In a large corniced office on the fifth floor of Leconfield House, MI5’s director general, Percy Sillitoe, faced his deputy, Guy Liddell, over the gnawing question of how to dispose of Klaus Fuchs. Sillitoe subscribed to the argument for interrogation championed by the chief of B Branch, Dick White. Liddell expressed concerns about possible repercussions of a confession, most notably, that this accomplished physicist, steeped in British and American nuclear research, would immediately defect.
Sillitoe and Liddell were very different spirits, with further cause for tension between them in that Liddell had every reason to believe that he would be named to head the spy agency when, instead, Sillitoe was given the position in 1946.
The director general had been a chief constable—famed and knighted for wiping out gangs and modernizing police forces in large cities. To make sure the police identified each other in a raid, he fashioned “Sillitoe Tartan,” the black-and-white checkerboard bands they wore. He was a policeman’s policeman, not reared in intelligence or the lifestyle of London’s old-school clubs.
Those bastions of privilege had been part of Liddell’s life for three decades, first with Scotland Yard and since 1931 with MI5, mostly in counterespionage. In 1933, he had visited Berlin, met many of the top Nazis, and listened to dubious stories about the communists. He knew the territory quite well.
Sillitoe focused on the potential upside of an interrogation; Liddell focused on the downside. The latter argued that they should avoid a confrontation and use Emil’s move as an excuse to get Klaus out of Harwell and transferred to a university. It was a logic that harked back to the days of war, when ability topped politics and punishment, if any, was a quiet reassignment or—worst case—a dismissal. But Sillitoe, the policeman, wanted confession and prosecution.
Arnold’s assessment—that Fuchs’s relating confidences about Emil was “most unusual since he is normally the most reticent and self-sufficient of men”—had captured Sillitoe’s imagination, just as Fuchs’s reaction to possible Russian pressure had captured White’s. They saw themselves stalking a weakened prey.
After the meeting, Sillitoe cabled Patterson in Washington about briefing the FBI on a revised plan using Emil’s move “to delve further into FUCHS’ mind.” That is, Arnold would talk with Fuchs, bring up possible pressure by the Russians, and then go into “the direct question of whether Fuchs had ever come into contact with Russians.” They hoped Fuchs would “unburden himself.” If not, at least they could observe his thinking. A caveat: the FBI shouldn’t construe this move as an alternative to gathering more evidence, particularly from Kristel and Bob Heinemann.
The next day, when Arnold heard about the idea, he was hesitant. Interviewing Fuchs could undermine his personal relationships with staff if his role were known. Weighing whether Fuchs would confess, he saw “a most carefully calculating man” who wouldn’t have “an emotional breakdown.” Once Fuchs knew the evidence against him, his personal interest would be a heavy factor.
On the other hand, Arnold thought he himself had the best chance of getting a confession. If Fuchs didn’t open up voluntarily, he could formally interrogate him relying on their friendship, established trust, and Fuchs’s nervous nature. He judged his chances of getting Fuchs to come clean at fifty-fifty.
Fuchs’s ultimate fate was not MI5’s to decide. The security agency gathered facts and made recommendations and, if possible, gained a confession. The decision on what might follow belonged to the Ministry of Supply, its director Sir Archibald Rowlands, and its controller of production (atomic energy) Sir Charles Portal (Perrin was his deputy)—and overall to the prime minister.
Martin laid out a briefing document for Rowlands and Portal with an analysis of objectives, methods for achieving them, and effectiveness. Options for action were (1) no interrogation with retention at Harwell or transfer to another post; or (2) interrogation with either prosecution, dismissal, or retention. Sillitoe advised that only interrogation resulting in prosecution, not simply dismissal, secured all objectives.
While MI5 waited for a response, the Listeners heard Fuchs mention his passport, an allusion that made a nervous Robertson more so. Arnold assured him that it was innocent. Fuchs had an administrative request for his birth certificate. His passport was the substitute.
In the meantime, Patterson sent Martin the FBI’s official agreement for an interrogation provided it safeguarded the Venona source. At least one hurdle was crossed.
