Currently, nine countries claim to possess nuclear weapons or are believed to possess them.
This number has remained stable for years (see the 2018 figures in the gallery below). The first to possess them were the five original nuclear-weapon states: the United States, Russia, China, France, and the United Kingdom. All five are signatories of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), which commits non-nuclear-weapon states to not build or acquire nuclear weapons, and nuclear-weapon states to “pursue negotiations in good faith” towards nuclear disarmament.
India and Pakistan are increasing their nuclear arsenal
India and Pakistan, rivals that have not signed the NPT, have increased their nuclear arsenals over the years. India was the first to conduct a nuclear test in 1974, followed by another in 1998. Pakistan conducted its own nuclear tests just a few weeks later.
Israel, which has also not signed the NPT, has never acknowledged having nuclear weapons, but it is widely believed to possess them. North Korea joined the NPT in 1985, but announced its withdrawal from the treaty in 2003, citing what it called U.S. aggression. Since 2006, it has conducted a series of nuclear tests.
Iran and its nuclear enigma
Iran has long insisted that its nuclear program is exclusively for peaceful purposes, and US intelligence agencies have determined that Tehran is not actively seeking a nuclear bomb. However, in recent years, it has been enriching uranium up to 60% purity, close to 90%, a level suitable for nuclear weapons.
In an annual assessment published in June 2025, the Stockholm International Peace Research Institute (SIPRI) estimated that the nine countries had the following reserves of military nuclear warheads in January of that same year:
- Russia: 4,309 (out of 8,500 estimated in 2018)
- United States: 3,700 (in 2018 an estimated 7,700 were estimated)
- China: 600 (increase from 250 estimated in 2018)
- France: 290
- United Kingdom: 225 (out of 215 in 2018 estimate)
- India: 180 (estimated increase of 70 in seven years)
- Pakistan: 170 (30 more than the estimated in 2018)
- Israel: 90
- North Korea: 50 (out of 60 estimated seven years ago)