Churchill's Bomb

by Graham Farmelo

  One section of the agreement made clear – almost embarrassingly so – that Britain was the junior partner and that, to be granted even that role, the Prime Minister was prepared to make what could well be a substantial concession:

  The Prime Minister expressly disclaims any interest in these industrial and commercial aspects beyond what may be considered by the President of the United States to be fair and just and in harmony with the economic welfare of the world.

  Churchill regarded British participation in the American-run project as the only way of ensuring that his scientists learned enough to build the weapon after the war. To achieve that goal, he gave the President an unprecedented veto on the development of nuclear power in Britain, a potentially profitable and strategically important industry.

  The two leaders had also given themselves a veto on the other’s use of the Bomb against any other country, relinquishing an element of their sovereignties. Had American lawmakers known of this decision, they would almost certainly have declined to support it, and it is possible that Churchill’s own government would have found such a veto hard to follow, too. In the long term, after one or both of the leaders had left office, it was hard to imagine that their successors would want to be bound by it. Lindemann appreciated this, to the irritation of Churchill, who always insisted that the agreement was the best possible one that Britain could have obtained in the circumstances.25 Had he been quicker off the mark and more shrewdly advised two years earlier, when Roosevelt first offered to develop the Bomb jointly, Britain would have been well placed to negotiate a considerably better deal.

  Churchill was delighted with the Quebec Agreement: it had for the first time committed Roosevelt – in writing – to a policy of collaboration, and immediately achieved its aim of involving British physicists in the Manhattan Project. Within a few hours of the document’s signature, Rudi Peierls, Francis Simon and Mark Oliphant arrived in the US to recommence collaboration, Chadwick following soon afterwards.26 These were the first of some two dozen British scientists to play a part in building the Bomb.

  One serious weakness of the document was the vagueness of its wording – Anderson predictably had delivered a compromise but had not demanded the specificity needed to make the agreement watertight. As a result, the question of what kind of information was to be shared was unclear and there were several elastic loopholes in the text, ready to be exploited by Groves and his colleagues if they so wished.

  The agreement did not explicitly mention the Soviets for a reason that was too obvious to put in writing: the two leaders wanted the Bomb kept secret from them. Churchill was finding it hard to deal with Stalin, who was becoming increasingly importunate. On the final day of the Quebec Conference, after an angry telegram arrived from the Soviet leader about the Allies’ response to Italy’s surrender, Churchill commented darkly that ‘Stalin is an unnatural man’, and worried that ‘grave troubles’ were ahead.27 Yet Churchill knew that Britain and the United States had to deal with what was sure to be ‘the greatest land power in the world after this war’ and wanted to be on ‘good terms’ with Russia after the conflict.28 After an official visit to Canada, on the sleeper train to Boston, Churchill dictated a speech he was to give the next day, Monday 6 September, at Harvard University about how to strengthen the bonds between the English-speaking peoples. He gave the speech, broadcast on both sides of the Atlantic, at a ceremony at which he was to be presented with an honorary degree by James Conant, who had worked hard for many months to marginalise Britain’s involvement in the American project to build the Bomb.

  After Churchill was presented with a red morocco tablet bearing the degree, he advanced to the lectern looking like Holbein’s Henry VIII, dressed in an Oxford gown.29 With loud applause echoing around the hall, Churchill put on his glasses, walked to the lectern and began his speech with a confidence that befitted the boldness of this theme – the need for a permanent alliance between Britain, its Empire and America. He stressed the countries’ common values and the ‘gift of a common tongue . . . a priceless inheritance’ before floating the idea that one day the countries might share ‘common citizenship’. In the climax of the speech, he looked forward to the war’s endgame, perhaps also thinking of the sacrifices of sovereignty he believed that he and Roosevelt had made in signing the secret Quebec Agreement:30

  I am here to tell you that, whatever form our system of world security may take, however the nations are grouped and arranged, whatever derogations are made from national sovereignty for the sake of the large synthesis, nothing will work soundly or for long without the united effort of the British and American peoples.

