Perspective: Atomic spiesFourth Spy Unearthed in U.S. Atomic Bomb Project

Published 25 November 2019

The United States detonated world’s first atomic bomb on 16 July 1945. Four years later, in August 1949, the Soviet Union detonated a nearly identical device in Central Asia – an event which stunned the U.S. military and scientific communities, which did not believe the Soviet Union had the scientific and technical know-how to do so. By 1950s, it became clear that the Soviet quick march to the bomb was aided by spies that the USSR managed to place in Los Alamos – three of them were identified early on. The identity of the fourth has just been revealed.

The United States detonated world’s first atomic bomb on 16 July 1945. Four years later, in August 1949, the Soviet Union detonated a nearly identical device in Central Asia – an event which stunned the U.S. military and scientific communities, which did not believe the Soviet Union had the scientific and technical know-how to do so.

William J. Broad writes in the New York Times that by 1950s, it became clear that the Soviet quick march to the bomb was aided by spies which the GRU, the Soviet intelligence service, managed to place in Los Alamos – and two of the major spies were quickly identified: Klaus Fuchs and David Greenglass. The identity of the third spy, Theodore Hall, was not publicly disclosed until 1995. Hall, who moved to England in 1962, was never convicted of espionage.

Two historians, Harvey Klehr and John Earl Haynes, have just published a study in of Studies in Intelligence, the C.I.A.’s in-house journal, which completes the atomic espionage puzzle. In their article, titled “On the Trail of a Fourth Soviet Spy at Los Alamos,” the two identify the fourth Soviet atomic spy: Oscar Seborer.

Broad writes:

From an examination of archival materials from the K.G.B., the Soviet Union’s main intelligence agency, Mr. Klehr and Mr. Haynes learned about a shadowy group of moles in the United States known as the “Relative’s Group.” Three of the faction’s members — code-named Relative, Godfather and Godsend — were brothers. According to the study, the archival documents said that Godsend was at Los Alamos and that he was providing secret information on “Enormous,” the K.G.B.’s code name for the American project.

In 2012, Mr. Klehr obtained newly declassified F.B.I. files on informants who had successfully penetrated the Communist Party of the United States. Suddenly, he started seeing references to the Seborers, and major parts of the atomic puzzle fell into place: Oscar was Godsend, Stuart was Godfather and their older brother Max was Relative.

Seborer fled the United States to the Soviet Union in 1951, accompanied by his older brother Stuart, as well as his brother’s wife and mother-in-law. In 1964 he received the Order of the Red Star, a prestigious military award. He died in Moscow in April 2015