NUCLEAR WEAPONS STATES
Part 1

List of countries with nuclear weapons.

This is a list of countries with nuclear weapons. There are currently eight states that have successfully detonated nuclear weapons. Five are 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 (successor state to the Soviet Union), the United Kingdom, France and China. Since the formulation of the NPT, three non-signatory states of the NPT have conducted nuclear tests: India, Pakistan, and purportedly North Korea. Additionally, Israel is also strongly suspected to have an arsenal of nuclear weapons though it has refused to confirm or deny this, and there have been reports that over 200 nuclear weapons might be in its inventory. This status is not formally recognized by international bodies as none of these four countries are currently signatories to the Nuclear Non-Proliferation Treaty. Iran has been developing uranium enrichment technology and stands accused by the United States of doing so for weapons uses. Iran insists that its intentions are limited to domestic nuclear power generation, despite plutonium traces being detected. As of February 4, 2006, the International Atomic Energy Agency referred Iran to the United Nations Security Council in response to concerns on their possible nuclear programs.

Five "nuclear weapons countries" from the NPT

An early stage in the "Trinity" fireball, the first nuclear explosion.

The United States of America developed the first atomic weapons during World War II in co-operation with the United Kingdom and Canada, out of the fear that Nazi Germany would develop them first. It tested its first nuclear weapon in 1945 ("Trinity"), and remains the only country to have used nuclear weapons against another nation, during the atomic bombings of Hiroshima and Nagasaki. It was the first nation to develop the hydrogen bomb, testing it ("Ivy Mike") in 1952 and a deployable version in 1954 ("Castle Bravo").

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. 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"). The Soviet Union also tested the most powerful explosive ever detonated by humans, ("Tsar Bomba"), which had a yield of 100 megatons, but was intentionally reduced to 50. After its dissolution in 1991, its weapons entered officially into the possession of Russia.

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 deterrent against the USSR, while also remaining relevant in Cold War Europe. It tested its first hydrogen bomb in 1957. It maintains the Trident fleet of nuclear weapon submarines.

French nuclear-powered tactical nuclear bombers carrier Charles de Gaulle and the American nuclear-powered carrier USS Enterprise.

France tested its first nuclear weapon in 1960 ("Gerboise Bleue"), based mostly on its own research aided by indirect British help[citations needed] and the experience of French scientists who had worked on the Manhattan Project namely Louis de Broglie, Pierre Auger and Frédéric Joliot. It was motivated by the will of independence vis-à-vis the United States confirmed with France's loosening of ties to NATO, and as an independent deterrent against the USSR. It was also relevant to retain great power status, along side United Kingdom, during the post-colonial Cold War. France tested its first hydrogen bomb in 1968 ("Operation Canopus"). After the Cold War, France has disarmed 175 warheads with the reduction and modernization of its arsenal which has now evolved to a dual system based on submarine-launched ballistic missiles (SSBN) and medium-range air-to-surface missiles (Rafale bombers). However new nuclear weapons are in development and reformed nuclear squadrons were trained during Enduring Freedom operation in Afghanistan. In January 2006, president Jacques Chirac officially stated a terrorist act or the use of weapons of mass destruction against France would result in a nuclear counterattack The Charles de Gaules is currently the last carrier with nuclear weapons deployed by a country.

China tested its first nuclear weapon in 1964. China was the first Asian nation to have developed and tested a nuclear weapon. The weapon was developed as a deterrent against both the United States and the USSR. It tested its first hydrogen bomb in 1967 at Lop Nur. The country is currently thought to have had a stockpile of around 130 warheads.