Instruct: Given a question, retrieve passages that answer the question.
Query: Which countries are known to have nuclear weapons?
There are eight sovereign states that have successfully detonated nuclear weapons.[1] Five are considered to be nuclear-weapon states (NWS) under the terms of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). In order of acquisition of nuclear weapons these are: the United States, Russia (the successor state to the Soviet Union), the United Kingdom, France, and China.
Although the arms race and the Cold War, which were focuses of the "Bulletin" for many of the earlier years, are no longer occurring, the publication still focuses on the nuclear dangers that exist in the world today. As more countries such as Pakistan and India have tested nuclear weapons, the "Bulletin" has focused on the dangers posed by these countries. The "Bulletin's" bi-monthly "Nuclear Notebook" is written by Federation of American Scientists experts Hans Kristensen and Matt Korda and tracks the number of nuclear weapons in the world by country. Robert "Stan" Norris, who was a founding co-author of the Nuclear Notebook, retired from the Notebook in 2018, although he is still a senior fellow at FAS. In 2015, the "Bulletin" added the Nuclear Notebook Interactive, an infographic that illustrates which countries have nuclear weapons and when they got them, and how many nuclear warheads they have in any given year. All nine nuclear-armed states are featured: the United States, Russia, China, India, Pakistan, France, Britain, Israel, and North Korea.
Saudi Arabia is not known to have a nuclear weapons program. From an official and public standpoint, Saudi Arabia has been an opponent of nuclear weapons in the Middle East, having signed the Treaty on the Non-Proliferation of Nuclear Weapons, and is a member of the coalition of countries demanding a Nuclear-weapon-free zone in the Middle East. Studies of nuclear proliferation have not identified Saudi Arabia as a country of concern.
As of April 2012 there were thirty one countries that have civil nuclear power plants, of which nine have nuclear weapons, with the vast majority of these nuclear weapons states having first produced weapons, before commercial fission electricity stations.
Moreover, the re-purposing of civilian nuclear industries for military purposes would be a breach of the Non-proliferation treaty, of which 190 countries adhere to.
Israel is widely believed to have been the sixth country in the world to develop nuclear weapons, but has not acknowledged its nuclear forces. It had "rudimentary, but deliverable," nuclear weapons available as early as 1966.[84][85][86][87][88][89][90][10] Israel is not a party to the NPT. Israel engages in strategic ambiguity, saying it would not be the first country to "introduce" nuclear weapons into the region, but refusing to otherwise confirm or deny a nuclear weapons program or arsenal. This policy of "nuclear opacity" has been interpreted as an attempt to get the benefits of deterrence with a minimum political cost.[10][11]
The triad gives countries a way to deliver a nuclear attack by land, sea or air. For the United States, the idea to have these three options was for the purpose of retaliation. If two of the three legs of the triad were destroyed, the third could still have a retaliatory strike. Also, having these three legs protects against the issue of new technology, like an enemy missile-defense system. It also gives the commander-in-chief the flexibility to use different types of weapons for the appropriate strike while also maintaining a reserve of nuclear weapons safe from a counter-force strike.Tactical nuclear weapons, also known as non-strategic nuclear weapons, are used in air, land and sea warfare. Their primary use in a non-strategic war-fighting role is to destroy military forces in the battle area. But, depending on the target in today's nuclear age, they are not counted toward triad status because of the possibility that many of these systems could be used as strategic weapons. During the Cold War, it was easy to point out which nuclear weapons were tactical. Each type of weapon had different capabilities that were better suited for different missions. Air-to-air missiles, rockets, surface-to-air missiles, small air-to-ground rockets, bombs, and precision munitions have been developed and deployed with nuclear warheads. Ground forces have included tactical nuclear artillery shells, surface-to-surface rockets, land mines, medium and small man-packable nuclear engineering demolition charges, and even man-carried or vehicle-mounted recoilless rifles. Naval forces have carried weapons that include nuclear-armed naval rockets, depth charges, torpedoes, and naval gunnery shells.
Nuclear proliferation is the spread of nuclear weapons, fissionable material, and weapons-applicable nuclear technology and information to nations not recognized as "Nuclear Weapon States" by the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), commonly known as the Non-Proliferation Treaty or NPT. Proliferation has been opposed by many nations with and without nuclear weapons, as governments fear that more countries with nuclear weapons will increase the possibility of nuclear warfare (up to and including the so-called "countervalue" targeting of civilians with nuclear weapons), de-stabilize international or regional relations, or infringe upon the national sovereignty of states.
After the bombings of Hiroshima and Nagasaki, the world’s nuclear weapons stockpiles grew, and nuclear weapons have been detonated on over two thousand occasions for testing and demonstration purposes. Countries known to have detonated nuclear weapons—and that acknowledge possessing such weapons—are (chronologically): the United States, the Soviet Union (succeeded as a nuclear power by Russia), the United Kingdom, France, the People's Republic of China, India, Pakistan, and North Korea.
