Now that Niels Bohr’s famous unsent letter to Werner Heisenberg has finally been published—and for the most part only confirmed commentators in the differing views they already held—I have been looking back over the entire debate that my play Copenhagen seems to have provoked since it was first produced in New York in the spring of 2000, trying to work out what I still wanted to defend in my version and whether there was anything I needed to modify.
The reaction in New York, both positive and negative, took me by surprise. When I wrote the play I thought it unlikely that anyone would want to produce it. Even if I sometimes hoped I might find some small theater somewhere that would take it on, I can’t remember ever thinking that anyone would come to see it, much less have strong views about it. The successful run at the National Theatre in London, unexpected and gratifying as it was, passed peacefully. I got quite a lot of friendly suggestions and criticisms, mostly to do with my shaky science, and I made a number of modifications to accommodate them. I also came across a lot of material that was new to me—most particularly the US edition of the Farm Hall papers, with its critical commentary by Jeremy Bernstein, which made it clear to me that Heisenberg’s command of both the physics and the mathematics of fast fission was much less secure than I had supposed—and I rewrote the postscript to the published edition of the play to take account of this.
The New York production, however, opened up a much broader and more fundamental debate. A number of commentators expressed profound misgivings about the whole enterprise. Paul Lawrence Rose, the author of Heisenberg and the Nazi Atomic Bomb Project: A Study in German Culture, the most outspoken critic of both Heisenberg and my play, even managed to detect in it a “subtle revisionism… more destructive than [David] Irving’s self-evidently ridiculous assertions—more destructive of the integrity of art, of science, and of history.”
One of the most frequent complaints was that I should have laid more stress on the evils of the Nazi regime, and in particular upon the Holocaust; it was pointed out that Werner Heisenberg’s visit to Niels Bohr in Copenhagen in 1941 (the subject of the play) coincided with the Wannsee Conference. It was argued that I should have put Heisenberg’s visit to Copenhagen in the context of a number of subsequent trips he made during the course of the war to other occupied countries. It was also felt that I should have laid more stress than I did on Heisenberg’s stated view that Germany’s conquests, at any rate in Eastern Europe, were justified, and that its victory over Russia was to be welcomed.
With hindsight I think I accept some of these criticisms. I should perhaps have had Heisenberg justify Germany’s war aims on …