Nations that are known or believed to possess nuclear weapons are sometimes referred to as the nuclear club. There are currently nine states that have successfully detonated nuclear weapons. Five are considered to be "nuclear weapons states" (NWS), an internationally recognized status conferred by the Nuclear Non-Proliferation Treaty (NPT). In order of acquisition of nuclear weapons these are: the United States, Russia (successor state to the Soviet Union), the United Kingdom, France, and China.

Since the NPT entered into force in 1970, three states that were not parties to the Treaty have conducted nuclear tests, namely India, Pakistan, and North Korea. North Korea had been a party to the NPT but withdrew in 2003. Israel is also widely believed to have nuclear weapons, though it has refused to confirm or deny this. The status of these nations is not formally recognized by international bodies as none of them are currently parties to the NPT. South Africa has the unique status of a nation which developed nuclear weapons but has since disassembled its arsenal before joining the NPT.

In 2005, the IAEA Board of Governors found Iran in non-compliance with its NPT safeguards agreement in a rare non-consensus decision. The UN Security Council imposed sanctions against Iran three times when it refused to suspend its previously undeclared enrichment. Iran has argued that the sanctions are illegal and compel it to abandon its rights under the NPT to peaceful nuclear technology. IAEA Director Mohamed ElBaradei states the agency is unable to resolve "outstanding issues of concerns" while also noting the Agency has "not seen any diversion of nuclear materials... nor the capacity to produce weapons usable materials".

Statistics and policies

[[Image:Nuclear weapons states.svg|thumb|400px|right|Map of nuclear weapons countries of the world.

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The following is a list of states that have admitted the possession of nuclear weapons, the approximate number of warheads under their control in 2009, and the year they tested their first weapon. This list is informally known in global politics as the "Nuclear Club". With the exception of Russia and the United States (which have subjected their nuclear forces to independent verification under various treaties) these figures are estimates, in some cases quite unreliable estimates. Also, these figures represent total warheads possessed, rather than deployed. In particular, under the SORT treaty thousands of Russian and U.S. nuclear warheads are in inactive stockpiles awaiting processing. The fissile material contained in the warheads can then be recycled for use in nuclear reactors.

From a high of 65,000 active weapons in 1985, there are now about 8,000 active nuclear warheads and about 23,300 total nuclear warheads in the world in 2009. Many of the "decommissioned" weapons were simply stored or partially dismantled, not destroyed. As of 2007, the total number was expected to continue to decline by 30%–50% over the next decade.

Nuclear weapons states, warhead numbers and policy

Country	Active	Total	First test	NPT	CTBT
United States	2623	9400	1945 Trinity	Yes	Signed
Russia (USSR)	4718	13000	1949 RDS-1	Yes	Ratified
United Kingdom	<160></160>	185	1952 Hurricane	Yes	Ratified
France	~300	300	1960 Gerboise Bleue	Yes	Ratified
China	~180	240	1964 596	Yes	Signed
India	n.a.	60–80	1974 Smiling Buddha	No	No
Israel (opaque)	n.a.	80	1979? Vela Incident	No	Signed
Pakistan	n.a.	70-90	1998 Chagai-I	No	No
North Korea	n.a.	<10></10>	2006 2006 test	Quit	No

All numbers are estimates from the Natural Resources Defense Council, published in the Bulletin of the Atomic Scientists, unless other references are given. The latest update was on October 2, 2009. If differences between active and total stockpile are known, they are given as two figures separated by a forward slash. If specifics are not available (n.a.), only one figure is given. Stockpile number may not contain all intact warheads if a substantial amount of warheads are scheduled for but have not yet gone through dismantlement; not all "active" warheads are deployed at any given time. When a range of weapons is given (e.g., 0–10), it generally indicates that the estimate is being made on the amount of fissile material that has likely been produced, and the amount of fissile material needed per warhead depends on estimates of a country's proficiency at nuclear weapon design.

Five nuclear weapons states from the NPT

The United States developed the first atomic weapons during World War II in co-operation with the United Kingdom and Canada as part of the Manhattan Project, out of the fear that Nazi Germany would develop them first. It tested the 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 an experimental version in 1952 ("Ivy Mike") and a deployable weapon in 1954 ("Castle Bravo"). Throughout the Cold War it continued to modernize and enlarge its nuclear arsenal, but from 1992 on has been involved primarily in a program of Stockpile stewardship.

