The conversations with German physicists in the autumn of 1942.
Through the German authorities Heisenberg and Weizsäcker had arranged a physics conference at the German Institute in Copenhagen, which had been established by the occupying power. Only a few Danes took [part] in this conference, and among them none of the leading physicists at the University’s Institute for Theoretical Physics. During those days, however, Heisenberg and Weizsäcker visited this Institute and had conversations with Chr. Møller as well as with Bohr.
During a conversation with Bohr, Heisenberg stated that he was working on the release of atomic energy and expressed his conviction that the war, if it did not end with a German victory, would be decided by such means. Heisenberg said explicitly that he did not wish to enter into technical details but that Bohr should understand that he knew what he was talking about as he had spent 2 years working exclusively on this question.
Bohr restrained himself from any comment but understood that this was important information which he was obliged to try to bring to the attention of the English.
During conversations with Møller, Heisenberg and Weizsäcker sought to explain that the attitude of the Danish people towards Germany, and that of the Danish physicists in particular, was unreasonable and indefensible since a German victory was already guaranteed and that any resistance
against cooperation could only bring disaster to Denmark. In a conversation with Møller, Weizsäcker further stated how fortunate it was that Heisenberg’s work would mean so much for the war since it would mean that, after the expected great victory, the Nazis would adopt a more understanding attitude towards German scientific efforts.