Serving the Reich

by Philip Ball

  11

  ‘Heisenberg was mostly silent’

  Having rounded up the German scientists, the Americans seemed unsure what to do with them. Reginald Victor Jones, a physicist in charge of intelligence for the British Air Staff, cannily offered to take them off the Americans’ hands. That is how the Uranium Club came to be flown to Cambridgeshire and incarcerated in an elegant country house called Farm Hall in the little town of Godmanchester. There were ten detainees: Heisenberg, Laue, Weizsäcker and Hahn, along with Paul Harteck, Erich Bagge, Kurt Diebner, Walther Gerlach, and the KWIP researchers Horst Korsching and Karl Wirtz, specialists on the separation of isotopes. (Wirtz was also in charge of reactor construction at the Berlin institute.) Hahn and Laue had had little involvement in the wartime nuclear research, and Laue was puzzled why he was being held. But the British had their reasons for wanting him there. They figured that the presence of these senior figures would provide a moderating influence on the others, and anticipated that their own scientists would appreciate the chance to speak to them. Moreover, the Allies were already contemplating the rebuilding of science in Germany, and had identified the relatively uncompromised Laue as an ideal figurehead.*1

  Farm Hall was bugged with microphones connected to recording equipment, so that British intelligence might monitor the German physicists’ conversations to gauge their morale and determine whether they could be trusted to cooperate in the post-war reconstruction. With characteristic overconfidence, the scientists didn’t imagine that their captors would have the wherewithal for such measures. ‘I don’t think they know the real Gestapo methods,’ said Heisenberg naïvely, ‘they’re a bit old fashioned in that respect.’ As a result, the Farm Hall recordings are all the more historically valuable for their candour.

  But this unique resource was locked away for decades after the war, first for security reasons and then because of bureaucratic complications, not to mention the objections of the surviving detainees. Samuel Goudsmit was permitted to include a few quotes from the transcripts in his 1947 book Alsos, but without revealing their source. The very existence of the recordings was not disclosed until the publication of Leslie Groves’ somewhat self-serving memoir Now It Can Be Told (1962), which included some further excerpts. The full story was not really told for another thirty years, however. The transcripts were finally made public in February 1992, and were published the following year as Operation Epsilon, the intelligence code name for the programme. Even this account was not exhaustive—perhaps only about 10 per cent of what was recorded on shellac disks at Farm Hall was actually transcribed into the British military reports, and the disks themselves were later reused. All the same, when he first gained access to the transcripts, historian of physics Jeremy Bernstein, one of the principal documenters of the incipient nuclear age, admitted to feeling like Jean-François Champollion finding the Rosetta Stone. Now one could at last hear what the German physicists had really thought.

  Private conversations

  One can see why these scientists had been happy for the Farm Hall recordings to stay buried. Their tendentious, artfully constructed ‘official’ story of the German nuclear programme is undermined by much of what they said in unguarded ignorance of the eavesdropping. That they bicker, fret, engage in recrimination and separate into factions is surely to be expected from men of a defeated nation, worried about their families and relatives and uncertain about their future. Much more damning is the lack of any serious moral reflection on their wartime activities, or indeed on the culpability of Germany in general. They are irritated and aggrieved at being held captive, as though the victims of some grave injustice. ‘Things can’t go on like this’, chafes Heisenberg; ‘It won’t do’, Harteck concurs. All the same, their predicament feeds a sense of importance: ‘These people have detained us firstly because they think we are dangerous; that we have really done a lot with uranium’, says Weizsäcker; ‘Secondly, there were important people [among the Allies] who spoke in our favour and they wanted to treat us well.’ As Major T. H. Rittner, the British officer in charge of Operation Epsilon, pointed out, they did not yet seem to have quite accepted that they had lost the war.

