The denial of security clearance in 1954 marked the end of Oppenheimer's government advisory career. Despite receiving the Enrico Fermi Award in 1963, he never regained his clearance. Over 50 years after his death, in December 2022, the U.S. Department of Energy acknowledged the unfairness of the decision and vacated the revocation.
Oppenheimer's opposition to the hydrogen bomb stemmed from his worries about the escalating destructive power and potential consequences of an arms race. His stance clashed with the Atomic Energy Commission's direction, leading to conflicts with Chairman Lewis Strauss.
During the security hearing, the FBI, through illegal phone tapping, contributed to the argument that Oppenheimer's communist associations posed a security threat. This occurred during the McCarthy era when anti-communist sentiments were widespread in the U.S. government.
Despite the setback, Oppenheimer continued to contribute to physics and nuclear technology. He received the Enrico Fermi Award from President Kennedy but remained excluded from government advisory roles until his death in 1967.
It wasn't until December 2022 that the U.S. Department of Energy officially acknowledged the injustice of Oppenheimer's security clearance revocation. This decision, long advocated by scientists and historians, coincided with the scheduled release of the movie "Oppenheimer."
Oppenheimer's complex legacy involves a historical reevaluation of his contributions and the impact of McCarthy-era suspicions. The acknowledgment of the unfair treatment in recent years underscores the ongoing process of understanding Oppenheimer's role in shaping nuclear history.