The Soviet Union 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 USSR was the second nation to have developed and tested a nuclear weapon. The direct motivation for their weapons development was the development of a balance of power during the Cold War. It tested its first megaton-range hydrogen bomb in 1955 ("RDS-37"). The Soviet Union also tested the most powerful explosive ever detonated by humans, ("Tsar Bomba"), with a theoretical yield of 100 megatons, intentionally reduced to 50 when detonated. After its dissolution in 1991, the Soviets' 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. The UK was the first nation in Western Europe to have developed and tested a nuclear weapon. 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 ballistic missile fleet of four 'Vanguard' class nuclear-powered submarines. The British government controversially announced a replacement to the current Trident system to take place over the next decade.

France tested its first nuclear weapon in 1960 ("Gerboise Bleue"), based mostly on its own research. It was motivated by the Suez Crisis diplomatic tension vis-à-vis both the USSR and the Free World allies United States and United Kingdom. It was also relevant to retain great power status, alongside the United Kingdom, during the post-colonial Cold War (see: Force de frappe). France tested its first hydrogen bomb in 1968 ("Opération Canopus"). After the Cold War, France has disarmed 175 warheads with the reduction and modernization of its arsenal that has now evolved to a dual system based on submarine-launched ballistic missiles (SSBN) and medium-range air-to-surface missiles (Rafale fighter-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 stated a terrorist act or the use of weapons of mass destruction against France would result in a nuclear counterattack.

China tested its first nuclear weapon device in 1964 ("596") at the Lop Nur test site. The weapon was developed as a deterrent against both the United States and the Soviet Union. China would manage to develop a fission bomb capable of being put onto a nuclear missile only two years after its first detonation. It tested its first hydrogen bomb in 1967 ("Test No. 6"), a mere 32 months after testing its first nuclear weapon (the shortest fission-to-fusion development known in history). The country is currently thought to have had a stockpile of around 240 warheads, though because of the limited information available, estimates range from 100 to 400. China is the only nuclear weapons state to give an unqualified negative security assurance to non-nuclear weapon states and the only one to adopt a "no first use" policy.

Other known nuclear powers

India has never been a member of the Nuclear Non-Proliferation Treaty. India tested what it called a "peaceful nuclear explosive" in 1974 (which became known as "Smiling Buddha"). The test was 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). India's secret development caused great concern and anger particularly from nations that had supplied it nuclear reactors for peaceful and power generating needs such as Canada. It appears to have been primarily motivated as a general deterrent, as well as an attempt to project India as regional power. India later tested weaponized nuclear warheads in 1998 ("Operation Shakti"), including a thermonuclear device. In July 2005, U.S. President George W. Bush and Indian Prime Minister Manmohan Singh announced plans to conclude a Indo-US civilian nuclear agreement. This came to fruition through a series of steps that included India’s announced plan to separate its civil and military nuclear programs in March 2006, the passage of the United States-India Peaceful Atomic Energy Cooperation Act by the U.S. Congress in December 2006, the conclusion of a U.S.-India nuclear cooperation agreement in July 2007, approval by the IAEA of an India-specific safeguards agreement, agreement by the Nuclear Suppliers Group to a waiver of export restrictions for India, approval by the U.S. Congress and culminating in the signature of U.S.-India agreement for civil nuclear cooperation in October 2008. The U.S. State Department said it made it "very clear that we will not recognize India as a nuclear-weapon state". The United States is bound by the Hyde Act with India and may cease all cooperation with India if India detonates a nuclear explosive device. The US had further said it is not its intention to assist India in the design, construction or operation of sensitive nuclear technologies through the transfer of dual-use items. In establishing an exemption for India, the Nuclear Suppliers Group reserved the right to consult on any future issues which might trouble it.

As of September 2005, India was estimated to have had a stockpile of around 100-140 warheads. In addition, Defense News reported in their November 1, 2004 edition, that "[an Indian] Defence Ministry source told Defense News in late 2004 that in the next five to seven years India will have 300–400 nuclear and thermonuclear weapons distributed to air, sea, and land forces." It has estimated that India currently possesses enough separated plutonium to produce and maintain an arsenal of 1,000-2,000 warheads.