Nuclear proliferation is the spread of nuclear weapons, fissionable material, and weapons-applicable nuclear technology and information to nations not recognized as "Nuclear Weapon States" by the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), commonly known as the Non-Proliferation Treaty or NPT. Proliferation has been opposed by many nations with and without nuclear weapons, as governments fear that more countries with nuclear weapons will increase the possibility of nuclear warfare (up to and including the so-called "countervalue" targeting of civilians with nuclear weapons), de-stabilize international or regional relations, or infringe upon the national sovereignty of states.
Four countries besides the five recognized Nuclear Weapons States have acquired, or are presumed to have acquired, nuclear weapons: India, Pakistan, North Korea, and Israel. None of these four is a party to the NPT, although North Korea acceded to the NPT in 1985, then withdrew in 2003 and conducted announced nuclear tests in 2006, 2009, 2013, 2016, and 2017. One critique of the NPT is that the treaty is discriminatory in the sense that only those countries that tested nuclear weapons before 1968 are recognized as nuclear weapon states while all other states are treated as non-nuclear-weapon states who can only join the treaty if they forswear nuclear weapons.
France is one of the five "Nuclear Weapons States" under the Treaty on the Non-Proliferation of Nuclear Weapons, but is not known to possess or develop any chemical or biological weapons. France was the fourth country to test an independently developed nuclear weapon in 1960, under the government of Charles de Gaulle. The French military is currently thought to retain a weapons stockpile of around 300 operational (deployed) nuclear warheads, making it the third-largest in the world, speaking in terms of warheads, not megatons. The weapons are part of the national "Force de frappe", developed in the late 1950s and 1960s to give France the ability to distance itself from NATO while having a means of nuclear deterrence under sovereign control.
Since the atomic bombings of Hiroshima and Nagasaki, nuclear weapons have been detonated over two thousand times for testing and demonstration. Only a few nations possess such weapons or are suspected of seeking them. The only countries known to have detonated nuclear weapons—and acknowledge possessing them—are (chronologically by date of first test) the United States, the Soviet Union (succeeded as a nuclear power by Russia), the United Kingdom, France, China, India, Pakistan, and North Korea. Israel is believed to possess nuclear weapons, though, in a policy of deliberate ambiguity, it does not acknowledge having them. Germany, Italy, Turkey, Belgium and the Netherlands are nuclear weapons sharing states.[4][5][6] South Africa is the only country to have independently developed and then renounced and dismantled its nuclear weapons.[7]
Israel is known to have nuclear-capable aircraft and land-base missiles, with the addition of nuclear-armed submarines this would mean that they now have a full triad of land-, air-, and sea-based nuclear delivery systems some of which would be invulnerable to a first strike by an enemy for the first time in their country's history. No other nation in the Middle East in known to be in possession of nuclear weapons, even though Iran, Iraq, Syria and Libya have started development programs that were never completed.
This table is not comprehensive, as numerous facilities throughout the United States have contributed to its nuclear weapons program. It includes the major sites related to the U.S. weapons program (past and present), their basic site functions, and their current status of activity. Not listed are the many bases and facilities at which nuclear weapons have been deployed. In addition to deploying weapons on its own soil, during the Cold War, the United States also stationed nuclear weapons in 27 foreign countries and territories, including Okinawa (which was US-controlled until 1971,) Japan (during the occupation immediately following World War II), Greenland, Germany, Taiwan, and French Morocco then independent Morocco.
After World War II, nuclear weapons were also developed by the Soviet Union (1949), the United Kingdom (1952), France (1960), and the People's Republic of China (1964), which contributed to the state of conflict and extreme tension that became known as the Cold War. In 1974, India, and in 1998, Pakistan, two countries that were openly hostile toward each other, developed nuclear weapons. Israel (1960s) and North Korea (2006) are also thought to have developed stocks of nuclear weapons, though it is not known how many. The Israeli government has never admitted or denied to having nuclear weapons, although it is known to have constructed the reactor and reprocessing plant necessary for building nuclear weapons.[10] South Africa also manufactured several complete nuclear weapons in the 1980s, but subsequently became the first country to voluntarily destroy their domestically made weapons stocks and abandon further production (1990s).[11] Nuclear weapons have been detonated on over 2,000 occasions for testing purposes and demonstrations.[12][13]
The only country to have used a nuclear weapon in war is the United States, which dropped two atomic bombs on the Japanese cities of Hiroshima and Nagasaki during World War II. There are eight countries that have declared they possess nuclear weapons and are known to have tested a nuclear weapon, only five of which are members of the NPT. The eight are China, France, India, North Korea, Pakistan, Russia, the United Kingdom, and the United States.