  Weizsäcker’s self-aggrandizing claim that the physicists were deemed ‘dangerous’ because of their uranium research was deflated by the news that they heard on the BBC radio broadcast on 6 August 1945:

  The first atomic bomb has been dropped by a United States aircraft on the Japanese city of Hiroshima. President Harry S. Truman, announcing the news from the cruiser, USS Augusta, in the mid-Atlantic, said the device was more than 2,000 times more powerful than the largest bomb used to date . . . The president said the atomic bomb heralded the ‘harnessing of the basic power of the universe’. It also marked a victory over the Germans in the race to be first to develop a weapon using atomic energy.

  This was the first inkling for the German scientists that they had not been ahead of the Allies after all, but had lagged behind pitifully. Goudsmit—who had kept this information from them during the Alsos mission—confessed later that he would have dearly liked to be in the room with them that day. Hahn, who had not been directly engaged in the uranium work and so had no reputation to defend, was merciless to his colleagues. ‘You’re just second-raters and you might as well pack up’, he said to an incredulous Heisenberg.

  At first Heisenberg simply did not believe it. ‘All I can suggest’, he insisted,

  is that some dilettante in America who knows very little about it has bluffed them in saying ‘If you drop this it has the equivalent of 20,000 tons of high explosive’ and in reality doesn’t work at all.

  Even then, it appears, the German scientists were desperate to convince themselves that they enjoyed some kind of technical superiority over their Allied rivals. They clung to the belief that this gave them a strong and perhaps lucrative bargaining position, able to influence how postwar nuclear technology would evolve among the superpowers. They imagined, for example, that even if the Americans had made a bomb, they might not have got as far as the Germans in devising a controlled-fission uranium machine—a reactor. If that’s so, said Heisenberg—and he convinced himself that it looked that way—‘then we are in luck: there is a possibility of making money’.

  Soon enough, however, they had to accept that the Allied atomic bomb was genuine. ‘I think it is dreadful of the Americans to have done it’, Weizsäcker attested. ‘I think it is madness on their part.’ To which Heisenberg responded, ‘One can’t say that. One could equally well say “That’s the quickest way of ending the war.”’ But Weizsäcker was already starting to insist on the story that he later developed with great rhetorical force. ‘I believe the reason we didn’t do it’, he declared to his colleagues on that day of the Hiroshima announcement, ‘was because all the physicists didn’t want to do it, on principle. If we had all wanted Germany to win the war we would have succeeded.’

  Hahn, to his credit, refused this easy evasion. ‘I don’t believe that’, he said, ‘but I’m thankful we didn’t succeed.’ Hahn was apparently so shaken by the news that the English guards asked Laue to make sure that he did not harm himself. Laue and Bagge kept a vigilant eye on the agitated professor late into the night, until they saw him drift off to sleep.

  Confronted with the reality of nuclear destruction, the German scientists had to ask themselves if this was really what they had been pursuing in Nazi Germany. How would it seem if they were deemed to have been trying to deliver such awesome power to Hitler? And so they began to devise their exoneration. The story, as described with irony by Laue on 7 August in a letter from Farm Hall to his son in America, ran as follows:

  Our entire uranium research was directed towards the creation of a uranium machine as a source of energy, first, because no one believed in the possibility of a bomb in the foreseeable future, and second, because no one of us wanted to lay such a weapon in the hands of Hitler.

  Laue himself never accepted this convenient fiction. In a letter to Paul Rosbaud in 195
9 he described its genesis in dismissive tones:

  After that day we talked much about the conditions of an atomic explosion. Heisenberg gave a lecture on the subject in one of the colloquia which we prisoners had arranged for ourselves. Later, during the table conversation, the version was developed that the German atomic physicists really had not wanted the atomic bomb, either because it was impossible to achieve it during the expected duration of the war or because they simply did not want to have it at all. The leader in these discussions was Weizsäcker. I did not hear the mention of any ethical point of view. Heisenberg was mostly silent.

  For his scepticism and general denigration of German militarism at Farm Hall, Laue told Rosbaud that he received a great deal of hostility and criticism from his fellow detainees, especially Weizsäcker and Gerlach.

