During World War II (1939-45), an American B-29 bomber, the world’s first deployed atomic bomb, was dropped over the Japanese city of Hiroshima on August 6, 1945. An estimated 80,000 people were killed immediately by the explosion and tens of thousands more died later as a result of radiation exposure.
A second B-29 dropped another A-bomb on Nagasaki three days later, killing an estimated 40,000 people. In a radio address on August 15, Japan’s Emperor Hirohito announced his country’s unconditional surrender in World War II, citing the devastating power of “a new and most cruel bomb.”
Though the dropping of the atomic bomb on Japan ended World War II, many historians argue that it also sparked the Cold War. After being warned that Nazi Germany was already conducting nuclear weapons research, the United States began working on developing an atomic weapon in 1940.
When Was Hiroshima Bombed?
- A. 5 August 1944
- B. 6 August 1945
- C. 7 August 1946
- D. 8 August 1947
Germany had already been defeated by the time the United States conducted the first successful test (an atomic bomb was exploded in the desert of New Mexico in July 1945).
Hiroshima and Nagasaki Bombing
Since the two atomic bombs were dropped on Japan, a number of historians have proposed that the weapons served a dual purpose. The first priority, of course, was to end the war with Japan quickly and save American lives. It has been suggested that the second goal was to demonstrate the new weapon of mass destruction to the Soviet Union.
Relations between the Soviet Union and the United States had deteriorated significantly by August 1945. The Potsdam Conference, which included US President Harry S. Truman, Russian leader Joseph Stalin, and Winston Churchill, ended just four days before the Hiroshima bombing.
Between the Americans and the Soviets, the meeting was marked by recriminations and suspicion. Russian armies occupied the majority of Eastern Europe. Truman and many of his advisers hoped that the United States’ nuclear monopoly would provide diplomatic leverage with the Soviets. In this sense, the dropping of the atomic bomb on Japan can be regarded as the opening salvo of the Cold War.
The devastating effects of both kinds of bombs depended essentially upon the energy released at the moment of the explosion, causing immediate fires, destructive blast pressures, and extreme local radiation exposures. Since the bombs were detonated at a height of some 600 meters above the ground, very little of the fission products were deposited on the ground beneath.