Even while joining forces with the United States and Great Britain against Nazi Germany during World War II, the Soviet Union launched a massive effort to gather intelligence on the Anglo-American secret atomic bomb program which would become the Manhattan Project.
As part of Operation Enormoz (“huge”), Soviet agents recruited American and British spies who were committed Communists, including several scientists from the Los Alamos laboratory. The extent of Soviet nuclear espionage was unknown until after the war, when the United States and Britain successfully cracked the code used in Soviet telegraphs. Because the decryption project, known as Venona, remained confidential until 1995, evidence of it could not be used in court, allowing many suspected spies to evade prosecution. .
WATCH: The Great Spy Stories of the 20th Century on HISTORY Vault
John Cairncross
John Cairncross, British scholar, Soviet atomic official and spy, is pictured in his home October 18, 1990 in Saint-Antonin, France.
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Cairncross worked as the private secretary to Sir Maurice Hankey, a senior British official involved in Tube Alloys, Britain’s secret atomic program during World War II. In this post, he gave Moscow a list of American atom scientists and may have leaked information about a report assessing Britain’s prospects of building a uranium bomb in 1941. After having Interviewed by MI5 in the 1960s and confessed to being a Soviet spy, Cairncross gave information in exchange for immunity from prosecution. In 1990, he was finally identified as the “fifth man” of the infamous group of spies (also including Kim Philby, Guy Burgess, Donald Maclean and Anthony Blunt) who met at Cambridge University in the years 1930. Cairncross died on October 8, 1995 in Herefordshire, England.
Melita Norwood
Melita Norwood, 87, stands outside her home in Bexleyheath, England, in 1999 to read a statement regarding her involvement in passing atomic secrets to the KGB.
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The Soviet Union’s longest-serving spy in Britain, Norwood worked as a secretary for a director of the Tube Alloys project. While leading a seemingly normal life in the London suburbs, she passed information on to Soviet agents throughout the war and into the 1970s. It is not known how much Norwood’s espionage aided the Soviet atomic program, but she was officially honored for her work when she visited Moscow in 1979. Eventually exposed as a spy in the 1990s, Norwood “happily admitted what she had done and said she would do it. again, ”says Harvey Klehr, Emeritus Professor of Politics and History at Emory University and author of various books on Soviet espionage.
Klaus Fuchs
Police photo of physicist-turned-spy Klaus Fuchs. (Credit: public domain)
Fuchs, a German-born physicist, fled to England amid the rise of Nazism in 1933 and became a British citizen in 1942. By this time, he had already offered to spy for the Soviets. At the end of 1943, Fuchs joined a group of British scientists who traveled to Los Alamos to work for the Manhattan Project, and he then passed on to the Soviets key information on the design of atomic weapons that enabled them to ” speed up their nuclear program. After deciphered cables revealed Fuchs’ spying, he confessed in the early 1950s. His testimony led authorities to Harry Gold, an important courier for other Los Alamos spies.
David Greenglass
David Greenglass, sergeant and machinist assigned to the Manhattan Project, pictured in 1950. Green glass passed data on the making of atomic bombs to his sister, Ethel Rosenberg.
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Gold in turn named David Greenglass, a US Army machinist who had worked at the classified nuclear facility in Oak Ridge, Tennessee before being posted to Los Alamos in 1944. Recruited to spy for the Soviets by his beau -Brother, Julius Rosenberg, Greenglass passed information to the Soviets in mid-1945, which included a hand-drawn sketch and notes describing the imploding bomb. In his 1950 confession, Greenglass implicated his own sister, Ethel Rosenberg, who he said typed the notes sent to the Soviets. His cooperation earned him less punishment and immunity for his own wife, Ruth. Based largely on the testimony of the Greenglass, the Rosenbergs were convicted and executed in June 1953.
Russell mcnutt
McNutt was a civil engineer in New York and a friend of Julius Rosenberg, who encouraged him in late 1943 to find employment with Kellex, a company that was building the massive gas diffusion plant to separate uranium at Oak Ridge. . Rosenberg linked McNutt to the KGB, the Soviet security agency. Although he gave the Soviets the design of the factory, McNutt (despite Soviet calls) refused Kellex’s offer to move from New York to Oak Ridge, where he would have had access to more scientific data.
“The FBI interrogated him because he was friends with Rosenberg, but they never suspected him of being a spy,” Klehr says. After the war, McNutt worked for Gulf Oil and headed the company’s Gulf-Reston division, which built the planned community in Reston, Virginia, right next to the CIA headquarters in Langley. McNutt’s spying was later revealed in the notebooks of Alexander Vassiliev, a journalist and former KGB officer who was able to take notes on sensitive KGB archives dating from 1930-50.
Clarence hiskey
Former professor of physics and atomic scientist Clarence Hiskey (left) appears in Brooklyn federal court on November 11, 1950.
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Hiskey, a chemist, began working on gas diffusion at Columbia University and was later transferred to the Chicago Metallurgical Laboratory (Met Lab), another key part of the Manhattan Project. Hiskey passed information to the GRU, or Soviet military intelligence, rather than the KGB. After being seen meeting with known Soviet agent Arthur Adams in 1944, U.S. Army intelligence officials enlisted Hiskey on active duty (he had a reserve commission) and sent him to Alaska.
“They didn’t want him arrested because if they were to charge him it would reveal the fact that he was working on this top secret project,” Klehr says. Hiskey was called to testify before a Congressional committee after the war, but declined to answer questions about his alleged espionage. “They really didn’t have any hard evidence,” Klehr points out. “So he got away with it.” Hiskey then taught chemistry at Brooklyn Polytechnic Institute and worked in several biotechnology companies.
Théodore room
Photo of Los Alamos National Laboratory’s Theodore Hall ID badge.
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The publication of the decrypted Venona interceptions in the mid-1990s revealed that Theodore Hall, the youngest Manhattan Project physicist, was the third long-suspected spy (after Fuchs and Greengrass) in Los Alamos. Codenamed “Mlad”, Hall had contacted the Soviets in late 1944 and shortly after provided them with a key update on the development of the plutonium bomb. The FBI first learned of Hall’s espionage activities in the early 1950s, but without a confession, the FBI had to let him go rather than reveal Project Venona to the Soviets. Hall then moved to Britain, where he became a pioneer in biological research.
Oscar Seborer
In 2019, after searching the recently declassified FBI files, Klehr and John Earl Haynes reported the existence of a fourth Soviet spy in Los Alamos. Oscar Seborer, nicknamed “Godsend”, was the son of Jewish immigrants from Poland who became an electrical engineer and worked in Los Alamos from 1944 to 1946. Although it is still unclear exactly what information Seborer provided to the Soviets, his work on wiring the bomb’s explosive trigger would have given him access to information different from that of Fuchs and Hall, including key information about the method of implosion detonation.
“At this point, we don’t know exactly what he delivered,” says Klehr. “It could have been very important, that’s about all we can say.” By the time the FBI learned about Seborer’s spying in the mid-1950s, he had left the United States and moved to Russia, where he lived until his death in 2015.
