ATOMIC AGE, DAWN OF

The Manhattan Project

Harry Truman had been vice president for only five months when Roosevelt died on April 12, 1945. He knew nothing of the Manhattan Project. Prior to the vice presidency, Truman had been just a peppery and blunt but obscure senator from Missouri. As a national political figure, he was unknown, having only just replaced Henry Wallace, an ultraliberal, as FDR’s running mate in 1944. Certainly, he was unloved (he received one of the lowest popularity ratings in presidential history), for the nation mourned the much-elected FDR and worried about whether the unproven Truman could lead America at a crucial moment in its history.

Truman became president on April 12, 1945, as the war with Japan dragged on, and relations with the Soviet Union were also growing tense over the balance of power in postwar Europe. Days after Truman’s inauguration, he was told of the atomic bomb and its development under the direction of physicist J. Robert Oppenheimer.

Dr. J. Robert Oppenheimer. (1904-1967)

"I have blood on my hands." (March 1946)

During the twenties and thirties, American physicist Julius Robert Oppenheimer became a world leader in theoretical physics. The son of a well-to-do textile importer, Oppenheimer graduated from Harvard in 1925 and received his Ph.D. from the University of Gottingen, Germany, two years later. In the late thirties, Oppenheimer wrote the first paper theorizing the existence of black holes in the universe.

In 1939, with many research fellowships and academic positions to his credit, Oppenheimer was named director of the Manhattan Project, the U.S. government’s effort to build an atomic weapon. Under Oppenheimer’s guidance, the Trinity bomb was built and tested at Alamogordo, New Mexico.

The bomb’s success had a paradoxical result for its inventors, who came to dread the terrible power they had let loose on the world. Led by Oppenheimer himself, the Association of Los Alamos Scientists (ALAS) was formed in August 1945 and lobbied for control of the weapon, advocating that the U.S. share the bomb with the rest of the world to prevent anyone from having arms superiority. By 1947, the movement had several thousand members, though it never achieved its aims. Despite Oppenheimer’s feelings of guilt over his role in the bomb’s creation, ironically, his reputation in this field was only enhanced by the bomb.

After the war, Oppenheimer directed the Institute for Advanced Study at Princeton (where Albert Einstein had also worked), until his death from cancer in 1967. During his tenure there, he was awarded the Medal for Merit by President Truman in 1946 and continued to advise the government on nuclear issues. As a member of the Lilienthal Committee, for example, Oppenheimer devised a plan that became the core of U.S. policy regarding international control of nuclear energy. As chairman of the General Advisory Committee of Atomic Energy from 1946 to 1952, Oppenheimer helped develop further military capabilities for nuclear energy, including urging the government to develop the powerful hydrogen bomb.

After a career of distinguished service to his country, and having unleashed the atom’s lethal power on the world, Oppenheimer was investigated by the House Un-American Activities Committee (HUAC). He was also put under close surveillance by the FBI for what he admitted were Communist activities in high school and college, but for which he offered no apology, saying simply, "Most of what I believed then, now seems complete nonsense, but it was an essential part of becoming a whole man. If it hadn’t been for this late but indispensable education, I couldn’t have done the job at Los Alamos."

To the HUAC he argued for the bomb’s use only against military, not civilian, targets. The threat of bombing military targets alone, he said, would achieve America’s goal of keeping the Soviets out of western Europe. Even if nuclear bombs were used against Soviet cities, Russians could still invade western Europe. The army largely supported this view, as tactical nuclear weapons enlarged its power. But these statements only fueled the HUAC’s accusations of procommunist sympathies, and it revoked Oppenheimer’s security clearance. Not until 1963 did the government redress this slight when President Kennedy awarded Oppenheimer the Fermi Award, but his security clearance was never fully restored.

Truman was surprised at the expected power of the bomb and the years of secrecy surrounding such a huge government project. The Manhattan Project had one hundred thousand people building two uranium processing plants, conducting research, and manufacturing bombs, all at a cost of two billion dollars. Truman was further surprised to learn that the first bomb was almost ready for testing and that it promised to yield the destructive power of twenty thousand tons of TNT.

Uncertain that the bomb would work, Truman planned the Japanese invasion for November to finish the war once and for all. Military advisors predicted a million casualties. Truman wondered what such a death toll would do to American morale, but he appeared to have no alternative.