The Soviets vigorously courted Oppenheimer but he refused to spy for them

The Soviets did manage to plant spies who provided the secrets of the atomic bomb to the Kremlin and allowed them to detonate the first bomb in August 1949, it was a copy of the bomb built in Los Alamos and dropped by the Americans on Nagasaki. British intelligence acquitted Oppenheimer

Author: Calder Walton, Senior Research Fellow and Director of the Applied History and Intelligence Program at Harvard University's Kennedy School

"Oppenheimer", the new epic film directed by Christopher Nolan, takes viewers into the mind and moral decisions of J. Robert Oppenheimer, leader of the team of brilliant scientists in Los Alamos, New Mexico, who built the world's first atomic bomb. It's not a documentary, but it manages to tell the big historical moments and issues correctly.

The issues Nolan describes are not relics of the distant past. The new world Oppenheimer helped create, and the nuclear nightmare he feared, still exists today.

Russian President Vladimir Putin is threatening to use nuclear weapons in his war in Ukraine. Iran is doing everything it can to develop nuclear weapons. China is expanding its nuclear arsenal. Hostile governments like China are stealing American defense technologies, including from Los Alamos.

The claims that Oppenheimer was a Soviet spy and a security risk - a central focus of the film - have been refuted. In December 2022, the Biden administration posthumously reversed the US Atomic Energy Commission's 1954 decision to deny Oppenheimer's security clearance, calling the process biased and unfair. Declassified records released reveal that Soviet spying on the United States' atomic bombing effort advanced Moscow's bomb program, but Oppenheimer was not a spy.

The Oppenheimer perspective

Oppenheimer joined the Manhattan Project, a nationwide effort to build an atomic bomb before the Nazis developed one, in 1942. The scientists he led at the Los Alamos site were probably the most brilliant group of minds ever assembled in one laboratory, including 12 future Nobel Prize winners.

In 1954, at the height of the McCarthy era, Oppenheimer was accused of being a communist and even a Soviet spy. What is the truth?

We know that in the 30s, and until 1943, Oppenheimer was a communist activist. His brother Frank and his girlfriend Jean Tetlock were members of the Communist Party of the United States, and his wife Catherine was a former member.

For Opie, as his students called him, Marxism was intellectually interesting, but also practical. Oppenheimer saw communism as the best defense against the rise of fascism in Europe, which was personal to him, being Jewish.

By 1943, however, Oppenheimer's support for communist causes had changed—apparently, when he realized the enormity of his mission to produce an atomic bomb. That same year, Oppenheimer helped U.S. Army security officers identify scientists he believed to be communists.

Russian courtship

Oppenheimer was a primary target of Soviet intelligence, who gave him the secret nicknames CHESTER and CHEMIST. Soviet intelligence officers also tried to recruit him. But being a target and being courted for recruitment is not the same as being a recruiting spy.

As the film shows, in 1943 Oppenheimer's academic colleague at the University of California at Berkeley, Hakon Chevalier, told Oppenheimer that a British scientist working in San Francisco could pass information to the Soviets. Oppenheimer rejected that approach, but for reasons that remain unclear, he wouldn't let authorities know for several months.

Over the next several years, Oppenheimer provided at least three versions of the story, sometimes including his brother Frank. It seems that Robert was trying to protect his brother from the military security.

Archives published after the collapse of the Soviet Union today confirm beyond any doubt that Oppenheimer was not a Soviet agent. In fact, Soviet intelligence reports on the Manhattan Project reveal that at key points, Soviet spy chiefs were frustrated that their agents did not recruit Oppenheimer. But the Russians infiltrated the Manhattan Project - the biggest security breach in US history.

All the people of the Kremlin

Many scientists who worked on the Manhattan Project provided critical information about US atomic bomb research to the Soviet Union.

"Oppenheimer" focuses on Klaus Fuchs, a brilliant theoretical physicist who escaped from Nazi Germany to Britain and became a British citizen in Montreal. Since he began working on the British wartime atomic bomb project, Fox said he was in "continuous contact" with Soviet intelligence, providing theoretical calculations that were necessary for building an atomic bomb.

General Leslie Groves, the military commander of the Manhattan Project, later blamed the British for not recognizing Fox as a Soviet spy. That's the fact. But the classified file on Fox from the British security service MI5 shows that at the time, the agency had no positive and reliable evidence of Fox's communism. MI5 knew that Fox was anti-Nazi, but not that he was pro-Soviet.

Other spies at Los Alamos included a gifted scientist, Theodore "Ted" Hall (code name MLAD, "Young"); Julius Rosenberg (code name ANTENNA, later LIBERAL); David Greenglass (BUMBLEBEE, CALIBER). Other Soviet spies, such as British scientist Alan Nan May, worked in other parts of the Manhattan Project.

These people had multiple motives to betray US atomic secrets. They were true communist believers and thought that nuclear weapons were too powerful to be possessed by just one country. In addition, they had a (false) defense - that the Soviet Union was America's wartime ally, so they only gave secrets to an allied government. But as Nolan correctly shows in the film, when Chevalier told Oppenheimer that a British scientist working in San Francisco might pass information to the Soviets. Oppenheimer rejected the approach, but as I said before, he did not inform the authorities about this for several months, and the reason for this is not clear.

By the end of World War II, Stalin's spies provided the secrets of the atomic bomb to the Kremlin. It saved the Moscow bomb project. When the Soviets detonated their first atomic weapon in August 1949, it was a replica of the bomb built at Los Alamos and dropped by the Americans on Nagasaki.

Even now, almost 80 years later, new secrets about Soviet nuclear espionage are still being discovered. One Soviet agent who has only recently been discovered is George Koval (code name DEVAL), an American engineer recruited into the Manhattan Project, where he worked on polonium bomb "lighters" at a facility in Dayton, Ohio.

After Koval's death in 2006, at the age of 93, the Russian Ministry of Defense revealed that the first "ignitor" for the Soviet atomic bomb was prepared according to specifications provided by Koval. Putin awarded Koval after his death the "Hero of Russia" decoration, and raised a glass of champagne in his honor.

New goals

If Nolan's film makes audiences interested in reading Kai Byrd and Martin Sherwin's in-depth research biography of Oppenheimer, which served Nolan to make this film, or other accounts of the Manhattan Project or the Cold War, they will find that the underlying tissues of science and espionage remain alive.

Today, the world is on the brink of technological revolutions that will change societies in the 21st century, similar to how nuclear weapons changed the 20th century: artificial intelligence, quantum computing and biological engineering. Watching "Oppenheimer" makes me wonder if hostile foreign governments may have already stolen keys to hack these new technologies, the same way the Soviets did with the atomic bomb.

For an article in The Conversation

More of the topic in Hayadan:

• Spies in Los Alamos
• The Jews, the Nazis and the race for the atomic bomb
• Researchers at Los Alamos Laboratories: We've been able to figure out how to blow up an asteroid that threatens Earth
• Nuclear ghosts