The American theoretical physicist who led the scientific work of the Manhattan Project at Los Alamos, building the first nuclear weapons — used weeks later on Hiroshima and Nagasaki — and who spent much of the rest of his life warning about what he had helped make: opposing a crash program for the hydrogen bomb, urging international control, and then being stripped of his security clearance in a 1954 hearing widely condemned as a political show trial, a decision the United States government formally vacated in 2022.
J. Robert Oppenheimer built the weapon he came to fear. He was a brilliant, restless physicist who led the secret laboratory in the New Mexico desert that designed the first atomic bombs. When the first one exploded in July 1945, he later said, a line from a Hindu scripture rose in his mind: "Now I am become Death, the destroyer of worlds." Weeks later, two of those bombs killed well over a hundred thousand people at Hiroshima and Nagasaki. He had given his country the power to end cities in a flash, and the rest of his life was shadowed by it. When he warned against the far larger hydrogen bomb and the arms race ahead, his enemies used his old left-wing ties to strip his security clearance in a 1954 hearing many saw as a show trial. He was one of the most celebrated and most divisive figures in American science, and he never resolved the contradiction at his center: the patriot who armed the country, and the conscience who begged it to stop.