List of countries with nuclear weapons

There are currently five states considered to be "nuclear weapons states", an internationally recognized status conferred by the Nuclear Non-Proliferation Treaty (NPT). In order of acquisition of nuclear weapons these are: the United States of America, Russia (formerly the Soviet Union), the United Kingdom, France, and the People's Republic of China. Since the formulation of the NPT, two non-signatory states of the NPT have conducted nuclear tests—India and Pakistan. North Korea has publicly declared itself to possess nuclear weapons though it has not conducted any confirmed tests and its ultimate status is still unknown. Israel is strongly suspected to have an arsenal of nuclear weapons though it has never confirmed or denied this. There have been reports that over 100 nuclear weapons might be in their inventory. This status is not formally recognized by international bodies; none of these countries are currently signatories of the Nuclear Non-Proliferation Treaty. There is some speculation that Iran has, or is preparing for, a secret nuclear weapons program. South Africa was once a nuclear weapons state but has since destroyed its former arsenal.

Declared nuclear states and their first tests

• {{flagicon|USA}} The United States developed the first atomic weapons during World War II out of the fear that Nazi Germany would first develop them. It tested its first nuclear weapon in 1945 ("Trinity"), and remains the only country to have used nuclear weapons against another nation in war, during the atomic bombings of Hiroshima and Nagasaki (see: Manhattan Project). It was the first nation to develop the hydrogen bomb, testing it ("Ivy Mike") in 1952 and a deployable version in 1954 ("Castle Bravo").
• {{flagicon|USSR}} The USSR tested its first nuclear weapon ("Joe-1") in 1949, in a crash project developed partially with espionage obtained during and after World War II (see: Soviet atomic bomb project). The direct motivation for their weapons development was the development of a balance of power during the Cold War. It tested a primitive hydrogen bomb in 1953 ("Joe-4") and a megaton-range hydrogen bomb in 1955 ("RDS-37"). After its dissolution in 1991, its weapons entered officially into the possession of {{flagicon|Russia}} Russia.
• {{flagicon|United Kingdom}} The United Kingdom tested its first nuclear weapon ("Hurricane") in 1952, drawing largely on data gained while collaborating with the United States during the Manhattan Project. Its program was motivated to have an independent deterrence against the USSR, while also remaining relevant in Cold War Europe. It tested its first hydrogen bomb in 1957.
• {{flagicon|France}} France tested its first nuclear weapon in 1960, also as an independent deterrence and to retain perceived Cold War relevance (see: Force de frappe). It tested its first hydrogen bomb in 1968.
• {{flagicon|China}} The People's Republic of China tested its first nuclear weapon in 1964, much to the surprise of Western intelligence agencies. It had long sought assistance in becoming a nuclear power from an uneasy USSR, but assistance stopped after the Sino-Soviet split and the weapon was developed as a deterrent against both the USA and the USSR. It tested its first hydrogen bomb in 1967.
• {{flagicon|India}} India tested a "peaceful nuclear device", as it was described by their government, in 1974 ("Smiling Buddha"), the first test developed after the creation of the NPT, and created new questions about how civilian nuclear technology could be diverted secretly to weapons purposes (dual-use technology). It appears to have been primarily motivated as a deterrent against China. It tested weaponized nuclear warheads in 1998 ("Operation Shakti"), and also claimed to have tested a hydrogen bomb (though the truth of this is debated). In July 2005, it was officially recognized by the United States as a "responsible nuclear" state and agreed to full nuclear cooperation between the two nations. This is seen as an "official" entry into the nuclear club of the above nations.
• {{flagicon|Pakistan}} Pakistan covertly developed its nuclear weapons over many decades, with active Chinese assistance, begining in the late 1970's, and tested its first fission devices in 1998. It seems to have been motivated primarily in creating a deterrence against India. The country's proliferation record is gravely suspect. The chief scientist who worked on the Pakistani bomb, A.Q. Khan, confessed in 2004 to illicitly distributing nuclear-enabling technology to many other countries, including Iran, Libya and North Korea.