politicsOur World in Data
Nine countries are known or widely believed to hold nuclear weapons, and their arsenals are very unevenly sized
Nine countries possess nuclear weapons: the United States, Russia, the United Kingdom, France, China, India, Pakistan, Israel and North Korea. Russia and the United States hold the vast majority of the world's warheads, with thousands each, while the others have far smaller stockpiles. Israel has never confirmed having nuclear weapons, and North Korea is the only state to have tested them in the 21st century. Only the five states recognised under the Nuclear Non-Proliferation Treaty are considered official nuclear-weapon states under it, which excludes India, Pakistan, Israel and North Korea.
A nuclear weapon releases energy from splitting or fusing atoms, far more than any conventional explosive. Possession is limited by the cost and difficulty of enriching fissile material and building delivery systems, which is why only a few states have them. The Nuclear Non-Proliferation Treaty of 1968 created a framework recognising five nuclear states while asking others not to acquire weapons.
Knowing who holds these weapons, and how many, shapes every debate about arms control and deterrence. Most of the world's warheads are held by two countries, so their agreements matter far more than any others.
Nuclear weapons spread from the US in 1945 to the Soviet Union in 1949, then to the UK, France, China, and later India, Pakistan, and North Korea. The number of states holding them has risen only slowly since the treaty, despite fears of wider spread.
