9781422285954

The Cold War

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plans for postwar Europe. He thought Stalin would see that the Soviet Union had little to gain from a confrontation with the United States. The president’s optimismwas bolstered by news he’d received on the eve of the Potsdam Conference. On July 16, scientists working on a top-secret program called the Manhattan Project successfully tested a new type of weapon. In a remote area of NewMexico, they detonated the world’s first atomic bomb. The explosion was unlike anything seen before. It carried the force of about 21 kilotons (21,000 tons) of dynamite. The Manhattan Project had overcome enormous scientific and engi- neering hurdles to create the atomic bomb. Scientists and engineers in the USSR would eventually figure out how to do so as well. But many American military experts believed that would take at least a decade. In the meantime, the United States would be the only country to possess the most destructive weapon ever created. Soviet leaders would have to take into account the U.S. monopoly on atomic weapons. President Truman thought the Soviets would be a bit more cooperative as a result. Secretary of State James Byrnes had greater expectations. Byrnes believed that “in the last analysis, [the atomic bomb] would control” Soviet behavior. In August 1945, the world witnessed the terrible power of the new weapon. The United States used two atomic bombs to destroy two Japa- nese cities, Hiroshima and Nagasaki. More than 100,000 people were killed immediately. Tens of thousands would die later from the effects of radiation. Japan announced its surrender five days after the Naga- saki bombing.

The atomic bomb used a process called nuclear fission. Fis- sion is a chain reaction during which the nuclei (centers) of uranium or plutonium atoms are split apart. A tremendous amount of energy is released as a result.