  The audience rose as one to applaud and cheer, leaving him as the only person in the theatre sitting down.

  After what had been his longest visit to North America during the war, Churchill arrived back in London on 19 September. Lindemann was far from happy with the Quebec Agreement. As he wrote to Churchill a few weeks later, he thought it entailed ‘not an altogether satisfactory version of cooperation’, adding tactfully, ‘It seems likely to be the best we can get for the time being.’31 In the following months, as the agreement’s flaws became plain, Lindemann was to take an even less rosy view of it. The matter became a bone of contention between him and the Prime Minister, who regarded it as the granitic foundation stone of Anglo-American nuclear politics.

  Although both Churchill and Roosevelt now understood that nuclear weapons would be an important asset after the war, they do not appear to have thought through the implications of developing them. Nor did they or their advisers seem to have reflected on the consequences of excluding Stalin, who was chafing at the disproportionate price his country was paying to win the war and already looking forward to a territorial pay-off when it was over. Churchill’s apparently weak grasp of the effects the new weapons were likely to have on geopolitics contrasts sharply with the far-sightedness he had demonstrated in ‘Fifty Years Hence’ more than a decade before. In that essay, he had worried that democratic governments would shy away from taking a principled view of their new military capabilities and, instead, muddle along from one compromise to the next. Now, in one of the awkward concessions inevitable during the hurly-burly of war, he had made a narrow and woolly agreement with his closest ally to develop one of the new technologies he had once dreaded, and to keep it secret from their governments. Neither Churchill nor Roosevelt nor any of their close associates appears to have thought deeply about what would happen when other countries acquired the Bomb after the war.

  This complacency would soon be challenged. Seven weeks after Churchill and Roosevelt signed the Quebec Agreement, a refugee arrived in London and encouraged fresh and provocative political thinking about the implications of nuclear weapons. The interloper, who knew nothing about plans to build the Bomb, was not even a politician, but a physicist.

  SEPTEMBER 1943 TO MAY 1944

  Bohr takes a political initiative

  ‘Bohr was like a great big cuddly teddy bear, and was always inside a cloud of smoke.’

  Chadwick’s daughter JOANNA, November 20121

  The prospect of Niels Bohr’s arrival in London excited the normally imperturbable Sir John Anderson so much that it turned the ink in his pen from black to purple. Bohr was worthy, Anderson told his colleagues, ‘to rank in every respect with a Newton or a Rutherford’.2 If not at their level of achievement, Bohr was famous as both a scientist and a sage, so he seemed certain to be a great asset to Tube Alloys. He would probably give the British government some much-needed influence on the Manhattan Project, too. Before long, he was pressing for access to the Prime Minister, determined to alert him to the threat that nuclear weapons might pose unless Anglo-American thinking about them changed. It was not clear, however, that Churchill would be prepared to listen to him.

  The story of Bohr’s escape from Denmark would have sounded far-fetched in a John Buchan thriller.3 Sitting out the war at his Institute in Copenhagen, under the relatively benign rule of the lo
cal Nazi satraps, he had been able to work almost normally. In mid-September 1943, the mood in the city darkened: anti-German feelings were hardening and rumours began to spread that the Nazis were planning to deport local Jews – as Bohr’s mother had been Jewish, he would be affected. On 29 September, after hearing a tip-off that Jews in the city were about to be arrested, he and his wife – carrying a few belongings – sneaked out of their home early in the evening, hid in a cottage near the coast and, with a few other escapees, travelled by boat under the moonlight to Limhamn in neutral Sweden, somehow avoiding the roving German patrol vessels. There, Bohr and his wife crawled across the beach on their hands and knees to safety. His four sons followed a few days later. By then, although he was talking about the plight of Danish Jews with the Swedish King and Foreign Minister, he believed he would be more useful in Britain, which he thought of as his second home. When Lindemann renewed an earlier invitation to fly him to London,4 Bohr left his family in the care of the Swedish authorities and boarded an unarmed Mosquito bomber, where he was strapped into the unpressurised bomb bay, as the plane had no seats for passengers. For the first time in his life, Bohr’s huge head presented a problem and made the journey unpleasant – the helmet he had been given was fitted with earphones, but it was much too small for him. As a result, he did not hear the captain’s instructions to wear an oxygen mask and so spent most of the flight unconscious with altitude sickness.