On November 15, 1949, MI5 officers gathered to “clear our minds,” as Liddell put it in his diary. They were to meet with Rowlands and Portal the next day at the Ministry of Supply at Shell Mex House. To clarify their talking points, Martin wrote up a fourteen-point statement that summarized the other countless memos. It boiled down to one question for Rowlands and Portal: “How important is the need to prevent his defection?” It was an outcome that MI5 couldn’t absolutely prevent. For just that reason, Liddell held to his position that edging Fuchs out of Harwell was a better option than a confession.
Martin’s minutes of the meeting on the sixteenth filled only one page. The Ministry of Supply first represented the concerns of Harwell’s director, John Cockcroft, that Fuchs’s value to Harwell was “extreme.” He didn’t want to lose him. If not a threat to security, Fuchs could be retained at Harwell; if he went to Russia, that country’s gain would be considerable. MI5 turned the argument and convinced Rowlands and Portal that the only way to ensure Fuchs’s reliability was interrogation, that “the advantages to be gained from a successful interrogation outweighed the risks involved.”
That same day, Sillitoe briefed the prime minister, who agreed with the strategy of interrogation but requested it be postponed for a fortnight until Cockcroft returned from a trip. All agreed.
Robertson determined that other than official trips, which were often with other scientists, Fuchs had left the Harwell area six times since September. The twenty-four-hour net had not produced the slightest odd conversation or unexpected meet up, except when he was with Erna. How much surveillance was needed?
MI5 cut back to not pursuing Fuchs outside London when MI5 was “reasonably sure where he is going and why.” A little later, they did the same with telephone checks, suspending the Listeners’ services—although not the recording—in Newbury from midnight to 8:30 a.m.
Meanwhile, Robertson delved more deeply into Fuchs’s past. He twice noted the name Ronald Gunn in Fuchs’s file, the man who had sponsored his naturalization filings in 1939 and 1942 and in whose home he had stayed while studying in Bristol. When Robertson queried the Registry, he found that in 1940 MI5 had opened a security file on Gunn that was filled with informants’ rumors but no mention of Fuchs. Reports described Gunn’s connection with the Imperial Tobacco Company, as well as the trips he and his wife had made to Russia in July 1932 and June 1936. It wasn’t these trips that had drawn the security service to them, though. It was their mail.
An inquisitive postman had informed the Bristol police that Gunn was “in correspondence in suspicious circumstances with aliens,” indicating “leanings toward ‘either Communism or Nazism.’” His file held the names of “Communists or near-Communists” collected from the addresses on the envelopes. Robertson tracked one of these names to a list of veterans of the International Brigade in Spain available for national service during the war. That list had been compiled by the ubiquitous Hans Kahle.
Robertson requested a mail warrant and telephone tap on Gunn. He asked the Bristol constable to relay any findings, warning that Gunn could be involved in “subversive activity on behalf of Soviet Russia,” although, he acknowledged, he had no evidence. Robertson assumed that during the time he had stayed with the Gunns, Fuchs adhered “to the same Communist views.”
Also continuing to delve into Fuchs’s past was Arthur Martin. On November 21, he and a few others sat down with Frank Kearton, Fuchs’s former co-worker in New York. First, they told Kearton that Fuchs was a Soviet spy. An astonished Kearton thought Fuchs the least likely person to suspect. To him Fuchs had been completely absorbed in his work, an extension of Rudi Peierls’s “brain,” and happy to remain in the background. He had a small furnished apartment and little social life and showed no interest in politics. Not the same Fuchs as now, he added. Kearton had witnessed, as had others, a transformation in Fuchs, whose growing position in the field had not only increased his confidence but widened his interests.
The men from MI5 took Kearton through Fuchs’s “movements,” specifically the possibility of his knowing about a return to the U.K. in the summer of 1944. Kearton thought that Peierls might have told him about the prospect of a team in the U.K. working on diffusion and that Fuchs could guess that he might be sent back. Kearton didn’t know when the decision to transfer Fuchs to Los Alamos occurred, but he knew that Peierls went there at the end of June. Kearton could imagine that once there, Peierls realized how much he needed Fuchs. If Peierls made a request, Fuchs would have heard about it around mid-July.
