Opened for signature in 1968, the Treaty entered into force in 1970. On 11 May 1995, the Treaty was extended indefinitely. A total of 190 parties have joined the Treaty, with five states being recognized as nuclear-weapon states: the United States, Russia, the United Kingdom, France, and China (also the five permanent members of the United Nations Security Council).

Four non-parties to the treaty are known or believed to possess nuclear weapons: India, Pakistan and North Korea have openly tested and declared that they possess nuclear weapons, while Israel has had a policy of opacity regarding its own nuclear weapons program. North Korea acceded to the treaty in 1985, but never came into compliance, and announced its withdrawal in 2003.

he NPT is often seen to be based on a central bargain: "the NPT non-nuclear-weapon states agree never to acquire nuclear weapons and the NPT nuclear-weapon states in exchange agree to share the benefits of peaceful nuclear technology and to pursue nuclear disarmament aimed at the ultimate elimination of their nuclear arsenals".[




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Israel is widely believed to possess nuclear weapons[6][7] and to be the sixth country in the world to develop them.[1] It is one of four nuclear-armed countries not recognized as a Nuclear Weapons State by the Nuclear Non-Proliferation Treaty (NPT), the others being India, Pakistan and North Korea.[8] Israel maintains a policy known as "nuclear ambiguity" (also known as "nuclear opacity").[9][10] Israel has never officially admitted to having nuclear weapons, instead repeating over the years that it would not be the first country to "introduce" nuclear weapons to the Middle East, leaving ambiguity as to whether it means it will not create, will not disclose, will not make first use of the weapons or possibly some other interpretation of the phrase.[11] The "not be the first" formulation goes back to before March 11, 1965, when a cable from the U.S. Embassy in Tel Aviv to Washington noted "The Government of Israel has reaffirmed that Israel will not be the first to introduce nuclear weapons into the Arab-Israel area."[12] Israel has refused to sign the NPT despite international pressure to do so, and has stated that signing the NPT would be contrary to its national security interests.[13]
Israel started investigating the nuclear field soon after its founding in 1948 and with French support secretly began building a nuclear reactor and reprocessing plant in the late 1950s. Israel is alleged to have developed a nuclear weapon in the late 1960s, but it is not publicly confirmed.[dubious – discuss] Mordechai Vanunu, a former Israeli nuclear technician, provided explicit details and photographs to the London Sunday Times of a nuclear weapons program[14] in which he had been employed for nine years, "including equipment for extracting radioactive material for arms production and laboratory models of thermonuclear devices."[15]
Estimates as to the size of the Israeli nuclear arsenal vary between 75 and 400 nuclear warheads, with most estimates at less than 200 warheads. It is also estimated that Israel has the ability to deliver them by the intercontinental ballistic missile Jericho III, aircraft, and submarine.[2]