by Ray Monk
In order, perhaps, but – to the increasing dismay of the British – still not in effect. At the end of August, Mark Oliphant flew to the US to see what was happening. ‘If Congress knew the true history of the atomic-energy project,’ Leo Szilard once said, ‘I have no doubt but that it would create a special medal to be given to meddling foreigners for distinguished services, and Dr Oliphant would be the first to receive one.’ In Washington, Oliphant called on Briggs and was ‘amazed and distressed’ to find that ‘this inarticulate and unimpressive man’ had put the MAUD Committee’s reports in a safe, without showing them to the other members of the uranium committee. As soon as he could, he met with the uranium committee and, to the shock of some of them, spelled out the possibilities of using fission to make an explosive. It was the first time some of the committee had heard the word ‘bomb’ used in this context. One of its members, Samuel Allison, later recalled: ‘I thought we were making a power source for submarines.’
From Washington, Oliphant flew to California to meet Lawrence, who, he had reason to believe, had a greater sense of urgency about the project than prevailed among the government scientists. On 21 September 1941, Lawrence drove Oliphant up ‘Cyclotron Hill’ to see the site of the still-to-be-built 184-inch cyclotron. When they returned to Lawrence’s office, they were joined by Oppenheimer. Assuming that Oppenheimer was privy to the official secrets that he and Lawrence had been discussing, Oliphant continued to talk about the MAUD report, about the optimism that the British scientists had expressed concerning the possibility of building an atomic bomb, and about the cooperation between Britain and the States on the research and development of the bomb. Noting that Lawrence had begun to look extremely uncomfortable, and registering the shocked expression on Oppenheimer’s face, Oliphant realised that he had just revealed to Oppenheimer for the first time the existence of a project to build an atomic bomb. Clearing his throat, Oppenheimer suggested to Oliphant that it might be advisable not to continue this conversation, since he was not involved with the project. ‘But that’s terrible,’ replied Oliphant. ‘We need you.’
By thus passing this information on to him, Oliphant may possibly have guaranteed that Oppenheimer would become involved in the project. For, even if it had not been decided that Oppenheimer’s theoretical skills would be invaluable to the project, he now knew too much to be left out.
* * *
fn41 Take the fifty-six protons of barium from the ninety-two of uranium, and you are left with thirty-six, the atomic number of krypton.
fn42 While most people in California anglicised it to ‘Oppie’, Chevalier insisted on keeping to the Dutch original of the nickname.
fn43 See here.
PART III
1941–1945
11
In on the Secret
AFTER HE HAD let slip to Oppenheimer the Allies’ most important and most closely guarded military secret, Oliphant returned to Washington, leaving a written summary of the MAUD report’s findings with Lawrence. In Washington, Lawrence had arranged for Oliphant to meet Bush and Conant, but from both Oliphant received a rather frosty reception. Adopting a somewhat stricter approach to official secrets than had prevailed in California, neither Bush nor Conant would admit to knowing anything about the MAUD report and both gave Oliphant the cold shoulder. To Bush, Conant dismissed Oliphant’s information as ‘gossip among nuclear physicists on forbidden subjects’, and remarked testily: ‘Oliphant’s behaviour does not help the cause of secrecy.’
The encounter between Oliphant and Bush and Conant reveals a fundamental difference between the priorities of Britain and the United States at this time. For the British, maintaining strict secrecy was of secondary importance to the crucial task of building an atomic bomb before the Germans, who, they had reason to believe, were pressing ahead with their own atomic-weapons programme.
From the perspective of the US, things looked rather different. America was not yet at war with Germany, nor was the Soviet Union yet its ally. Indeed, in so far as the Americans regarded themselves as being at war in the autumn of 1941, it was a war of espionage against the Soviet Union. The truly breathtaking extent of Soviet espionage – industrial, scientific and military – during this period would not become fully apparent until many years after the war, but the US authorities already knew enough to be certain that the Russian embassy in Washington and the consulates in New York and San Francisco were operating as centres of a major spying operation. Using an elaborate system of ‘legals’ and ‘illegals’ – the former operating under their own names, the latter working under cover of false names and disguises – and employing a mixture of people working through the American Communist Party and others working directly for the Soviet Union, a vast amount of information was being collected from manufacturing companies, universities, military bases and government offices and sent via official cables to Moscow.
In Britain, the Soviet espionage operation had been, and continued to be throughout the war, extraordinarily effective. The ‘Cambridge Five’ – Anthony Blunt, Guy Burgess, Donald Maclean, Kim Philby and John Cairncross – alone were responsible for the handing over to Moscow of a substantial number of top British military secrets. Partly, no doubt, because of their status as accepted members of the British social and educational elite, they were, with only minimal security checks, appointed to the kind of positions that gave them access to the Allies’ most closely guarded documents (Blunt, Cairncross and Philby worked for British intelligence, while Maclean and, intermittently, Burgess were employed by the Foreign Office). Through Cairncross, for example, the Soviets received, just a week or so after the final meeting of the MAUD Committee, a full account of that meeting and a copy of its final report.