  After landing in Scotland on 6 October, he was whisked onto a flight south and was met at Croydon Airport by his old friends James and Aileen Chadwick, before being supplied with a set of official papers.5 Bohr arrived knowing nothing about Tube Alloys and the Manhattan Project. He had guessed two years before, however, that a nuclear weapon might be about to become a reality after he received a secret invitation from Chadwick to work in Britain (Danish resistance fighters produced a typescript of the message from a microdot in the end of a door key slipped to them by the British security services). Chadwick escorted his guest to London and checked him into the Savoy Hotel, where they were joined for dinner that evening by Sir John Anderson. It was during these conversations that Bohr heard about the Allies’ work on the Bomb. He was astonished to hear that the project he had once confidently dismissed as being too enormous to contemplate was now in full swing.

  The Whitehall mandarins quickly appointed the man they called ‘the Great Dane’ as a special consultant to Tube Alloys.6 It was obvious that he was no ordinary scientist – true, he had all the unworldliness expected of an accomplished intellectual, but he was also surprisingly down to earth. Now approaching his fifty-eighth birthday, his thin hair was greying but he still ran up flights of stairs two steps at a time, displaying the last remnants of the athleticism he had shown as a soccer player in his youth, when he was an effective goalkeeper.7

  His personality was a unique mix of companionability, wisdom and an endearing incoherence. Though a generous spirit, he was a poor listener. After a long and tortuous exchange of views – mainly with himself – his face would light up with a sunburst of a smile as he returned to terra firma and cadged another match for his pipe, which somehow always seemed to need rekindling. Bohr was a man of words but he had two serious problems with them – as he put it, he was determined not ‘to speak more clearly than I think’, and ‘If I cannot exaggerate, I cannot talk.’8

  He had no idea how to manage his affairs, as Wallace Akers’s secretary quickly realised. Once, before he left for an important meeting, she packed him off with six typed copies of travel instructions, telling him: ‘If you put one of these into each of your pockets, you are sure to find one when you need it.’9 Help arrived a week later when his undergraduate son Aage – later a Nobel Prize-winning nuclear physicist himself – joined Niels and served as his minder, secretary and amanuensis. The two men soon felt at home, despite the sandbags, the rolls of barbed wire on the streets and the air-raid warnings, whose tiresome wailing they had not had to endure in occupied Denmark.10 Anderson arranged for them to be issued with ration books and gave them an office in the Tube Alloys headquarters in Old Queen Street and an apartment nearby in St James’s Court.

  Bohr talked about the weapon at length with British physicists, but what interested him most were its political implications, especially in the long term. During hours of discussions with Lindemann and Anderson, his thoughts on the nuclear project coalesced into a way of looking at the Bomb that took his colleagues by surprise.

  Bohr believed that if the Bomb could be made, it was foolish to pretend that the underlying science and technology could be kept secret: sooner or later – more likely, sooner – the government of any industrially advanced country could instruct its scientists to find out how it was done and then direct them to manufacture the weapon. A terrible arms race was therefore inevitable, with leading countries trying to outdo each other by building ever more powerful weapons, and the world would have to endure one nuclear conflict after another. It would be better, Bohr believed, for the Allies – including the Soviet Union – to share the idea and thus begin a new era of harmony and trust. This vision was long on idealism and short on detail, with no plan for beginning these negotiations, nothing about dealing with terrorists who might get hold of the weapon, and no indication of how acquiring it would affect conventional warfare. Yet Anderson – and even, it seems, Lindemann – saw the beginnings here of a new way of thinking about the latest military technology, and they decided it was worth trying to talk to the Prime Minister.

