Thousands of nuclear weapons exist in the world. The use of even one could change life as we know it.
Nine countries possess nuclear weapons: the United States, Russia, France, China, the United Kingdom, Pakistan, India, Israel, and North Korea.
Some countries first developed nuclear weapons in the context of the Cold War, as the United States and the Soviet Union jockeyed for influence. Others developed them more recently, in response to regional conflicts or other concerns.
US-Soviet and US-Russian treaties and agreements have reduced the total global stockpile of weapons, which peaked in the 1980s at some 60,000 weapons—but 9,000 still remain. The nuclear policies of these nine nations increase the risk that these weapons will be used.