History of nuclear weapons

Nuclear weapons possess enormous destructive power from nuclear fission, or a combination of fission and fusion reactions. Building on major scientific breakthroughs made during the 1930s, the United States, the United Kingdom, Canada, and France collaborated during World War II, in what was called the Manhattan Project, to build a weapon using nuclear fission, also known as an atomic bomb.[1] In August 1945, the atomic bombings of Hiroshima and Nagasaki were conducted by the United States against Japan at the close of that war, standing to date as the only use of nuclear weapons in hostilities. The Soviet Union started development shortly after with their own atomic bomb project, and not long after, both countries were developing even more powerful fusion weapons known as hydrogen bombs. Britain and France built their own systems in the 1950s, and the number of states with nuclear capabilities has gradually grown larger in the decades since.

Nuclear weapons
Background
History Warfare Design Testing Delivery Yield Effects and estimated megadeaths of explosions Winter Workers Ethics Arsenals Arms race Espionage Proliferation Disarmament Terrorism Opposition
Nuclear-armed states
NPT recognized United States Russia United Kingdom France China Others India Israel (undeclared) Pakistan North Korea Former South Africa Belarus Kazakhstan Ukraine
v t e