Pakistan is not a member of the Nuclear Non-Proliferation Treaty either. Pakistan covertly developed nuclear weapons over many decades, beginning in the late 1970s. Pakistan first delved into nuclear power after the establishment of its first nuclear power plant near Karachi with equipment and materials supplied mainly by western nations in the early 1970s. Pakistani Prime Minister Zulfiqar Ali Bhutto promised in 1965 that if India built nuclear weapons Pakistan would too, "even if we have to eat grass." It is nearly certain that China only supplied (sold) 5000 critical ring magnets to Pakistan in the early 1980s, and enabled Pakistan to have a rudimentary nuclear weapons capability by the end of the 1980s. The United States continued to certify that Pakistan did not possess nuclear weapons until 1990, when sanctions were imposed under the Pressler Amendment, requiring a cutoff of U.S. economic and military assistance to Pakistan. In 1998, Pakistan conducted its first nuclear tests at the Chagai Hills, in response to the tests conducted by India a few weeks before.

North Korea was a member of the Nuclear Non-Proliferation Treaty, but announced a withdrawal on January 10, 2003 after the United States accused it of having a secret uranium enrichment program and cut off energy assistance under the 1994 Agreed Framework. In February 2005 they claimed to possess functional nuclear weapons, though their lack of a test at the time led many experts to doubt the claim. However, in October 2006, North Korea stated that due to growing intimidation by the USA, it would conduct a nuclear test to confirm its nuclear status. North Korea reported a successful nuclear test on October 9, 2006 (see 2006 North Korean nuclear test). Most U.S. intelligence officials believe that North Korea did, in fact, test a nuclear device due to radioactive isotopes detected by U.S. aircraft; however, most agree that the test was probably only partially successful. The yield may have been less than a kiloton, which is much smaller than the first successful tests of other powers; however, boosted fission weapons may have an unboosted yield in this range, which is sufficient to start deuterium-tritium fusion in the boost gas at the center; the fast neutrons from fusion then ensure a full fission yield. North Korea conducted a second, higher yield test on May 25, 2009 (see 2009 North Korean nuclear test).

Undeclared nuclear states

Israel is not a member of the Nuclear Non-Proliferation Treaty and refuses to officially confirm or deny having a nuclear arsenal, or having developed nuclear weapons, or even having a nuclear weapons program. Israel has pledged not to be the first country to introduce nuclear weapons into the region, but is also pursuing a policy of strategic ambiguity with regard to their possession. In the late 1960s, Israeli Ambassador to the US Yitzhak Rabin informed the United States State Department, that its understanding of "introducing" such weapons meant that they would be tested and publicly declared, while merely possessing the weapons did not constitute "introducing" them. Although Israel claims that the Negev Nuclear Research Center near Dimona is a "research reactor", or, as was originally claimed, a "textile factory," no scientific reports based on work done there have ever been published. Extensive information about the program in Dimona was also disclosed by technician Mordechai Vanunu in 1986.

According to the Natural Resources Defense Council and the Federation of American Scientists, Israel possesses around 75–200 weapons. Imagery analysts can identify weapon bunkers, mobile missile launchers, and launch sites in satellite photographs. Israel may have tested a nuclear weapon along with South Africa in 1979, but this has never been confirmed (see Vela Incident).

On May 26, 2008, former US president Jimmy Carter stated that Israel has “150 or more nuclear warheads” at a press conference at the annual literary Hay festival in Wales.

States alleged to have nuclear weapons programs

Below are countries which have been accused by Israel or the United States of currently attempting to develop nuclear weapons technology.

A U.S. National Intelligence Estimate of December 3, 2007 judged with "high confidence" that Iran had an active nuclear weapons program which was halted in fall 2003 and with "moderate confidence" that it remained halted as of mid-2007. The estimate further judged that US intelligence did not know whether Iran intended "to develop nuclear weapons," but that "Iran probably would be technically capable of producing enough HEU [highly enriched uranium] for a weapon sometime during the 2010-2015 time frame" if it decides to do so. IAEA Director General ElBaradei noted in particular that the Estimate tallies with the Agency's consistent statements over the last few years that "although Iran still needs to clarify some important aspects of its past and present nuclear activities, the Agency has no concrete evidence of an ongoing nuclear weapons program or undeclared nuclear facilities in Iran." Iran's representative to the UN has explained that Iran categorically rejects the development of nuclear weapons and Iran is guaranteed the right to peaceful nuclear technology under the NPT.