Iran states it has a legal right to enrich uranium for peaceful purposes under the NPT, and further says that it "has constantly complied with its obligations under the NPT and the Statute of the International Atomic Energy Agency". Twelve other countries are known to operate uranium enrichment facilities. Iran states that "the failure of certain Nuclear- Weapon States to fulfill their international obligations continue to be a source of threat for the international community". Iran also states that "the only country that has ever used nuclear weapons still maintains a sizable arsenal of thousands of nuclear warheads" and calls for a stop to the transfer of technology to non-NPT states. Iran has called for the development of a follow-up committee to ensure compliance with global nuclear disarmanent. Iran and many other nations without nuclear weapons have said that the present situation whereby Nuclear Weapon States monopolise the right to possess nuclear weapons is "highly discriminatory", and they have pushed for steps to accelerate the process of nuclear disarmament.
Nuclear weapons have also been opposed by agreements between countries. Many nations have been declared Nuclear-Weapon-Free Zones, areas where nuclear weapons production and deployment are prohibited, through the use of treaties. The Treaty of Tlatelolco (1967) prohibited any production or deployment of nuclear weapons in Latin America and the Caribbean, and the Treaty of Pelindaba (1964) prohibits nuclear weapons in many African countries. As recently as 2006 a Central Asian Nuclear Weapon Free Zone was established among the former Soviet republics of Central Asia prohibiting nuclear weapons.
In August 2008, the International Atomic Energy Agency (IAEA) approved safeguards agreement with India under which the former will gradually gain access to India's civilian nuclear reactors. In September 2008, the Nuclear Suppliers Group granted India a waiver allowing it to access civilian nuclear technology and fuel from other countries. The implementation of this waiver makes India the only known country with nuclear weapons which is not a party to the NPT but is still allowed to carry out nuclear commerce with the rest of the world. 
The State of Israel is widely believed to possess nuclear weapons. Current estimates put the size of the Israeli nuclear arsenal at between 80 and 400 nuclear warheads, and the country is believed to possess the ability to deliver them in a variety of methods including: aircraft; submarine-launched cruise missiles; and the Jericho series of intermediate to intercontinental range ballistic missiles. Its first deliverable nuclear weapon is thought to have been created in late 1966 or early 1967; which would make it the sixth country in the world to have developed them.
A nuclear-weapons-free zone (NWFZ) is defined by the United Nations as an agreement which a group of states has freely established by treaty or convention that bans the use, development, or deployment of nuclear weapons in a given area, that has mechanisms of verification and control to enforce its obligations, and that is recognized as such by the General Assembly of the United Nations.
NWFZs have a similar purpose to, but are distinct from, the Treaty on the Non-Proliferation of Nuclear Weapons to which most countries including five nuclear weapons states are party. Another term, nuclear-free zone, often means an area which has banned both nuclear power and nuclear weapons, and sometimes nuclear waste and nuclear propulsion, and usually does not mean a UN-acknowledged international treaty.
Nuclear sharing is a concept in NATO's policy of nuclear deterrence, which involves member countries without nuclear weapons of their own in the planning for the use of nuclear weapons by NATO. In particular, it provides for the armed forces of those countries to be involved in delivering nuclear weapons in the event of their use.
The United Kingdom became a nuclear power in 1952, and their nuclear arsenal peaked at just under 500 nuclear weapons in 1981. France became a nuclear power in 1960, and French nuclear stockpiles peaked at just over 500 nuclear weapons in 1992. China developed its first nuclear weapon in 1964; its nuclear stockpile increased until the early 1980s, when it stabilized at between 200 and 260. India became a nuclear power in 1974, while Pakistan developed its first nuclear weapon in the 1980s. India and Pakistan currently have around one hundred nuclear weapons each. Pakistan's nuclear stockpile has increased rapidly, and it is speculated that Pakistan might have more nuclear weapons than the United Kingdom within a decade.
Other observers have suggested that the linkage between proliferation and disarmament may also work the other way, i.e., that the failure to resolve proliferation threats in Iran and North Korea, for instance, will cripple the prospects for disarmament. No current nuclear weapons state, the argument goes, would seriously consider eliminating its last nuclear weapons without high confidence that other countries would not acquire them. Some observers have even suggested that the very progress of disarmament by the superpowers—which has led to the elimination of thousands of weapons and delivery systems—could eventually make the possession of nuclear weapons more attractive by increasing the perceived strategic value of a small arsenal. As one U.S. official and NPT expert warned in 2007, "logic suggests that as the number of nuclear weapons decreases, the 'marginal utility' of a nuclear weapon as an instrument of military power increases. At the extreme, which it is precisely disarmament's hope to create, the strategic utility of even one or two nuclear weapons would be huge."
These countries are weary of nuclear weapons’ deployment above everything else. Although 8 states are exempted from ban on nuclear weapons, 5 nations retain a de jure status of a “nuclear weapon state.” These states are the United States of America, the United Kingdom, the People’s Republic of China, France and Russia—all of whom had already tested nuclear weapons before the NPT was signed. NWS’s right to possess a nuclear arsenal is countered by Article VI of the treaty, which says that they have a legal obligation to eventually disarm. They also criticized NWS countries for failing to meet their obligation to disarm, in addition to criticizing the 3 states non-signatory nuclear weapons-capable states (which are considered de facto nuclear weapons states). This was stated in point 4 of the Joint Declaration of 1998: