Hiroshima and Nagasaki, bombings of (1945). The atomic bombing of the Japanese cities of Hiroshima and Nagasaki in August 1945 represents arguably the most important and most sinister development in warfare in the 20th century. By the early 1940s scientists in Britain and the USA were rapidly developing the technology that would lead to an atomic weapon. It was research conducted under the deepest secrecy for fear that Nazi scientists would be able to obtain the necessary data to enable them to produce a weapon of their own. In mid-1942 a programme code-named the Manhattan Project was set up to develop a bomb. The scheme involved 100, 000 persons and took three years to complete. On 16 July 1945 the first atomic bomb was tested at a site called Trinity in New Mexico. The blast that resulted was the release of energy equivalent to 20 kilotons of TNT. The steel tower on which the device was mounted completely vaporized, and the sand around melted to glass.
Hiroshima became the target of the first weapon at 08.15 on 6 August 1945. The all-clear had in fact sounded from an initial alert when the bomb was dropped. It was carried by a B-29 Superfortress called Enola Gay, and exploded about 602 yards (550 metres) over the city producing the equivalent of 15 kilotons of energy. Eyewitnesses reported seeing a parachute falling followed by a blast of intense heat. Between 130, 000 and 200, 000 people died, were injured, or disappeared. The Japanese government attempted to play down the impact and significance of this ominous development, which was followed a few days later by a second atomic bombing. This weapon had been destined for Kokura on the southern Japanese island of Kyushu, but cloud cover forced the crew to attack their secondary target of the shipyards of Nagasaki. The Nagasaki bomb was of about 20 kilotons but did less damage because of the local topography. It exploded above Urakami to the north of the port.
The injuries and destruction from the two bombs resulted from three factors: the intense blast, similar to that from conventional weapons but on a much larger scale; thermal radiation causing burns and producing fires; and nuclear radiation, which caused death and injury from damaged tissues. Each of the three effects was found on victims within 1 mile (1.6 km) from the epicentre, but the first two factors caused most deaths.
Even though more people died in the conventional bombing of Tokyo, the atomic bombings were significant because they caused death on a huge scale from one bomb dropped by one plane. Hiroshima and Nagasaki remain potent symbols and a sterile controversy over the use of the atomic weapons continues. In purely military terms the bombs proved decisive in persuading the Japanese government to think the unthinkable and accept defeat.
— Stephen Turnbull/Richard Holmes
The Oxford Companion to Military History. Copyright © 2001, 2004 by Oxford University Press. All rights reserved.