As for the “friends and relatives” category, Kearton volunteered that Fuchs had family someplace outside New York City, at least a train ride away, and that he visited them on two weekends. Kearton didn’t know of any friends, but he did know that a group of researchers at Columbia was a contractor on the project and used his results. His contact there was someone named Cohen.
On the “clerical staff” side, Kearton listed a couple of secretaries and at least one “machine computer,” a person who performed the calculations that Fuchs, Peierls, or Kearton handed her. This woman had a degree in mathematics and was Russian, her parents being recent émigrés. She didn’t generally see finished documents, but she could have gained access to and would have understood some of the material. He thought that only he, Fuchs, and Peierls would have had unrestricted access. Even if the typists would have had access, they wouldn’t have understood what they were seeing. In fact, they had no knowledge of the mission’s purpose. The MSN series of papers, including the one passed along to the Russians, was for the Americans, in particular the group at Columbia.
Kearton offered his own theory about potential spies. If there was one, it was Skyrme, whom he described as “a person likely to have strong convictions, that he almost certainly did develop social contacts in New York, that he got involved in several minor ‘scrapes’ and that he was generally ‘rather odd.’” MI5 listened but, given past experience with scientists’ assessment of their own, remained jaded and unconvinced.
Kearton gave them nothing to contradict the information they already had. But the Russian machine computer was a new complication. Martin immediately cabled Washington with the information, including the fact that the Americans had rejected Peierls’s recommendation for her employment—probably at Los Alamos—on security grounds. Next, he and John Marriott, an MI5 officer, related the discovery of the Russian machine computer to Liddell, as well as the possibility of her contact with university students. But as Liddell noted, “Neither Martin nor Marriott are in the least shaken in the belief that FUCHS is the man we are after.”
The next day Martin received a list of the seventeen MSN papers and an overnight response from Washington about the female Russian mathematician. Neither the embassy nor the FBI knew her identity, and finding it wouldn’t be easy. For the embassy, an extensive file search might be a security risk. For the FBI, a trace required either a name or manpower in New York to find it. They wouldn’t do more unless MI5 deemed it essential, which it didn’t.
Meanwhile, Fuchs kept going about his normal life. In mid-November, he and Peierls went to a three-day conference on elementary particles in Edinburgh organized by his former mentor Max Born. They caught the night train in London—Robertson didn’t have them followed—and from Peierls’s daily phone calls to his wife the Listeners reported that the two sat together at the conference, hung around together talking physics, and one night went to a terrible movie.
The Watchers did pick up Fuchs on his return to King’s Cross at 7:10 a.m. They noted his trip to Paddington Station, a phone call, and breakfast at the station. A man joined him. They ate and paid the bill, and Fuchs took the 9:15 train to Didcot. The Watchers followed his breakfast companion, and they found that his life was about as exciting as Fuchs’s. He went to the men’s room, took the tube to Trafalgar Square, visited a number of bookstores specializing in scientific texts, ending up at a branch of Butterworth’s where he spent the next three and a half hours in the Scientific Research Department. After having a bite to eat and getting his backpack from the coatroom at Paddington, he boarded the 5:35 p.m. train to Didcot. Such was the humdrum of a researcher at Harwell—and those who watched.
A few days later, the esteemed Danish physicist Niels Bohr arrived to give a lecture. Because Cockcroft was busy, Fuchs played host, driving him to Cambridge and then to London to see James Chadwick, the man who had directed the British mission in America during the war.
On November 25, Martin cabled Patterson in Washington that “all necessary clearance has been obtained for the interrogation.” Three weeks later, MI5 officers gathered along with Perrin. They decided that Jim Skardon, their top interrogator, would meet with Fuchs on Wednesday, December 21. If he wanted to confess and needed assurances, they authorized Skardon to tell him that “his position can only be improved by complete frankness.” If they were forced to dismiss him from Harwell, they would give Emil Fuchs’s move to Leipzig as the reason, ideally blunting any objections from colleagues. With his new chair at the University of Liverpool, Skinner would probably welcome Fuchs there.
Dick White outlined the strategy, saying that Skardon should accuse Fuchs of being a spy and focus on his activities in New York. Skardon, White argued, needed to convince Fuchs that they knew he was a spy and that the inquiry didn’t arise simply because the Russians had detonated a bomb. Once again, there were concerns that the solidity of their evidence against Fuchs might compromise the long-standing American decryption program Venona.
