Making of the Atomic Bomb

  In December, before he first went out to Los Alamos, at a small reception at the Danish Embassy in Washington where he and Aage lived when they visited that city, Bohr had renewed his acquaintance with Supreme Court Associate Justice Felix Frankfurter. The justice was short, crackling, bright, Vienna-born, an agnostic Zionist Jew, an ardent patriot, a close friend of Franklin Roosevelt and one of the President’s longtime advisers. Bohr had met him in England in 1933 in connection with the rescue of the emigré academics; when Bohr visited Washington in 1939, the year Frankfurter was elevated to the Court, the two men developed what Frankfurter calls a “warm friendly relation.”1993 The December tea offered no opportunity to talk privately, but on his way out Frankfurter proposed to invite Bohr to lunch in chambers at the Supreme Court. He already understood that something was up.

  The justice was three years older than the physicist, born in 1882, the same year as Roosevelt. He had emigrated to the United States with his family in 1894, grown up on New York’s Lower East Side, graduated at nineteen from the City College of New York and made a brilliant showing at Harvard Law. He worked for Henry Stimson when Stimson was U.S. Attorney for the Southern District of New York, before the Great War, and in Washington when Stimson served as Secretary of War the first time, under William Howard Taft. Harvard invited Frankfurter to a professorship at its law school in 1914. He held that post until Roosevelt appointed him to the Supreme Court, but he was intensely active politically across those academic years, a one-man recruiting agency for the New Deal, a loyal friend who supported Roosevelt’s ill-advised 1937 scheme to pack the Court to overwhelm its conservative resistance to his innovative legislation.

  After Bohr returned to Washington from Los Alamos, in mid-February, the two men kept their appointment for lunch. Both left wartime memoranda describing the meeting. “We talked about the recent events in Denmark,” Frankfurter writes, “the probable course of the war, the state of England . . . our certainty of German defeat and what lay ahead. Professor Bohr never remotely hinted the purpose of his visit to this country.”1994

  Fortunately Frankfurter had heard about the project he called X. He says he heard from “some distinguished American scientists,” but he certainly heard from a distraught young Met Lab scientist who had penetrated all the way to Frankfurter and Eleanor Roosevelt in 1943 with complaints about Du Pont. “I had thus become aware of X—aware, that is, that there was such a thing as X and of its significance.” Since Frankfurter knew Bohr’s field he assumed X was the reason for Bohr’s visit:

  And so . . . I made a very oblique reference to X so that if I was right in my assumption that Professor Bohr was sharing in it, he would know that I knew something about it. . . . He likewise replied in an innocent remote way, but it soon became clear to both of us that two such persons, who had been so long and so deeply preoccupied with the menace of Hitlerism and who were so deeply engaged in the common cause, could talk about the implications of X without either of us making any disclosure to the other.

  Eminent jurist and eminent physicist thus easily dispatched that modest obstacle.

  “Professor Bohr then expressed to me,” Frankfurter goes on, “his conviction that X might be one of the greatest boons to mankind or might become the greatest disaster . . . and he made it clear to me that there was not a soul in this country with whom he could or did talk about these things except Lord Halifax [the British ambassador] and Sir Ronald Campbell [a British representative on the Anglo-American Combined Policy Committee].” Bohr picks up the narrative in third-person voice: “On hearing this F said that, knowing President Roosevelt, he was confident that the President would be very responsive to such ideas as B outlined.”1995

  Bohr had found his go-between. “B met F again one of the last days of March,” Bohr records in his wartime memorandum, “and learned that in the meantime F had had occasion to speak with the President and that the President shared the hope that the project might bring about a turning point in history.”1996 Frankfurter describes his meeting with Roosevelt:

  On this particular occasion I was with the President for about an hour and a half and practically all of it was consumed by this subject. He told me the whole thing “worried him to death” (I remember the phrase vividly), and he was very eager for all of the help he could have in dealing with the problem.1997 He said he would like to see Professor Bohr and asked me whether I would arrange it. When I suggested to him that the solution of this problem might be more important than all the schemes for a world organization, he agreed and authorized me to tell Professor Bohr that he, Bohr, might tell our friends in London that the President was most eager to explore the proper safeguards in relation to X.

