After the war, Oppenheimer was appointed the head of the U.S. Atomic Energy Commission. His conscience plagued by the devastation he had helped to create at Hiroshima and Nagasaki, Oppenheimer actively lobbied against the creation of a more powerful hydrogen bomb. Contrary to popular belief, Oppenheimer was not against the creation of more nuclear weapons, and was in fact testified in front of Congress in favor of permanently putting the Manhattan Project in the control of the military. He however was in favor of responsible control of the nuclear arsenal, as it had the power to destroy the world and he felt responsible for its creation. He served in Washington on many committee’s involved with nuclear power from 1946-1953. But the advent of McCarthyism proved his downfall.
In 1953, during Joseph McCarthy’s hunt for Communists, attention turned to Oppenheimer’s past. President Eisenhower had ordered a review on all people with security clearance to clear them of Communist sympathies. Oppenheimer had, in his own words, been “a member of about every Communist Front organization on the West Coast.” Though he himself was not a communist, he had many ties to the Party. On top of this, a former government official had passed FBI director J. Edgar Hoover a note stating that Oppenheimer was a Soviet spy. The government revoked his security privileges. Instead of resigning, Oppenheimer chose to demand a hearing. This ultimately proved to be the wrong choice.
In 1954, the Atomic Energy Commission held a hearing over Oppenheimer’s revoked privileges. It quickly degenerated into humiliation of Oppenheimer’s stance on the development of the H-bomb as “un-American.” He was attacked for being soft on Communism. He made little effort to defend himself, seemingly uncaring as to his own fate. In the end, the committee voted 4-1 against reinstating him, stating that he was a risk due to “fundamental defects in his character.”
Oppenheimer returned to collegiate life, taking a post at Princeton. He spent most of the rest of his days in relative obscurity, publishing a series of articles on ethics and morality near the end of his life. He had seemed to lose his fire for scientific work with his denouncement. The scientific community was shocked and torn on what had happened to Oppenheimer, and he remains one of the most significant victims of McCarthyism. Oppenheimer succumbed to throat cancer in 1967.