An Atomic Bomb Detonates Over Hiroshima (Library of Congress Prints and Photographs Division)
On August 6, 1945, the final shot of World War Two and the first shot of the Cold War was fired as an atomic bomb on the Japanese city of Hiroshima followed by a second bomb dropped on Nagasaki. These bombings brought a new weapon of war in to the fray and changed the calculus for all war fighting decisions going forward. As the cold war marched on the undercurrent of an increasingly tense arms race gripped both the United States in the USSR. The threat of mutually assured destruction affected the civilian populations of both nations, the possibility of a limited strike on a military target sparking world war two.