Robertson put the Watchers and Listeners on alert for the twenty-first, not only for Fuchs, but for Yapou, Malleson, and Peierls as well. He established that Fuchs should not be detained if he were to leave the country before the interrogation. If the outcome of the interrogation was unfavorable, however, the Metropolitan Police (Special Branch) was “to detain FUCHS on any pretext if he is seen to be intending to leave the country.”
On December 21, Skardon took the train from Paddington and arrived in Didcot at 10:27 a.m. Arnold met him and drove to Harwell, where Arnold introduced him to Cockcroft. The latter had been briefed on the interrogation and possible reactions.
Robertson gave Arnold strict instructions not to forewarn Fuchs. So, Arnold came to Fuchs’s office around 11:00 and asked the physicist to accompany him. Someone wanted to speak to him about his father. Arnold walked with Fuchs to his office, introduced him to a tall, thin man named Jim Seddon (Skardon’s alias), and departed. Skardon opened up by explaining the security risk with his father moving to Leipzig. Fuchs then described his youth in Germany for over an hour. Suddenly, in the midst of this recitation, Skardon broke in and accused him of spying. Fuchs, somewhat stunned, replied, “I don’t think so.” Skardon continued to prod him until they broke for lunch at 12:45. Skardon wanted Fuchs to eat alone so that he could take time to reflect on what he had said.
Fuchs had other plans. The controlled and contained Fuchs, seemingly unfazed, went to the Skinners’, where Erna fixed him a lunch of soft foods. Having broken the plate for his front teeth, he was in significant discomfort. He called a dentist in Oxford to schedule an appointment, then went back to Arnold’s office.
In the afternoon, Skardon made it clear that the Ministry of Supply planned to remove him from Harwell because of his father. The Ministry didn’t know about the spying, though, and with a favorable report from him on his espionage activities, he might be able to stay at Harwell. The interview ended at 3:45.
Shortly after the interrogation broke up, Skardon called Leconfield House to say that Fuchs had confirmed much of what was known about him but denied being a spy. He then returned to London for a debriefing at 8:00 p.m. Robertson alerted the Listeners, Watchers, and Arnold to pay special attention to Fuchs’s reactions and movements.
The Listener on Fuchs’s office tap recorded that he seemed preoccupied on his return to his office. When a man came into his office reminding him of the division’s Christmas tea party, he departed and returned an hour and a half later. Then he left for home. Part of the evening he spent at the Skinners’. The rest of the evening was a blank. He wasn’t home by midnight, when the Listeners signed off. When he came in wasn’t recorded.
Deputy Chief Guy Liddell summarized MI5’s evening meeting with Skardon in his diary:
He [Fuchs] went over the whole ground, beginning with his early career, FUCHS admitted everything that we knew and, in fact, volunteered the information with certain additions. He had been associated with the KPD in his activities against the Nazis and after Hitler came into power he went to Paris where he had been in touch with Otto Katz and others. He had not, however, engaged in any such activities in this country, to which he was extremely grateful for the hospitality that it had extended to him, and for his naturalisation. Finally, Skardon came to the point, when he suggested that FUCHS had been passing information to the Russians. FUCHS smiled and said he did not quite understand. Skardon then put the point quite bluntly, when FUCHS denied flatly that he had ever done anything of the kind; he could not see why he should want to. Skardon then took him very carefully over the ground during the period when he was in America, and told him that our information was positive and that we could not disclose our informants, and said that if it was not FUCHS it “could only be his twin brother.” FUCHS said that he could offer no explanation as to how this mistake occurred. He admitted having visited his sister and even possibly to have taken papers with him; he could not conceive, however, that his sister would have betrayed him, even if she had an opportunity to do so.
Liddell further noted that when Skardon asked Fuchs why he went to see Arnold, Fuchs explained that his father was very outspoken, and if he was dissatisfied with the “Soviet zone,” he could make a fuss, even be arrested. He wanted Arnold to know of this possibility. He hadn’t recognized the potential for pressure on himself. Liddell’s conclusion:
FUCHS demeanor throughout was wholly consistent with guilt or with his innocence and we are, therefore, left with an extremely awkward situation on our hands.