  Gerlach, who had replaced Abraham Esau in charge of physics at the Reich Research Council in 1944, was devastated by the whole situation, behaving rather like a defeated general. Yet Rosbaud considered him much more than a Third Reich careerist and Nazi apologist. When Rosbaud had discussed the RRC appointment with him at the time, Gerlach had readily conceded that Germany had already lost the war, and insisted that ‘I don’t intend to make any war physics nor to help the Nazis in all their war efforts. I just want to help physics and our physicists.’ However, Rosbaud had taken exception to Gerlach’s insistence on making a distinction between his country and its leaders—a fantasy shared by many intellectuals, according to which they could fight for Germany and pretend they were not at the same time supporting Hitler. Gerlach’s position, according to Rosbaud, had been that ‘Germany must not lose the war, but she must get rid of the Nazis.’ It was a common view among the ‘good’ Germans: they wanted Germany to win the war, but Hitler to lose it. ‘He could not’, Rosbaud later wrote,

  and probably did not want to understand that Germany, the war and Hitler could not be regarded separately, and that the war only either could be won with Hitler or lost with Hitler. I would never classify Gerlach into this group of scientists which only wanted Germany to win the war for the continuation of their own personal comfort of life and of their work. His desire was absolutely honest, he loved his country and wished the best to her and did not want her to perish.

  At Farm Hall the bewildered Gerlach did not acquit himself well: dismayed that his guards did not treat him more deferentially, snapping at his colleagues, and worrying that when they returned to Germany the physicists would be held responsible for losing the war because they did not make an atomic bomb. Gerlach fretted that Niels Bohr might have helped the Americans make the bomb (in fact he did not), whereas he had vouched for the Danish physicist personally to the Nazis: it was as though he imagined they could somehow still punish him for this misjudgement. ‘I went to my downfall with open eyes’, he insisted, ‘but I thought I would try and save German physics and German physicists, and’—the self-delusion and the aggrandizement as intransigent as ever—‘in that I succeeded.’

  Myths of the bomb

  The Farm Hall Lesart, as Bernstein calls it (the German word means a particular reading of a historical text), became the ‘truth’ energetically promoted by Heisenberg and Weizsäcker. To the latter it was an assertion not just of innocence but of actual moral superiority. As Weizsäcker said at Farm Hall,

  History will record that the Americans and the English made a bomb, and that at the same time the Germans, under the Hitler regime, produced a workable engine. In other words, the peaceful development of the uranium engine was made in Germany under the Hitler regime, whereas the Americans and the English developed this ghastly weapon of war.

  This was the view expounded, at Weizsäcker’s urging and in emotive terms, by the Austrian writer Robert Jungk in his book on the Manhattan Project Brighter Than a Thousand Suns (1956):

  It seems paradoxical that the German nuclear physicists, living under a saber-rattling dictatorship, obeyed the voice of conscience and attempted to prevent the construction of atom bombs, while their professional colleagues in the democracies, who had no coercion to fear, with very few exceptions concentrated their whole energies on production of the new weapon.

  It is a pernicious myth. But myths, according to Mark Walker, were ‘what these scientists felt they needed most’. That was, of course, no more than what many people seemed to need after the war, and in many ways still do.

  Once this aspect of Jungk’s book began to draw criticism, Weizsäcker and Heisenberg sought to distance themselves. Weizsäcker claimed that Jungk had exaggerated in attributing to him the story of a ‘conspiracy’ among the scientists to deny Hitler the bomb. Jungk in turn said that he had been misled, even ‘betrayed’, by the scientists. One can see his point. Soon after the book was published, for example, and before its distorted narrative had drawn much fire, Heisenberg sent Jungk a letter in which he voiced no reservations about the way it depicted the Germans’ attitude to the bomb, but focused instead on burnishing the myth of how the scientists had ‘resisted’ the Nazis:

  I want to thank you very much for having your publisher send me a copy of your fine and interesting book about the atomic scientists . . . I find that, overall, you characterized the atmosphere among the atomic scientists very well . . . Overall, the German physicists acted in this dilemma as conservators of sort of that which was worthy and in need of conserving, and to wait out the end of the catastrophe if one was lucky enough to still be around.

