Range near Alamogordo, New Mexico. Dr. Robert Oppenheimer, director of the Manhattan Project, could hardly breathe. Years of secrecy, research, and tests were riding on this moment. "For the last few seconds, he stared directly ahead and when the announcer shouted, „Now!' and there came this tremendous burst of light followed abruptly thereafter by the deep growling of the explosion, his face relaxed into an expression of tremendous relief," recalled General L. R. Groves of Oppenheimer, in a memorandum for Secretary of War George Marshall.
The explosion, which carried more power than 20,000 tons of TNT and was visible for more than 200 miles, had succeeded. The world's first atomic bomb had been detonated. With the advent of the nuclear age, new dilemmas in the art of warfare arose. The war in Europe had concluded in May. The Pacific war would receive full attention from the United States War Department. As late as
May 1945, the U.S. was engaged in heavy fighting with the Japanese at Iwo Jima and Okinawa. In these most bloody conflicts, the United States had sustained more than 75,000 casualties. These victories insured the United
States was within air striking distance of the Japanese mainland. The bombing of Pearl Harbor by the Japanese to initiate United States entrance into the war, just four years before, was still fresh on the minds of many
Americans. A feeling of vindication and a desire to end the war strengthened the resolve of the United States to quickly and decisively conclude it. President Harry Truman had many alternatives at his disposal for ending the war: invade the Japanese mainland, hold a demonstration of the destructive power of the atomic bomb for
Japanese dignitaries, drop an atomic bomb on selected industrial Japanese cities, bomb and blockade the islands, wait for Soviet entry into the war on August 15, or mediate a compromised peace. “Operation Olympia”, a full-scale landing of United States armed forces, was already planned for the Japanese island of Kyushu on
November 1, 1945, and a bomb and blockade plan had already been instituted over the Japanese mainland for several months. The Japanese resolve to fight had been seriously hampered in the preceding months. Their losses at Iwo Jima and Okinawa had been staggering. Their navy had ceased to exist as an effective fighting force and the air corps had been decimated. American B-29 “Superfortresses” made bombing runs over military targets on the Japanese mainland an integral part of their air campaign. Japan's lack of air power hindered their ability to fight. The imprecision of bombing and the use of devastating city bombing in Europe eventually swayed United States
Pacific theater military leaders to authorize bombing of Japanese mainland cities. Tokyo, Nagoya, Osaka, and
Kobe all were decimated by