recall that you said in that connection that you did not know what I thought but that you had worked so closely with it yourself that
(1) (Because of the great experience that I had in subsequent years through connection with counterespionage by the secret intelligence service, I fully understand the reason for such questions.) (2)