  The legend that the Germans intentionally avoided making a bomb for Hitler also shaped journalist Thomas Powers’ 1993 book Heisenberg’s War. Powers argued that the German physicists, and Heisenberg in particular, had not just averted the construction of a bomb because of moral scruples but had actively sabotaged it. ‘Heisenberg did not simply withhold himself, stand aside, let the project die’, Powers wrote. ‘He killed it.’ Powers adduces some wartime intelligence reports that appear to support this contention. But if there is anything substantial in it, it is very hard to see why the German physicists, so keen to exculpate themselves, failed to make that case themselves in the aftermath of the war.

  Nonetheless, the ‘sabotage’ idea remains in currency with a few of Heisenberg’s defenders.*2 However tenuous Powers’ claims are, one must have some sympathy for him, since his case rests heavily on the apparent testament of none other than Heisenberg himself. In her 1986 book Biography of an Idea Ruth Nanda Anshen, Heisenberg’s American editor of his memoir Physics and Beyond, quotes a letter that she received from him in 1970 in response to some queries that arose from a review of Goudsmit’s book Alsos. Here Heisenberg writes that ‘Dr Hahn, Dr von Laue and I falsified the mathematics in order to avoid the development of the atom bomb by German scientists.’

  This extraordinary statement demands extraordinary evidence. Sadly, there seems to be none. Anshen says that the letter was among the correspondence that she gave to the Columbia University Library—but there is no sign of it in these documents today. Yet would Anshen, who admired Heisenberg, have simply made it up? Could she, aged eighty-six, be misremembering something? But then whence the full, direct quote in her book?

  If we believe Anshen’s account, we must then also believe that Heisenberg was prepared, if necessary, to lie outright about the German uranium work. There seems to be no alternative interpretation. The idea that the German scientists fixed the maths contradicts everything else that they, Heisenberg included, had ever said about their work towards a bomb. Neither Laue nor Hahn could be consulted about their alleged collusion in this plot, for (‘conveniently’, as Paul Lawrence Rose says) they were both dead by 1970. If Heisenberg was telling the truth to Anshen, he’d been spinning a lie for over two decades—and incomprehensibly so, for why would he have covered up for so long such a clear demonstration of his moral rectitude?

  The affair is truly perplexing. But despite Powers’ conclusions, it seems hard to see it as anything other than extremely damaging for Heisenberg. Rose believes that, when he wrote to Anshen, Heisenberg may hav
e been troubled by the fear that his mistaken calculation about the critical mass of a bomb in 1940 was about to come to light—in which case his claim would transform an embarrassing scientific blunder into an act of heroism. In any event, Powers’ version of the story is rejected by historians; his book was dismissed in the Bulletin of the Atomic Scientists as a fiction, while the suggestion that the Germans sabotaged the maths to deny Hitler the bomb is, in Mark Walker’s view, ‘tragically absurd’.

  Copenhagen

  Much of the debate about Heisenberg’s wartime record hinges on the fact that, unlike Debye, he had much to say subsequently about his motives and goals while working under Hitler. As the war progressed, Heisenberg became one of the National Socialists’ most valued ambassadors of German culture. Yet he argued later that he and his colleagues had merely bided their time under oppression, trying ‘to keep order in those small corners to which our own lives [were] confined’. He recast the German physicists’ meek and passive collaboration as a form of active opposition, and claimed that he had stayed in Germany purely because he wanted to help ‘uncontaminated science make a comeback after the war’.

  It was on a ‘cultural’ mission with Weizsäcker to Nazi-occupied Denmark in 1941 that Heisenberg had the meeting with Niels Bohr now made famous by Michael Frayn’s play Copenhagen. Frayn examines the several conflicting accounts of that event, implying that we can hardly expect to arrive at absolute historical truths when we cannot even be sure of our own motivations. The historical accuracy of the play has been debated passionately—Paul Lawrence Rose lambasts it as a work of revisionism more damaging than historian David Irving’s crude Holocaust denial, while Klaus Hentschel asserts that the play deserves to be admired for a ‘courageous polyphony’ that historians too rarely admit. But Frayn was surely right to refuse any definitive reading of the event.