Countdown 1945: The Extraordinary Story of the Atomic Bomb and the 116 Days That Changed the World

On April 12th, 1945 Harry Truman becomes the 33rd president of the United States after the sudden death of Franklin D. Roosevelt. At the time, the Second World War is still raging. Truman intends to continue the agenda of his predecessor—telling his cabinet officials he wants everything to continue “just the way President Roosevelt wanted” (5)—and after being sworn in reiterates this intention. After the inauguration, Henry Stimson, the secretary of war, takes Truman aside and briefly mentions that he has an urgent matter to discuss with him in the coming days.

J. Robert Oppenheimer is the director of the Manhattan Project, “America’s massive secret effort to develop an atomic bomb” (7). Oppenheimer, one of the most brilliant physicists in the world, was appointed by Roosevelt. A highly idiosyncratic character, Oppenheimer is known to be quite charming and yet prone to melancholy and arrogance. Oppenheimer considers the development of the atom bomb to be the best way to end the war, and so he takes up his place at the head of the project in Los Alamos, New Mexico with a sense of determination and purpose.

Hearing of the death of FDR, Oppenheimer is worried about how Truman will view the project, especially since Roosevelt was so instrumental in smoothing over the tensions between the scientists and the military leaders.