World

The divided life of Bruno Pontecorvo—physicist or spy

An extract from a new tale of spooks and scientists

March 13, 2015
Bruno Pontecorvo, right, with his fellow physicist Carlo Franzinetti
Bruno Pontecorvo, right, with his fellow physicist Carlo Franzinetti
The following is an extract from "Half Life, the divided life of Bruno Pontecorvo" the new book by the Oxford University physicist Frank Close, published by Oneworld. Pontecorvo was a prodigiously gifted physicist who, before the Second World War, worked with Enrico Fermi on the phenomenon of "slow neutrons", work of fundamental significance in advancing the scientific understanding of matter. Pontecorvo went on to become an outstanding scientist in his own right, and during the war was at the heart of the Allied effort to harness nuclear energy. He worked on highly sensitive reactor projects in both Canada and Britain. After the war he settled in Britain, working at the Harwell nuclear research facility in Oxfordshire. Then in the summer of 1950, Pontecorvo and his family vanished.

Listen to Close discussing his book at a Prospect event:



“Did MI5 get back to you after I forwarded them your letter?”

The neat, handwritten note, on House of Lords stationery, was brief and to the point.When I received it, about two years into my research into the enigmatic life of physicist and possible spy, Bruno Pontecorvo, I had no idea that it would lead me to solve the mystery of his sudden disappearance at the height of the Cold War in 1950.

MI5 did get back to me: a file of “lost” papers regarding Pontecorvo had been “found.” The final entry in the MI5 record before Bruno Pontecorvo’s disappearance was a letter received on July 19, 1950, from the British embassy in Washington. The document, marked “SECRET,” appears to have had little impact. No action was taken in London. It would, however, lead to action in the Soviet Union. Once I saw the letter, the kaleidoscope of facts began to settle into a clearer picture.

***

In the years immediately after World War II, the British embassy in Washington, DC, was the weak point of Western security. Unknown to the authorities, it played host to three members of the infamous Cambridge Five spy ring. From 1944 to 1948, one of these spies, Donald MacLean, exploited his position as the British representative on the American-British-Canadian council on the sharing of atomic secrets. He was, of course, privy to these secrets, and passed news about development of the atomic bomb and nuclear power to the Soviets. Meanwhile, another member of the group, Guy Burgess, was based in the Foreign Office in London until late 1950. For a period in 1949 and 1950, Burgess forwarded to the KGB information that had originated with Kim Philby in Washington. This continued until Burgess too moved to the Washington embassy.

Kim Philby had arrived at the embassy in September 1949. He formal title was First Secretary but his specific (and covert) role was as a representative of the Secret Intelligence Service (SIS), or MI6 . Ever since World War II, the United Kingdom and the United States have shared intelligence. Thus, one of Philby’s duties was to liaise with the CIA, which meant that he was aware of some American operations, in addition to British ones.

In reality, Philby was a traitor throughout his career, from 1934 until his exposure in 1963.His autobiography admits that he was a double agent, who worked for the Soviet Union but was paid by the British. Philby himself wrote of his “total commitment to the Soviet Union.” He regarded his “SIS appointments purely [as] cover-jobs” to be carried out only well enough to enable his “service to the Soviet Union to be most effective.”His résumé of duplicity includes giving alerts to the Soviets when their atomic spies came under suspicion. Philby used his position to alert the Soviets about two confirmed spies: Alan Nunn May and Klaus Fuchs. It now seems that he tipped them off also about Bruno Pontecorvo, by far the most brilliant atomic physicist of the three.

Philby was one of a handful of people who were party to the biggest diplomatic secret in the postwar West: the VENONA project, an American program to intercept and decrypt Soviet intelligence traffic. In the summer of 1949, Meredith Gardner, a lean and gangly American linguist, cracked the Soviet diplomatic codes. Radio messages between Moscow and its Soviet embassies in North America were now open to the West. Philby was briefed about VENONA in September 1949, soon after the Soviets detonated their first atomic bomb. He immediately told the Soviets that their codes had been cracked, and took careful note of every decrypt that came to his attention.

The decrypts contained references to three scientists who had been working on the Manhattan Project. The message revealed that the trio, code-named CHARLZ, QUANTUM and MLAD, had passed atomic secrets to the Soviet Union. Philby learned that CHARLZ had been identified as Klaus Fuchs who, despite Philby’s best efforts, was arrested in February 1950 and imprisoned.

Philby was ultracareful. The Soviets’ intelligence operation at their embassy in Washington was in a turbulent state, two of their residents having been recalled to the USSR in the months prior to Philby’s arrival in the city. He therefore refused to deal with any Soviet intelligence officers in the US, and for about a year his only contact with Moscow headquarters was via messages sent through his co-conspirator Guy Burgess in London.