Neither Britain nor the US knew about the activities of these five until after the war. They were exposed by an operation that the US had put into place precisely because of their suspicions of the Soviets. This was the so-called ‘Venona’ project, in accordance with which the US telegraph companies were instructed to keep a copy of every cable sent from the US to Moscow. These messages, hundreds of thousands of them, were preserved and studied and, after many of them had been decoded, provided the US authorities with a detailed picture of the astonishing extent and success of Soviet espionage.
The decoding, however, could not be done in time to prevent most of the espionage that occurred during the war, and the US had to rely chiefly on the counter-intelligence efforts of the FBI. While the British lacked the manpower, and to some extent the will, to do very much about Soviet espionage, the US could afford to invest the vast sums it took to employ several thousand FBI agents to try to prevent their secrets from being handed over to Moscow.
Because the FBI knew that the American Communist Party played a key role in the information-gathering efforts of the Soviets, they naturally centred their counter-intelligence effort on Communist Party members and people close to them. Thus it was that, while Oliphant was eagerly revealing to Oppenheimer the secret of the British and the American atomic-bomb projects, the FBI were keeping a file on him.
At this time, though the FBI regarded Oppenheimer as suspicious, they did not treat the surveillance of him as a particularly high priority. They may have kept a file on him, but they did not – as they did with people identified as senior figures in the Soviet espionage network – have him followed, bug his phone or install microphones in his house. And, in fact, the file they opened on him in March 1941 contained, six months later, very little. It recorded: 1. his attendance at Chevalier’s home at a meeting in December 1940, at which Isaac Folkoff and William Schneiderman were also present; 2. Folkoff’s reference to him as ‘the big shot’; 3. his subscription to the Communist Party newspaper, People’s World; and 4. his membership of several Communist front organisations. And that was about it. It was more than enough to persuade J. Edgar Hoover that Oppenheimer needed to be watched, but it fell a long way short of suggesting that he was engaged in any kind of espionage. Of course, before his
meeting with Oliphant, Oppenheimer, even if he had wanted to hand over secret information to the Soviets, would have been unable to do so, since he did not have access to any secrets. In the months after that meeting and, indirectly at least, as a result of that meeting, that was to change drastically.
With Ernest Lawrence (if not with Bush and Conant), Oliphant had succeeded in his aim of using the MAUD Committee’s findings to instil a sense of urgency with regard to the development of an atomic bomb, and, in his desire to hurry the project along, Lawrence had an influential ally in Arthur Compton. On 25 September 1941, somewhat to his annoyance, Conant was subjected to what he described to Bush as an ‘involuntary conference’ on the atomic bomb with Lawrence and Compton. This took place at Compton’s home in Chicago, where Conant was staying as a guest while attending the celebrations commemorating the fiftieth anniversary of Chicago University. Unknown to Conant, Compton had invited Lawrence, who was also in Chicago for the celebrations, to come to his home to present to Conant his case for pressing urgently ahead with the development of the bomb. After taking the opportunity to reprimand Lawrence for allowing the secret of the bomb to be given away to Oppenheimer, Conant listened to Lawrence’s arguments for adopting the MAUD Committee’s findings and working with the British on building the bomb. Then, turning to Lawrence, Conant said: ‘Ernest, you say you are convinced of the importance of these fission bombs. Are you ready to devote the next several years of your life to getting them made?’ After a moment’s hesitation, Lawrence replied: ‘If you tell me this is my job, I’ll do it.’
Though it had been discussed unofficially by American scientists for months, and Lauritsen had supplied officials with a precis, the MAUD report was not officially delivered to Conant until 3 October 1941. Six days later, Bush presented its findings to President Roosevelt, whose response was to set up a high-level policy group – consisting of Bush and Conant, together with the Vice President, the Secretary of War and the Army Chief of Staff – who would henceforth be responsible for the management of the atomic-bomb project, acting on advice from Arthur Compton’s committee. In response to this development, Compton called a meeting of his committee for 21 October in Schenectady, in upstate New York. A week before the meeting, Lawrence cabled Compton to say: ‘Oppenheimer has important new ideas. Think it desirable he meet with us Tuesday. Can you arrange invitation?’ After a second request, in which Lawrence emphasised that he had ‘a great deal of confidence in Oppenheimer’, Compton capitulated and agreed to allow Lawrence to bring him.
Within a month of his impromptu meeting with Oliphant, therefore, Oppenheimer had gone from being completely ignorant of, and excluded from, the US atomic-bomb programme to being right at the heart of it. This seems to have resulted in a flurry of what the FBI, at least, regarded as extremely suspicious Communist Party activity on Oppenheimer’s part. On 3 October 1941, the agency learned from a ‘reliable confidential informant’ (a wire tap on Folkoff’s phone) that Folkoff had been in touch with Oppenheimer to advise him that he would not be able to meet him at the weekend and had instead arranged for him to meet Steve Nelson. Three days later, from the same ‘informant’ the FBI learned that Nelson had contacted Folkoff to say that he had received $100 from ‘him’. Then, on 14 October, a mere week before the Schenectady meeting, the wire tap revealed that Oppenheimer had contacted Folkoff to ask him to arrange for Rudy Lambert (the head of the California Communist Party labour commission) to contact him and to tell him that ‘Steve’ had contacted him and given him a message for Folkoff.
