An Atomic Spy; Recently Declassified Documents “Potentially Recast A Mundane Espionage Case As One Of History’s Most Damaging;” The Identify Of The Fourth U.S. Los Alamos Nuclear Spy Finally Revealed After Seven Decades

An Atomic Spy; Recently Declassified Documents “Potentially Recast A Mundane Espionage Case As One Of History’s Most Damaging;” The Identify Of The Fourth U.S. Los Alamos Nuclear Spy Finally Revealed After Seven Decades
       The title above comes from William J. Broad’s January 28, 2020 feature article in the Science Times section of the New York Times. He writes that “last fall, a pair of historians revealed yet another Soviet-spy, code-named Godsend, had infiltrated the Los Alamos National Laboratory where the world’s first atom bomb was built. But, they were unable to discover the secrets he gave Moscow, or the nature of his work.” Recently declassified documents “detail the spy’s highly specialized employment and likely atomic thefts, potentially recasting a mundane espionage case as one of history’s most damging,” Mr. Broad noted. I refer you to the January 28, 2020 edition of the New York Times for Mr. Broad’s full article.
      “It turns out that the spy, whose real name was Oscar Seborer, had an intimate understanding of the bomb’s inner workings,” Mr. Broad wrote. “His knowledge likely surpassed that of the three previously known Soviet spies at Los Alamos, and played a crucial role in Moscow’s ability to quickly replicate the complex device,” Mr. Broad added. “In 1949, four years after America tested the bomb, the Soviets detonated a knockoff, abruptly ending Washington’s monopoly on nuclear weapons.”
     “It’s fascinating,” said Harvey Klehr, an author of the original paper in an interview. “We had no idea he was that important.”
     “The documents from Los Alamos show that Mr. Seborer helped devise the bomb’s explosive trigger — in particular, the firing circuits for its detonators,” Mr. Broad noted. “The successful development of the daunting technology let Los Alamos significantly reduce the amount of costly fule needed for atomic bombs, and began a long trend of weapon miniaturization. The technology dominated the nuclear age, especially the design of small, lightweight missile warheads of enormous power.” Glen McDuff, a Los Alamos scientist, once characterized the bomb’s firing device as “unbeliveably compicated,” Mr. Broad wrote.
     “Mr. Seborer’s inner knowledge stands in contrast to the known espionage,” Mr. Broad wrote. “The first Los Alamos spy gave the Soviets a bomb overview. So did the second and the third.”
     “The new clues suggest that Mr. Seborer’s thievey “could have been unique,” Alex Wellerstein, a nuclear historian at the Stevens Institute of Technology in Hoboken, N.J. said in an interview. “That doesn’t mean it was — just that it could have been.”
     Mr. Seborer defected to the Soviet Union in 1951, along with his older brother Stuart, his brother’s wife, and his mother-in-law, Mr. Broad noted. A communist acquaintance visited the brothers and said that the two brothers claimed they could never return to the United States because they would likely be executed. Of note, Julius and Ethel Rosenberg were executed on June 19, 1953 for sumuggling atomic secrets to the Soviet Union.
     “Possible clues of Mr. Seborer’s espionage lurk in declassified Rissian archieves,” Mr. Broad wrote. Mr. Wellerstein said that the documents show that Soviet scientists “spent a lot of time looking into the detonator-circuity issue,” and include a diagram that appears to have derived from spying.” Mr. Broad explains that “the diagram shows an implosion bomb. Several lables of the shcematic appear first in English, then Russian.” In a 2012 analysis, Mr. Wellerstein described the order as “betraying their obvious roots in espionage.” “The English lables include “Power Supply” and “Firing Unit.”  “In a follow-up analysis, Mr. Wellerstein concluded that Igor Kurchatov, the head of the Soviet bomb project, drew the schematic for Lavrenty Beria, the head of Stalin’s secret police,” Mr. Broad wrote.
     “The Soiviet diagram was dated June, 1946, four months after Mr. Seborer left Los Alamos,” Mr. Broad noted. “It shows pairs of wires running from an electrical controller to detonators on the bomb’s exterior — a clear echo of the American reliance on redundant firing circuits.”
     “I don’t know if any other of the known spies would have access, to the kind of secrets that Mr. Seborer worked on routinely at Los Alamos,” Mr. Wellerstein said. “The Americans spying for Moscow, might have filled the gap,” he added.
     The identiy of the fourth Los Alamos spy to betray U.S. nuclear secrets to the Soviet Union in the 1950s is now known; and, as Mr. Wellerstein wrote, is perhaps the most consequential of the foursome. Acquiring the intircate details of the trigger mechanism was a huge coup for the Soviets and allowed Moscow to leap-frog its way into the nuclear age. No wonder his code-name was…..Godsend.
     According to, “the FBI has known since 1955 that Oscar, his brother Stuart, Stuart’s wife Miriam, and Miriam’s mother, all secretly defected to the Soviet bloc in 1952, initially living in East Germany before moving to Moscow, where they lived under the name Smith. The brothers never returned from Moscow, but remarkably Miriam, then divorced by Stuart, returned to the United States with her son (born in East Germany) and her mother in 1969 at the height of the Cold War. But, the role of Oscar Seborer and his associates in Soviet espionage has been hidden for seven decades.” Oscar Seborer died in Moscow on April 23, 2015, added; and his brother Stuart attended in a wheelchair. Of note, a representative of the Russian FSB also attended the funeral.
     The fact that the entire family fled or was given sanctuary was, and still is, standard practice for intelligence agencies who successfully recruit a well-placed, valuable spy. Knowing at some point that the ‘gig will be up,’ the recruiting agency offers — if there is the opportunity, time, and abilty — to move the well-placed spy’s entire family out of harm’s way before they are discovered/arrested. Clearly, Mr. Seborer was a well-placed/valuable spy, a Godsend for the Soviet nuclear program, and perhaps Los Alamos’s most damaging traitor.  RCP,

Leave a Reply

Your email address will not be published. Required fields are marked *