  Much controversy surrounds this meeting, because Roosevelt later implicitly repudiated it. Why, if the President was worried to death about the postwar implications of the bomb, did he entrust a mission to the British to so informal an arrangement? He had not even met Niels Bohr. An answer to this question would answer a more substantive question: whether Roosevelt was in fact interested in exploring ideas of international control or whether he was already committed to perpetuating an Anglo-American monopoly (the Quebec Agreement implied commitment, and he had recently discussed cornering the world uranium and thorium markets with Groves and Bush).

  Why did Roosevelt entrust so important a mission to Bohr? In fact, the commission worked the other way around: Bohr had come to the United States representing the British, representing at least Sir John Anderson, who had encouraged his visit as much to promote discussing the issues Bohr had raised as to bolster the British Los Alamos mission. If the commission was informal it was no more so than any number of other backchannel arrangements between the British and the Americans. Roosevelt simply responded to what he took to be a British approach. He seems to have assumed—correctly—that British statesmen around Churchill were using Bohr to communicate to the President ideas about wartime and postwar arrangements to which Churchill was not yet committed. He responded candidly with loyalty to his British counterpart, Bohr adds: “F also informed B that as soon as the question had been brought up, the President had said it was a matter for Prime Minister Churchill and himself to find the best ways of handling the project to the benefit of all mankind, and that he should heartily welcome any suggestion to this purpose from the Prime Minister.”1998 The President would be happy to discuss new ideas for postwar relations, but the British would first have to convince the P.M.; Roosevelt would not deal behind Churchill’s back. Frankfurter implies this understanding: “I wrote out such a formula for Bohr to take to London—a communication to Sir John Anderson, who was apparently Bohr’s connecting link with the British government.”1999

  Complicating Bohr’s discussions, in March and later, was the question of what to do about the USSR. Bohr considered the question in the following perspective. Tell the Soviet Union soon, before the first bombs were nearly built, that a bomb project was under way, and the confidence might lead to negotiations on postwar arms control. Let the Soviet Union discover the information on its own, build the bombs and drop them, oppose the Soviets at the end of the war with an Anglo-American nuclear monopoly, and the likeliest outcome was a nuclear arms race.

  Bohr’s revelation of the complementarity of the bomb was far more fundamental than this contemporary political question. But the contemporary political question was an aspect of the larger issue and partly obscured it from view. The bomb was opportunity and threat and would always be opportunity and threat—that was the peculiar, paradoxical hopefulness. But political conditions would necessarily differ before and after it was deployed.

  At the end of March 1944, Bohr seemingly had a mandate from the President of the United States to talk to the Prime Minister of Great Britain. The British in whom Bohr had been confiding were properly impressed. “Halifax considered this development to be so important,” writes Aage Bohr, “that he thought my father should go to London immediately.”2000 Father and son crossed the Atlantic again, th
is time by military aircraft, in early April.

  Anderson had been working to soften Churchill up. The tall, dark Chancellor of the Exchequer, whom Oppenheimer describes as a “conservative, dour, remarkably sweet man,” sent the Prime Minister a long memorandum on March 21.2001 He suggested opening Tube Alloys to wider discussion within the British government. Echoing Bohr, he saw the possibility of international proliferation of nuclear weapons after the war. He thought the only alternative to a vicious arms race was international agreement. He proposed “communicating to the Russians in the near future the bare fact that we expected, by a given date, to have this devastating weapon; and . . . inviting them to collaborate with us in preparing a scheme for international control.”2002, 2003

  Churchill circled “collaborate” and wrote in the margin: “on no account.”