The next morning, the Listeners came back on at 8:00 and heard Fuchs get up at 8:45. Erna’s call to him mid-morning at the office centered on herself, telling him that “she didn’t know how she was going to get through the day until 3:20 when ELAINE [her daughter] went.” Her remedy was lunch with him, suggesting scrambled eggs because of his teeth. She relayed an interesting piece of information. She “told him what a heavy sleeper he was—she had telephoned for about 11/2 hours the night before about 2 a.m.!”
After midnight the microphone in his house recorded a knock on the front door that he also didn’t answer.
The bugs and phone checks left many unanswered questions. Who knocked on the door? Was he at home when Erna called at 2:00 a.m.? He could have been. Sometimes, in the middle of the night, he didn’t answer her calls. Did he go someplace after visiting her? Did he simply drive around and ponder?
MI5 did not address these mysteries the next day, and the Watchers and the Listeners contributed nothing more. MI5’s records focused on the outcome of the interview.
Martin boiled it down in a cable to Washington:
FUCHS volunteered or admitted all facts except those deduced from [VENONA].
He flatly denied espionage and admitted no contacts which might suggest he was unconscious source.
We shall re-interrogate.
Meeting with Directorate Atomic Energy December 28th will decide disposal.
Please inform F.B.I. Stress value of any new information on network they may have.
No one questioned Fuchs’s ease of delivery. From Skardon’s notes his presentation seemed smooth, organized, and lucid, rehearsed almost—especially his recitation of his background. No unintentional slips of names or details. No entanglement in a web of lies. No crack for MI5 to widen. Skardon’s accusation that he had spied did make him pause. But a bit of a surprised response would be expected.
The next day Perrin came over to Leconfield House to talk with Liddell. They decided that the negative outcome required an analysis of the evidence—two columns, with the raw information in one and MI5’s explanation of each piece in the other. Perrin wanted to separate accusations of Fuchs’s spying from the question of what to do with him, and he wanted to resolve the latter quickly.
At the embassy in Washington, Patterson reacted with disappointment. Complying with Martin’s request, he spent several hours at FBI headquarters searching for anything new to help but came away empty-handed. He ventured to Martin that although Fuchs’s guilt wasn’t definite, all signs still pointed to him.
Most of MI5 felt even more certain than Patterson. The 10:30 meeting on the twenty-eighth at Shell Mex House included a full roster: Portal, Cockcroft, Perrin, Liddell, White, Skardon, and Martin. Skardon reviewed the information from the interrogation, and others dissected the evidence.
Martin’s minutes noted a difficult moment when Portal suggested that he and Cockcroft interview Fuchs to get him to confess. He wanted to pledge to Fuchs that if he confessed, “no legal or repressive action would be taken against him for his activities in New York.” Dick White quickly pointed out a number of problems with the suggestion and gently reestablished the responsibility for the interrogation within MI5. The question of what was to become of Fuchs was deferred once again until after Skardon’s next round with Fuchs.
That afternoon the MI5 group reviewed the morning’s discussion. Their first concern was to maintain Fuchs’s impression that MI5 would not inform the Ministry of Supply about the espionage allegations. Their second was to disabuse Portal firmly about interrogating Fuchs. They spun a rationale to offer Portal: he had to disassociate himself so he couldn’t be questioned by Parliament or the press about the source material. He needed to maintain deniability.
Another problem, quietly brewing, brought the meeting to an end with a tense discussion. The decoders in Arlington had just identified a Venona message that referred to a trip Goose, Rest’s handler, made to Rest’s sister in Cambridge, Massachusetts, on September 20, 1944. Because of a corrupt number group, it wasn’t clear if a certain sentence referred to Rest’s departure on that date or his sister’s. If it was Rest’s, Fuchs’s movements did not fit the timeline in the messages. He was already in Los Alamos then. Liddell reflected in his diary, “It is evident we are on somewhat shifting sand, and that it is never possible to be certain that we have got the correct solution unless we have all the groups in the sentence. This is rather disturbing.”
In the midst of his uncertainty, Skardon’s second interrogation of Fuchs took place on December 30.