U.S. Reverses 1954 Removal of J. Robert Oppenheimer’s Security Clearance

The “father of the atomic bomb” was accused of being a communist

J. Robert Oppenheimer in black and white in front of a chalkboard
J. Robert Oppenheimer led the Manhattan Project, a mission to develop nuclear weapons during World War II. Bettmann / Contributor via Getty Images

During the peak of the Cold War—when American fears of the Soviet Union were at a high—Senator Joseph McCarthy helped stoke a mass paranoia that communists were infiltrating life in the United States. The ensuing hysteria led the loyalties of hundreds to be scrutinized during the so-called Red Scare. One such person to come under fire was the famed physicist J. Robert Oppenheimer, the “father of the atomic bomb.”

Oppenheimer fell from grace after the Atomic Energy Commission (AEC) alleged he had ties to communism and revoked his security clearance in 1954. Now, almost 70 years later, the United States Department of Energy has reversed the decision, stating the trial was a “flawed process that violated the Commission’s own regulations.” 

“As time has passed, more evidence has come to light of the bias and unfairness of the process that Dr. Oppenheimer was subjected to, while the evidence of his loyalty and love of country have only been further affirmed,” Secretary of Energy Jennifer Granholm says in the statement.

What’s more, a review of the historical evidence shows the 1954 decision was less born out of genuine national security concerns than it was a product of the AEC’s disagreement with Oppenheimer on nuclear weapons policy, Granholm writes in the order. After World War II, Oppenheimer opposed nuclear proliferation and argued against developing the hydrogen bomb, writes Dan Whitcomb for Reuters.

Before the decision to revoke his clearance, Oppenheimer was widely regarded as a brilliant scientist. He graduated from Harvard in three years, researched at the University of Cambridge in England, earned a PhD at the University of Göttingen in Germany and became a professor at the University of California, Berkeley. 

One of his first contributions to the field of physics was for his work laying the “foundations of modern theory for the quantum behavior of molecules,” per his 1967 New York Times obituary. A few years later, he discovered the Oppenheimer-Phillips process, which “involves the break-up of deuterons [the nuclei of a hydrogen isotope called deuterium] in collisions that had been thought far too weak for such an effect,” per the Times. 

But he’s most well-known for his role in the Manhattan Project, a mission to develop the atomic bomb during World War II. Oppenheimer was then the director of the Los Alamos Laboratory. Described in his obituary as having a “special genius for administration,” he built a team of top-notch scientists and completed the mission in two years. The weaponry was then used to kill an estimated 200,000 people in the bombings of Hiroshima and Nagasaki, though the exact death toll is unknown. 

By the 1950s, suspicions of Oppenheimer were growing. The physicist had past associations with communists, including his brother, Frank, who briefly joined the party from 1937 to 1941. Oppenheimer was also outspoken against the development of the more powerful hydrogen bomb. 

In 1954, after a trial that lasted 19 days, the AEC declared Oppenheimer a risk to the United States, saying he had “‘fundamental defects’ in his character,” per the Associated Press. With his security clearance revoked, Oppenheimer was cut off from restricted information he needed to continue his work, and his career essentially came to an abrupt halt. 

Historians have long advocated for a reversal of the AEC's decision, writes the New York Times’ William J. Broad. In 2014, the Obama administration released declassified pages from the trial, and experts say they show no evidence of disloyalty or wrongdoing.

“I’m overwhelmed with emotion,” Kai Bird, co-author of American Prometheus, a Pulitzer Prize-winning biography of Oppenheimer, tells the Times. “History matters, and what was done to Oppenheimer in 1954 was a travesty, a black mark on the honor of the nation.”

Senator Patrick Leahy praised the reversal in a statement: “This decision reaffirms that government scientists, whether renowned like Oppenheimer or a technician doing his or her daily job—including those willing to raise safety concerns or to express unpopular opinions on matters of national security—can do so freely and that their cases will be fairly reviewed based on facts, not personal animus or politics.”

Editor's note, Janiuary 18, 2023: This story has been updated to more accurately describe Oppenheimer's role in the Manhattan Project and the consequences of the removal of his security clearance. The headline has also been changed to better reflect the actual action taken by the AEC.