The Oppenheimer security hearing was a 1954 proceeding by the United States Atomic Energy Commission (AEC) that explored the background, actions, and associations of J. Robert Oppenheimer, the American scientist who had headed the Los Alamos Laboratory during World War II, where he played a key part in the Manhattan Project that developed the atomic bomb. The hearing resulted in Oppenheimer's Q clearance being revoked. This marked the end of his formal relationship with the government of the United States, and generated considerable controversy regarding whether the treatment of Oppenheimer was fair, or whether it was an expression of anti-Communist McCarthyism. Doubts about Oppenheimer's loyalty dated back to the 1930s, when he was a member of numerous Communist front organizations, and was associated with Communist Party USA members, including his wife and his brother. These associations were known to Army Counterintelligence at the time he was made director of the Los Alamos Laboratory in 1942, and chairman of the influential General Advisory Committee of the AEC in 1947. In this capacity Oppenheimer became involved in bureaucratic conflict between the Army and Air Force over the types of nuclear weapons the country required, technical conflict between the scientists over the feasibility of the hydrogen bomb, and personal conflict with AEC commissioner Lewis Strauss. The proceedings were initiated after Oppenheimer refused to voluntarily give up his security clearance while working as an atomic weapons consultant for the government, under a contract due to expire at the end of June 1954. Several of his colleagues testified at the hearings. As a result of the two to one decision of the hearing's three judges, he was stripped of his security clearance one day before his consultant contract was due to expire. The panel found that he was loyal and discreet with atomic secrets, but did not recommend that his security clearance be reinstated. The loss of his security clearance ended Oppenheimer's role in government and policy. He became an academic exile, cut off from his former career and the world he had helped to create. The reputations of those who had testified against Oppenheimer were tarnished as well, and Oppenheimer's reputation was later partly rehabilitated by Presidents John F. Kennedy and Lyndon B. Johnson. The brief period when scientists were viewed as a "public policy priesthood" ended, and thereafter would serve the state only to offer narrow scientific opinions. Scientists working in government were