Although there are imagined conspiracies, there are also real conspiracies, and Soviet atomic spying belongs to the second category. There was a largescale espionage apparatus reaching into at least three countries—the United States, Great Britain, and Canada—during the Cold War. Historians of the 1960s and 1970s tended to dismiss the accusations of spying as products of popular paranoia during the McCarthy witch-hunts of the 1950s.
More recently, however, with the release of formerly unavailable U.S. intelligence documents and files from the Soviet Union, some historians and commentators have begun to reassess the accusations of atomic spying, arguing that the case has finally been proven; others remain convinced that the original charges were exaggerated or fabricated.
The beginning of the story dates back to late 1940, when Leonid Kvasnikov of the scientific and intelligence section of the NKVD (the Communist secret police) noted a flurry of publications in Western scientific journals dealing with atomic energy following the German chemist Otto Hahn’s successful splitting of the uranium atom. Kvasnikov instructed NKVD agents abroad to keep a watch for developments in that area.
The most important response came in September 1941—most likely from John Cairncross, then private secretary to the British government’s top scientific adviser and one of the “Cambridge Five” recruited as Soviet spies in the 1930s—telling of British plans to develop an atomic bomb. Further details about these plans were supplied by a German Communist émigré scientist working in Britain named Klaus Fuchs. The upshot was that Kvasnikov was sent to New York at the end of 1942 to head up atomic spying in the United States.
Lax (or worse) British security procedures that failed to follow up reports about Fuchs’s Communist ties allowed him to be transferred to the Manhattan Project’s atom bomb building program at Los Alamos in New Mexico.
Fuchs was probably the most important source supplying the Soviets information about how to overcome the technical problems of producing the plutonium bomb. Although he provided data about the proposed hydrogen bomb, his contribution to the Soviets in that area was not as significant.
Fuchs was not the only Soviet spy at Los Alamos, but U.S. security officials made the mistake of dealing quietly via dismissal or transfer with those suspected of passing on information. The public at large remained ignorant of the problem until the defection in September 1945 of Igor Gouzenko, a code clerk at the Soviet embassy in Ottawa, Canada.
The data turned over by Gouzenko revealed a Soviet espionage network headed by the two top leaders of the Canadian Communist Party that included Alan Nunn May, a British physicist working for the Canadian atomic research program.
Despite the Gouzenko revelations, the search for atomic spies did not move into high gear until after the explosion of the first Soviet atomic bomb in August 1949. U.S. investigators focused their attention on Fuchs, who had by this time returned to Britain.
Under questioning, Fuchs confessed in early 1950 to his own spying—but with one exception refused to name others involved. And even regarding that one exception—his contact in the United States, Harry Gold—Fuchs did not take the initiative but simply confirmed his identity after Gold had become suspect from other sources.
The reputation of British counterintelligence was further tarnished when the Italian-born physicist Bruno Pontecorvo and his wife defected to the Soviets in August-September 1950. An even more devastating blow was the flight behind the Iron Curtain in May 1951 of two of the “Cambridge Five”—diplomats Donald Maclean and Guy Burgess. Maclean was the bigger Soviet prize because he had been the representative of the British embassy in Washington, D.C., dealing with the political aspects of atomic energy.
By this time, the major focus of action had shifted to the United States, with the arrest on 23 May 1950 of Harry Gold. Gold’s confession implicated David Greenglass, who had worked as a mechanic at Los Alamos, and his wife Ruth. They implicated David’s sister, Ethel Rosenberg, and her husband Julius. The trial and execution (19 June 1953) of the Rosenbergs remains controversial because of complaints about the bias of the presiding judge, prejudicial actions by the prosecution, and the excessiveness of the penalty.
Many on the Left have argued (and continue to argue) that the Rosenbergs were the victims of a deliberate government conspiracy to frame them (or, in a lesser charge, that the government succumbed to the public hysteria in pushing for the death penalty), but in the eyes of most historians there now remains no question about Julius Rosenberg’s guilt. More doubtful is how active a role had been played by his wife.
She appears to have been included in the prosecution as a lever to pressure Rosenberg into naming others, and the Greenglasses—who were the government’s major witnesses—changed their testimony about her involvement only on the eve of the trial. On the other hand, Julius could have saved his life and hers by cooperating with the government had he not put his loyalty to the Stalinist regime first.
An even more valuable Soviet informant was Theodore A. (Ted) Hall, who had come to Los Alamos in 1944 as a nineteen-year-old scientific prodigy. At least as Hall would later tell the story, he had not been recruited, but had approached the Soviets on his own initiative because he felt that a United States monopoly of the atomic bomb would be a threat to the world.
Although Hall came under suspicion, the Federal Bureau of Investigation lacked sufficient hard evidence for an arrest before he and his wife left for Britain. There he built a successful career as a scientist. His definitive exposure would not come until the 1990s.
The one major actor accused of spying whose guilt remains open to question is J. Robert Oppenheimer, who had headed the Los Alamos project. Oppenheimer’s opposition to building the hydrogen bomb reinforced suspicions about his loyalty growing out of his close personal ties with Communists and fellows travelers.
Hearings in 1954 resulted in the revocation of his security clearance. Although Oppenheimer’s defenders charge that he was the victim of a baseless witch-hunt, new evidence shows that at a minimum, he had been guilty of failing to inform security officials fully about Soviet infiltration efforts of which he had knowledge.
One of the difficulties in countering Soviet atomic espionage was that the culprits were ideologically motivated rather than spies-for-hire. Thus, few would cooperate even when caught and even fewer would express any regret.
Although Fuchs pretended to do so, he left for East Germany after his release, announced that he was still a loyal Marxist, and went on to become director of the East German Central Institute for Nuclear Physics.
Estimates of the contribution made by espionage to speeding up the building of the Soviet atomic bomb range from a minimum of eighteen months to a maximum of five years. And except for the Rosenbergs none of the guilty suffered punishment commensurate with the enormity of their crimes.
Even those imprisoned—such as May, Fuchs, David Greenglass, and Gold—served no more than part of their sentences before release. Ruth Greenglass avoided prosecution because of a deal struck by her husband in return for his testimony.
At least two of Julius Rosenberg’s accomplices—Joel Barr and Alfred Sarant—fled the country and successfully disappeared. None of the “Cambridge Five” spent a day of prison time. Worst, Anatoly Yatskov, Kvasnikov’s successor as top Soviet atomic spy master in the United States, would boast that at most half of his spy network had been uncovered.