  When Bohr arrived Anderson wrote the Prime Minister again, going over the same arguments but adding that he now believed Roosevelt was attending the subject and would welcome discussion. He even supplied a draft message Churchill might send to initiate an exchange. The response was equally waspish: “I do not think any such telegram is necessary nor do I wish to widen the circle who are informed.”2004

  Churchill was in no mood to see Bohr; the Danish laureate cooled his heels for weeks. While he waited he heard from the Soviets. Peter Kapitza had written Bohr shortly after the Bohrs escaped from Denmark—the letter found its way from Stockholm to the Soviet Embassy in London—“to let you know that you will be welcome to the Soviet Union where everything will be done to give you and your family a shelter and where we now have all the necessary conditions for carrying on scientific work.”2005 After alerting the Tube Alloys security officer Bohr went to the embassy in Kensington Gardens to collect the letter; on his return he reported his conversation with the embassy’s counsellor. Amid much talk about the greatness of Russian science and how few friends Russia had counted before the war was the heart of the matter:

  The Counsellor then said that he knew that B had recently been to America, and B said that he had received from the journey many encouraging expressions of the wish for international cultural co-operation and that he hoped soon to come to Russia also. The Counsellor next asked what information B had received about the work of American scientists during the war, and B answered that the American scientists, just like the Russian and the British, had surely made very large contributions to the war effort which would no doubt be of great importance for an appreciation of science everywhere after the war. B thereafter told a little about the situation in Denmark during the occupation.2006

  Quickly changing the subject. But for Bohr the blunt question and Kapitza’s invitation to come to Moscow were enough to indicate that the Soviets had at least an inkling of the bomb project and might be working on their own. Which meant there was very little time left to convince them that a secret arms race had not already begun. He carried that urgency with him when he was called with Cherwell, finally, on May 16, to 10 Downing Street.

  “We came to London full of hopes and expectations,” Aage Bohr remembers. “It was, of course, a rather novel situation that a scientist should thus try to intervene in world politics, but it was hoped that Churchill, who possessed such imagination and who had often shown such great vision, would be inspired by the new prospects.”2007 Niels Bohr cherished that hope. His British friends had not prepared him.

  “One of the blackest comedies of the war,” C. P. Snow characterizes the disastrous confrontation.2008 The definitive account is from R. V. Jones, Cherwell’s protégé, who had helped make arrangements and who was surprised to find Bohr wandering a few hours later in Old Queen Street outside the Tube Alloys office:2009

  When I asked him how the meeting had gone he said: “It was terrible. He scolded us like two schoolboys!” From what he told me at that time and afterwards, it appeared that the meeting misfired from the start.2010 Churchill was in a bad mood, and he berated Cherwell for not having arranged the interview in a more regular manner. He then said he knew why Cherwell had done it—it was to reproach him about the Quebec Agreement. This, of course, was quite untrue, but it meant that Bohr’s “set piece” talk was thrown right out of gear. Bohr, who used to say that accuracy and clarity were complementary (and so a short statement could never be precise), was not easy to hear, and all that Churchill seemed to gather was that he was worried about the likely state of the post-war world and that he wanted to tell the Russians about the progress towards the bomb. As regards the post-war world Churchill told him: “I cannot see what you are talking about. After all this new bomb is just going to be bigger than our present bombs. It involves no difference in the principles of war. And as for any post-war problems there are none that cannot be amicably settled between me and my friend, President Roosevelt.”

  Bohr got only the bare thirty minutes of his scheduled appointment, most of which Churchill had monopolized. “As he was leaving,” Aage Bohr concludes, “my father asked for permission to write Churchill, whereupon the latter answered, ‘It will be an honour for me to receive a letter from you,’ adding, ‘but not about politics!’”2011

  “We did not speak the same language,” Bohr said afterward.2012 His son found him “somewhat downcast.”2013 He was angrier than that; in his seventy-second year, still stinging, he told an old friend: “It was terrible that no one over there”—England and America both—“had worked on the solution of the problems that would arise when it became possible to release nuclear energy; they were completely unprepared.”2014 And further, “It was perfectly absurd to believe that the Russians cannot do what others can. . . . There never was any secret about nuclear energy.”