The pace of events quickened after Fuchs was arrested. In June 1950, Philby learned of a new breakthrough in the VENONA decryptions: Soviet telegrams from 1945 had revealed the existence of a ring of spies at the heart of British intelligence. However, the information from VENONA was fragmentary. At this stage, they had only partial decrypts. This was just as well for Philby, who immediately understood that this information referred to himself and his colleagues in the Cambridge Five.

In order to keep abreast of developments, Philby maneuvered to increase his access to VENONA, and arranged for SIS to provide him immediately with copies of any new VENONA material. The official reason for this arrangement, as stated in a letter sent to the director general of SIS on July 18, 1950, by Geoffrey Patterson, the Washington embassy’s liaison with US security, was that it would enable Philby to absorb and analyze new information before he met with the FBI. In reality, of course, Philby was simply trying to protect himself. As a result of these maneuvers, Philby learned that VENONA had identified a code name, HOMER, which he recognized as referring to MacLean. This information was passed on to Moscow. The following year, as the net closed, MacLean—along with Burgess, who had also been compromised—would defect to the USSR.

Tim Marten worked in the British embassy in Washington at this time, and one of his responsibilities involved communications on atomic energy. Tim recalled how these messages “were ultra-secretand therefore went through the MI6 communication channel. So Philby, as head of MI6 in Washington, had direct access to every telegram that I sent or received.” At this memory, Tim gave an ironic laugh. He then continued: “But of course I thought Philby was rather a good egg at the time. He appeared to be quite a wheel, in constant touch with the CIA and State Department. He was a very highly regarded person all round and obviously very competent. What we didn’t know at that moment was that he was passing everything on to the Russians.”

Philby’s unique access to American and British intelligence enabled him to conduct the espionage orchestra during the critical months of 1950, when the Soviet networks in North America were in danger. In addition to information that affected him directly, or references to the Cambridge spy ring, he kept a careful watch for anything that would interest his real employer, the Soviet Union. In the middle of July, he saw another letter that Patterson had drafted.

Written on July 13, 1950, and received by the director general of MI5in London on July 19 (and most probably by Philby’s contacts in Moscow soon after), Patterson’s letter concerned Bruno Pontecorvo: “The FBI informme that it has been reported to them that PONTECORVO is at present employed by AERE at Harwell. They add that they addressed communications dated February 2nd, 10th and 19th, 1943 to British Intelligence on the subject of PONTECORVO. Presumably they must have written either direct to London or to BSC New York because the local SIS representative cannot trace the correspondence. Many of the BSC files were destroyed [at the end of the War].”

Patterson then pointed out that Pontecorvo had worked on the Anglo-Canadian atomic energy project during the war, and had also lived in the United States. “The [FBI] now ask if we can send them any information which may be available to us which would indicate that PONTECORVO may be engaged in Communist activities at the present time or may have been engaged in such activities during his residence in the United States.”

Patterson’s letter, which explicitly mentions the “local SIS representative” in Washington, shows that Philby, the overall SIS chief in Washington, was fully aware of these developments. As he had done with Alan Nunn May, and then Klaus Fuchs, he now had to tell Moscow of the West’s interest in another atomic scientist: Bruno Pontecorvo.

As stated by Patterson, the British intelligence team in Washington was unable to locate the 1943 letters from the FBI, even when the letters’ existence was brought to their attention. Given Philby’s reputation, one might imagine that the failure to find the letters occurred because he had destroyed the evidence. However, it seems more likely that, on this occasion, Philby was acting in good faith:the 1943 correspondence was indeed lost, possibly when the British Security Coordination closed at the end of World War II and many files were destroyed.

The FBI subsequently forwarded copies of the letters to MI5. They showed evidence only of Bruno’s communist associations. They did not show evidence that he was a spy. Their resurrection in July 1950 suggests that they were part of a fishing expedition conducted by the Americans, inspired by McCarthyism. If Philby had seen these letters, they would have raised little alarm. However, it seems he did not. All he knew was that the FBI was interested in an atomic scientist named Bruno Pontecorvo, that they had written not just one but three letters about him within seventeen days in 1943, and that VENONA had revealed the existence of two still-unidentified spies at the heart of the atomic project, code-named MLAD and QUANTUM, one of whom might be Pontecorvo.

