In October 16, 1945, Oppenheimer resigned from his position as director of Los Alamos, intending to return to academic life. Within two years, he was appointed to the directorship of Princeton University's Institute for Advanced Study, the world-renowned center of thought whose best known scholar in resident was Albert Einstein.
But academia proved too tame for Oppenheimer. His years at Los Alamos had given him a taste for power, fame, and the shaping of public policy, and he wasn't yet ready to turn his back on public life. Oppenheimer had never succeeded in making a name for himself as a physicist, but he'd had phenomenal success as an administrator and public figure–the government welcomed him back into service with open arms.
Oppenheimer had become an international symbol for the success of American physics, and his popularity and experience easily translated into prestige and influence in Washington, D.C. The creation of the atomic bomb represented an amazing achievement for the United States, but now the United States, specifically the United States government, needed to figure out what to do with it. Oppenheimer was ready and willing to put in his two cents.
Shortly after Hiroshima, Oppenheimer testified in support of the May-Johnson bill, which turned the Manhattan Project into a permanent program and gave permanent control of the project over to the military. Oppenheimer supported the bill in the hopes that it represented a move toward some form of international control over nuclear power. However, many of his colleagues were appalled that any scientist would support putting science into the hands of the government. They questioned whether the taste of political power had corrupted his scientific integrity.
Undaunted by criticism, Oppenheimer continued in his attempt to place the nuclear arsenal under international control. In 1946, Oppenheimer helped to author a plan that would be presented to the United Nations Atomic Energy Committee. Known as the Baruch Plan, the program would establish a world authority, to be administered by the UN, that would control all atomic energy research and development. The Soviet Union would open its labs to international inspection, and the United States would turn its bombs into power plants. When Bernard Baruch, Truman's designated representative, presented the idea to the UN, he insisted that under his plan, no nation could have veto power. Insistent on not compromising their veto power, the Soviet Union immediately rejected the Baruch Plan. It's likely that the Soviets would have rejected the plan no matter what, as it did not fit into their nuclear strategy–to either eliminate the United States' nuclear arsenal, or to develop their own nuclear weapons as soon as possible. The United States and the Soviet Union were deadlocked, and negotiations soon fell apart.
Oppenheimer never lost sight of his goal, however, which was to establish some form of peaceful, international control over nuclear weaponry or, barring that, to ensure that the United States government acted responsibly when it came to the American nuclear arsenal. Contrary to what some later believed, Oppenheimer was not against nuclear weapons. In fact, he agreed with the majority of the country that nuclear weapons were essential to protecting the nation's security. However, Oppenheimer would always feel partly responsible for introducing nuclear weapons into the world and felt it was his responsibility to monitor and attempt to influence how they were used.