  Bohr arrived in London eager to contribute to the war effort, having spent so long out of touch with most of his friends in the community of British scientists. The government in London wanted to keep his activities secret, but the New York Times blew the whistle on him three days after his arrival. It then compounded the embarrassment with a garbled report that he had brought to London plans for a new invention ‘of the greatest importance for the Allied war effort’ involving ‘atomic explosions’.11

  Morale was low in the Tube Alloys head office. After Churchill and Roosevelt had signed the Quebec Agreement, the normally effervescent Wallace Akers had been ‘feeling a bit depressed’12 and alarmed that progress was so slow. The resumption of cooperation was, he knew, ‘very much at the discretion of the Americans’, and signs were not encouraging.13 He probably felt no better when, under pressure from Churchill, he was obliged to stand down from his role in the US after Bush and Groves objected that he was irredeemably tainted by his connections to ICI.14 Akers’s place was taken reluctantly by the Americans’ favourite British nuclear scientist, James Chadwick.

  There had been a surge of optimism in the office after the Quebec Agreement was signed, though it was fading now that the British scientists were finding it hard to work closely with their American counterparts. Groves talked with Chadwick, Oliphant and their colleagues with disarming frankness, but it was plain that the General wanted to involve only the few British scientists who could be useful to him. He had no intention of sharing information on the Manhattan Project with the British as openly as Churchill had expected.15 The loopholes in the agreement were starting to gape, and Groves had no compunction about slipping through every one of them.16

  Bohr brought encouraging news to his new Tube Alloys colleagues. Two years before, in August 1941, he had been visited in Copenhagen by his friend Werner Heisenberg, then working behind Nazi lines, who brought a sketch of a nuclear device that Bohr believed the Germans were working on. Bohr was unsure what the device was but now believed, according to the later recollections of Michael Perrin, deputy director of Tube Alloys, ‘that the Germans had concluded that the Bomb project was impracticable’.17 This chimed with the findings spelled out in intelligence reports, though it was still conceivable that Hitler’s scientists were working on the Bomb and had somehow managed to keep it secret.

  When Bohr toured the project’s research centres in England, he felt the full extent of the disillusionment he had heard about in Whitehall. British scientists bent hi
s ear for hours about how the government had wasted the lead that the MAUD committee had established, leaving them with a role in the construction of the weapon so feeble that it bordered on the humiliating. In the United States, Blackett was using his influence among British scientists there to try to persuade them not to join the American project, and was now arguing that trying to use a nuclear chain reaction to make a bomb was doomed to failure.18 Of the scientists who looked on the bright side, Chadwick was the most upbeat. As usual, he agreed with the line taken by Churchill – it was simply not feasible for Britain to build a British version of the weapon during the war, so he believed that he and his colleagues were fortunate to be involved in the Manhattan Project, as the knowledge they would gain would enable them to build the weapon when the war was over. Neither Chadwick nor any of his fellow scientists had been told that the original purpose of the project – to beat Hitler to the Bomb – was now almost defunct. They would soon find themselves working on nuclear weapons for an entirely different, and undeclared, political purpose.19 It was a classic example of what is now known as ‘mission creep’.

  It was not sensible to keep Bohr confined to the Tube Alloys head office – he wanted to be at the heart of the project and to make his voice heard where it would count. Groves wanted him in the US without delay and wholly on the American pay roll, though without full access to all the project’s secrets.20 Bohr ‘would not allow himself to be drawn in any way into the American orbit’, he promised Anderson, adding that he wanted to help ensure that the association between the British and Americans on the Bomb project was ‘a real partnership involving full and reciprocal sharing of scientific and technical knowledge’. This was just what Anderson wanted to hear, and he quickly arranged for Bohr to travel to the US to meet the leaders of the Manhattan Project and to visit its nerve centre, at a secret location known as ‘Site Y’.21 It would prove to be an enlightened strategy.