There is no record of Oppenheimer’s meeting with Lambert – nor even any confirmation that it took place – nor is there any way of knowing what message Steve Nelson wished to pass on to Folkoff via Oppenheimer. Coming at precisely the moment when Lawrence was pressing for Oppenheimer to be invited to a secret meeting to discuss progress on the atomic bomb, it is natural to wonder whether Oppenheimer might have been passing on information about this meeting to people who would then be able to inform Moscow. On the basis of the available evidence, however, it seems more likely that Oppenheimer’s purpose was to let Folkoff know that henceforth his contacts with the Party would be severely reduced.
Oppenheimer knew (from Frank’s experience, for example) how damaging it could be to one’s career to be perceived as a communist, and there are many signs that, by the autumn of 1941, what he wanted more than anything was to be involved in government work related to the war – work which, he well knew, was wholly incompatible with close associations with the Communist Party. In his letter to Willie Fowler in the spring of 1941 mentioned earlier, Oppenheimer had written: ‘I think surely if I were asked to do a job I could do really well and that needed doing I’d not refuse.’ The sense one has from Oppenheimer’s letters of the spring and summer of 1941 is that he felt excluded from what was important, an impression supported by the Berkeley chemist Martin Kamen, who recalls that, though Oppenheimer had previously been the person everybody spoke to about their research, in 1941 this began to change:
All of a sudden, nobody’s talking to him. He’s out of it. There’s something big going on over there [at the Rad Lab], but he doesn’t know what it is. And so he was getting more and more frustrated and Lawrence is very worried because he feels that, after all, Oppenheimer can certainly figure out what’s going on, so the security is nonsense to keep him out of it. Better to have him in. And I imagine that’s what finally happened; they said it’s easier to monitor him if he’s inside the project than outside.
Oppenheimer himself said that he was ‘not without envy’ of the men he knew who had gone off to work on radar or other aspects of military research, ‘but it was not until my first connection with the rudimentary atomic-energy enterprise that I began to see any way in which I could be of direct use’.
As usual, Oppenheimer’s behaviour was ambiguous and difficult to interpret. If he had wanted to avoid political controversy in order to ‘be of direct use’, it was rather odd of him, on 13 October 1941, to write a strongly worded letter of protest to Senator F.R. Coudert, who was co-chairman of the committee appointed by the State of New York to investigate communist infiltration of the New York City college system. After making the perfectly reasonable point that the Bill of Rights ‘guarantees not the right to a belief, but the right to express that belief, in speech or in writing’, and that therefore the teachers accused of communism were engaged in ‘practices specifically protected by the Bill of Rights’, Oppenheimer could not help himself ending his letter with some straightforward and, in the context, surely superfluous, abuse: ‘It took your own statement, with its sanctimonious equivocations and its red baiting, to get me to believe that the stories of mixed cajolery, intimidation and arrogance on the part of the committee of which you are the chairman, are in fact true.’ This is not the tone of a man determined to keep a low profile and avoid offending the political establishment. The vitriol in the letter, however, might be seen as further evidence of Oppenheimer’s frustration and anxiety over the possibility that he might be excluded from war-related work because of his connections with the Communist Party, and his anger at the implied suggestion that he was not entirely loyal to the US.
A week after thus registering his disapproval of those who would deny communists their constitutional rights, Oppenheimer was travelling with Lawrence across the US, from Berkeley to Schenectady, to take part in a meeting that would turn out to be an important milestone in the Allied project to build an atomic bomb. The meeting opened with Lawrence reading Oliphant’s summary of the MAUD report. Compton then reported on various meetings that he had had with leading scientists, at which he received the latest information on key scientific questions relating to the bomb from those most qualified to give it. One assumes that much of this information would have been new to Oppenheimer.
Compton reported that in his meetings with Fermi he had received an estimate of the critical mass of U-235 that put it at about 100 pounds. This was considerably more than the Frisch–Peie
rls estimate, but still low enough to make the bomb a practical proposition. But, whether one needed two pounds or 100 pounds, the extraction of U-235 from natural uranium remained an extraordinarily difficult task. Compton’s advice on how best to tackle this problem came from the Nobel Prize-winning chemist Harold Urey, who told Compton about the various methods of separating the fissionable isotope, all of which would require a massive investment in time and manpower if they were to produce enough U-235 to make a bomb.
The most promising methods of separation, Urey told Compton (and Compton reported to the Schenectady meeting), were gaseous diffusion and centrifugal separation. The former requires the uranium to be converted from a metal into a gas and then forced through the microscopic holes of a filter, or ‘barrier’. Because the U-235 isotope is slightly lighter than U-238, it will pass through the barrier more readily, so that the barrier will act as a way of ‘enriching’ the uranium – that is, increasing the proportion of U-235. Among the many problems with this method are that the gas is extraordinarily corrosive and the process has to be repeated many times, making it laboriously slow. At the time of Compton’s meeting with Urey, only microscopic amounts of enriched uranium had been produced by this method. The idea that it might furnish the basis for production of the isotope on an industrial scale looked fanciful.