  Churchill’s obduracy was compound but straightforward. He was up to his neck in preparations for the Normandy invasion; he sniffed conspirators encroaching back-channel and instinctively swatted them down; he resented the awe his colleagues accorded this certified great man (“I did not like the man when you showed him to me, with his hair all over his head, at Downing Street,” he gnawed at Cherwell afterward); he could not listen carefully enough, or was too certain of his own opinions, to be convinced that the bomb would change the rules.2015 A year later the seventyyear-old Prime Minister had budged no further. “In all the circumstances,” he wrote Anthony Eden in 1945, “our policy should be to keep the matter so far as we can control it in American and British hands and leave the French and Russians to do what they can. You can be quite sure that any power that gets hold of the secret will try to make the article and this touches the existence of human society. This matter is out of all relation to anything else that exists in the world, and I could not think of participating in any disclosure to third or fourth parties at the present time.”2016

  “He had always had a naive faith in ‘secrets,’ ” concludes C. P. Snow. “He had been told by the best authorities that this ‘secret’ wasn’t keepable and that the Soviets would soon have the bomb themselves. Perhaps, with one of his surges of romantic optimism, he deluded himself into not believing it. He was only too conscious that British power, and his own, was now just a vestige. So long as the Americans and British had the bomb in sole possession, he could feel that that power hadn’t altogether slipped away. It is a sad story.”2017

  Bohr wrote Churchill on May 22; the letter was circumspect but political after all and conveyed what he had not been allowed to convey at the meeting: “that the President is deeply concerned in his own mind with the stupendous consequences of the project, in which he sees grave dangers, but also unique opportunities.” Bohr did not spell out these opportunities. He even seemed to step back from offering advice: “The responsibility for handling the situation rests, of course, with the statesmen alone. The scientists who are brought into confidence can only offer the statesmen all such information about technical matters as may be of importance for their decisions.”2018 Those technical matters, however, Bohr made sure to note, included the probability of proliferation and of bigger bombs—he had learned of
the Super at Los Alamos.

  Apparently Churchill did not trouble himself to respond.

  Bohr stayed on in London for several more weeks. He was thus on hand for D-Day, Tuesday, June 6, 1944. “The greatest amphibious assault ever attempted,” Dwight D. Eisenhower, the Supreme Allied Commander, called that invasion of Europe across the English Channel with an initial force of 156,000 British, Canadian and American soldiers supported by 1,200 warships, 1,500 tanks and 12,000 aircraft. By the time Bohr and his son left England at the end of the week to return to the United States the Allies had secured the invasion beaches and begun advancing inland with a force bolstered now to 326,000 men. “The way home,” Eisenhower instructed his armies, “is via Berlin.”2019

  For Bohr the way home was via Washington. He reported his dismal experience with Churchill to Felix Frankfurter on June 18. Frankfurter immediately carried the news to Roosevelt, who was amused to hear another tale of Churchillian pugnacity:

  About a week later F told B that this information had been heartily welcomed by the President who had said that he regarded the steps taken as a favourable development. During the talk the President had expressed the wish to see B, and as a preliminary step F advised B to give an account of his views in a brief memorandum.2020

  The Bohrs turned to the task as Washington steamed, the last days of June and the first days of July dawning in the high eighties and sweltering above 100° by afternoon. Aage Bohr recalls the document’s preparation:

  It was worked out in the tropical heat of Washington and, like all my father’s work, underwent many stages before it was ready for delivery. In the morning, my father would usually bring up new ideas for alterations that he had thought out during the night. There was no secretary to whom we could entrust such documents, and therefore I typed them; meanwhile my father darned socks and sewed buttons on for us, a job which he carried out with his usual thoroughness and manual skill.2021