" I may have replied "I know that this is possible in principle, but a terrific technical effort might be necessary, which one can hope, will not be realized anymore in this war." Bohr was apparently so shocked by this answer that he assumed I was trying to tell him Germany had made great progress towards manufacturing atomic weapons. In my subsequent attempt to correct this false impression I must not have wholly succeeded in winning Bohr's trust, especially because I only dared to speak in very cautious allusions ( which definitely was a mistake on my part) out of fear that later on a particular choice of words could be held against me. I then asked Bohr once more whether, in view of the obvious moral concerns, it might be possible to get all physicists to agree not to attempt work on atomic bombs, since they could only be produced with a huge technical effort anyhow. But Bohr thought it would be hopeless to exert influence on the actions in the individual countries, and that it was, so to speak, the natural course in this world that the physicists were working in their countries on the production of weapons. For an explanation of this answer one has to include the following complication which, although it was not talked about as far as I can remember, but of which I was conscious, and which may also have been on Bohr's mind, consciously or unconsciously. The prospect of producing atomic bombs while at war was at the time immeasurably greater on the American side than on the German, due to the whole prior history. Since 1933 Germany had lost a number of excellent German physicists through emigration, the laboratories at universities were ancient and poor due to neglect by the government, the gifted young people often were pushed into other professions. In the United States, however, many university institutes since 1932 had been given completely new and modern equipment, and been switched over to nuclear physics. Larger and smaller cyclotrons had been started up in various places, many capable physicists had immigrated and the interest in nuclear physics even on the part of the public was very great. Our proposition that the physicists on both sides should not advance the production of atomic bombs, was thus indirectly, if one wants to exaggerate the point, a proposition in favor of Hitler. The instinctive human position "As a decent human being one cannot make atomic weapons" thus coincided with an advantage for Germany. How far this was influencing Bohr, I cannot know of course. Everything I am writing here is in a sense an after the fact analysis of a very complicated psychological situation, where it is unlikely that every point can be accurate. - I myself was very unhappy over this conversation. The talk was then resumed a few weeks or months later by Jensen, but was equally unsuccessful. Even now, as I am writing this conversation down, I have no good feeling, since the wording of the various statements can certainly not be accurate anymore, and it would require all the fine nuances to accurately recount the actual content of the conversation in its psychological shading.

　　The second question in your letter concerned the alleged plans for my abduction from G?ttingen in the year 1947. This event can in retrospect only be viewed in a humorous vein, of course. It caused a lot of grief for the Britons who had to care for us and guard us, and they even had to relocate us, that is Hahn and me, for a period of some time from G?ttingen. Like clockwork there appeared in the middle of the night in front of my G?ttingen house two masked figures who had been promised a high reward if they were delivering me to an agent. These two men turned out after their capture to have been two Hamburg harbor workers who wanted to come into some good money on the cheap. In fact, however, the man who had engaged the harbor workers was identical to the one who had informed the British of the whole caper; he was a fraud who wanted to line himself up for a good position in the Secret Service. Only a year later the whole sham blew up and it has given us much to laugh about, naturally.

　　What you write about Weizs?cker, I can agree on. Only, there is a great deal of difference between this "Understanding for National Socialism in its beginnings" and the terminology "Loyalty towards Hitler" that you have used in your book. Why, one could in the first years very clearly combine a certain "Understanding for National Socialism" with the loathing of the person of its leader, Hitler, by, let's say, being desolate that "A genuine, idealistic desire of the German people was abused by a figure as unsavory as Hitler". The overlap "Hitler equals National Socialism", while proven through the subsequent years, was not yet clear to many Germans in the early beginnings.

　　Should you revise the passage about my conversation with Bohr in your book, I would be obliged, if I could see the text before publication and make corrections, if necessary.

　　With many warm greetings,

　　Yours

　　Werner Heisenberg

　　海森堡