MLAD would eventually be identified as Ted Hall, a brilliant young physicist who was arguably the most successful of the “atom spies.” QUANTUM remained an enigma until 2009, when KGB files identified him as Boris Podolsky, a US-born Russian physicist. None of this was known to Philby in 1950. We have no hard evidence that Philby warned Moscow about the FBI’s interest in Pontecorvo, or what the warning might have consisted of, but it is most improbable that a warning was not transmitted.

Today it seems probable that the letter from Washington was a key—perhaps the key—to Bruno Pontecorvo’s unpremeditated flight.

***

MI5 completed its initial inquiry into Pontecorvo’s disappearance by December 1950, three months after his defection. At the time, the British were oblivious to Philby’s duplicity, so no one suspected that the FBI’s interest in Pontecorvo was known in Moscow. Although the British government feared that Pontecorvo had fled because he had previously passed classified information to the Soviets, MI5 had no sure evidence, and its investigations led to no certain conclusions. So what can we conclude today about of the case of Bruno Maximovitch Pontecorvo and his possible role as a spy?

As a physicist myself, I am drawn to a scientific analogy. It was once believed that the earth was at the centre of the solar system. To explain the planetary orbits required a large number of “epicycles,” special refinements added to the model as better data arrived from astronomers. The theory soon became unwieldy. With the single assumption that the planets orbit the sun, however, everything suddenly fits. I take a similar view about the Pontecorvo affair. If one concludes, based on the absence of evidence against him, that he had no dealings with the Soviets when he was in the West, then several independent theses are required to explain various unresolved questions. On the other hand, if one accepts the hypothesis that Pontecorvo passed secrets before 1950, the kaleidoscope of facts settles into place.

Here is a sample.

Near the end of 1949, blueprints of the Canadian reactor arrived in the USSR.

The source was someone other than Nunn May, who had been jailed in 1946. It is possible that the Soviets convinced Pontecorvo to hand over the blueprints before his defection, to aid their goal of building a nuclear reactor for the social and economic welfare of their citizens. It would have appeared churlish if Bruno, member of the Communist party, refused such a request to help an ally.

The KGB courier, Lona Cohen, made visits to the US-Canadian border on various occasions between 1944 and 1948, in order to exchange information with someone based in Canada. Bruno Pontecorvo likewise travelled from Montreal to the US border regularly, ostensibly to keep his application for US citizenship active. A sample of uranium made its way from Canada to the USSR, and Lona Cohen was its courier.

This was additional to a sample that had earlier come from Alan Nunn May. Whereas Nunn May’s source of uranium was the American reactor, the second sample almost certainly came from Canada itself, which was only possible after the main reactor began operating in 1947. The previous year, Bruno had turned down job offers from various prestigious US universities in order to go to Harwell, and then dithered, changed the starting date, and suddenly decided to remain in Canada to work on their reactor. This behaviour could of course reflect genuine indecision, but it also fits rather conveniently with a portrait of a man required to keep the Soviets abreast of developments in the reactor field.

Geoffrey Patterson sent his letter from Washington, which Philby intercepted, in July 1950, a few days before the family left England prior to Pontecorvo’s flight.

The fact that Bruno made a precipitate decision to flee, rather than planning a more orderly move to the Soviet Union, suggests that he was reacting to a major crisis, rather than moving for personal reasons as a matter of principle. The exfiltration of Lona Cohen to the USSR in July 1950, only weeks before Pontecorvo’s arrival, is another intriguing coincidence.

The Soviet reactions to his arrival, which included interrogation and five years under guard, are hardly an appropriate welcome for a hero of socialism.

The Soviets’ treatment of Pontecorvo upon his arrival in the USSR suggests that they didn’t trust him. This is perhaps understandable, whatever the reasons for his defection. However, this supposed mistrust fits uneasily with the commitment the Soviets had invested in getting him there, and Pontecorvo’s precipitate agreement to go along with the plan. The total picture fits more naturally with the idea that the Soviets were punishing Pontecorvo—that Pontecorvo had been an agent who was “trying to disengage” or become independent. He certainly wasn’t treated like a hero who had voluntarily chosen to come to the USSR in protest against Western ways.

***

In October 1992, a Russian historian was doing research for a documentary about the Cold War, on behalf of the American television network ABC.

During a conversation between the researcher and their KGB guide, the possibility of interviewing Bruno Pontecorvo came up. The KGB host duly asked Pontecorvo for an interview “just for the record,” but Pontecorvo robustly declined. The researcher did not speak to Pontecorvo personally, but his response, as related by the KGB contact, “rung in my ears”: “ Ya khochu umeret’ kak velikii fizik, a ne kak vash jebanyi shpion.

“I want to die as a great scientist, not as your fucking spy.”