On September 6, 2007, Israel bombed an officially unidentified site in Syria which it later asserted was a nuclear reactor under construction (see Operation Orchard). The alleged nuclear reactor was not yet operational and no nuclear material had been introduced into it. Top U.S. intelligence officials claimed low confidence that the site was meant for weapons development, noting that there was no reprocessing facility at the site. Press reports indicated the air strike followed a shipment delivery to Syria by a North Korean freighter, and that North Korea was suspected to be supplying a reactor to Syria for an alleged nuclear weapons program. On October 24, 2007 the Institute for Science and International Security released a report which identified a site next to the Euphrates River in eastern Syria's Deir ez-Zor Governorate province, about 11 kilometers north of the village of At Tibnah, at ), as the suspected reactor. The building appeared to match the external structure of the North Korean 5 megawatt reactor at Yongbyon Nuclear Scientific Research Center, and is surrounded by a security barrier and hidden within a small side canyon off the main river valley. After refusing to comment on the reports for six months, the White House briefed Congress and the IAEA on April 24, 2008, saying that the U.S. Government was "convinced" that Syria had been building a "covert nuclear reactor" that was "not intended for peaceful purposes." Syria denounced "the fabrication and forging of facts" in regards to the incident. IAEA Director General Mohamed ElBaradei criticized the strikes and deplored that information regarding the matter had not been shared with his agency earlier.

A report in the Sydney Morning Herald and Searchina, a Japanese newspaper, report that two Myanmarese defectors saying that the Myanmar junta was secretly building a nuclear reactor and plutonium extraction facility with North Korea's help, with the aim of acquiring its first nuclear bomb in five years. According to the report, "The secret complex, much of it in caves tunnelled into a mountain at Naung Laing in northern Burma, runs parallel to a civilian reactor being built at another site by Russia that both the Russians and Burmese say will be put under international safeguards." In 2002, Myanmar had notified IAEA of its intention to pursue a civilian nuclear programme. Later, Russia announced that it would build a nuclear reactor in Myanmar. There have also been reports that two Pakistani scientists, from the AQ Khan stable, had been dispatched to Myanmar where they had settled down, to help Myanmar's project. Recently, the David Albright-led Institute for Science and International Security rang alarm bells about Myanmar attempting a nuclear project with North Korean help. If true, the full weight of international pressure will be brought against Myanmar, said officials familiar with developments. But equally, the information that has been peddled by the defectors is also "preliminary" and could be used by the west to turn the screws on Myanmar—on democracy and human rights issues—in the run-up to the elections in the country in 2010. During an ASEAN meeting in Thailand in July 2009, US secretary of state Hillary Clinton highlighted concerns of the North Korean link. "We know there are also growing concerns about military cooperation between North Korea and Burma which we take very seriously," Clinton said.

Nuclear weapons sharing

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• , , , , , and historically ,

Under NATO nuclear weapons sharing, the United States has provided nuclear weapons for Belgium, Germany, Italy, the Netherlands, and Turkey to deploy and store. This involves pilots and other staff of the "non-nuclear" NATO states practicing handling and delivering the U.S. nuclear bombs, and adapting non-U.S. warplanes to deliver U.S. nuclear bombs. Until 1984 Canada also received shared nuclear weapons, and until 2001, Greece. Members of the Non-Aligned Movement have called on all countries to "refrain from nuclear sharing for military purposes under any kind of security arrangements." The Institute of Strategic Studies Islamabad (ISSI) has criticized the arrangement for allegedly violating Article I and II of the NPT, arguing that "these Articles do not permit the NWS to delegate the control of their nuclear weapons directly or indirectly to others." NATO has argued that the weapons' sharing is compliant with the NPT because "the U.S. nuclear weapons based in Europe are in the sole possession and under constant and complete custody and control of the United States."

States formerly possessing nuclear weapons

Nuclear weapons have been present in many nations, often as staging grounds under control of other powers. However, in only a few instances have nations given up nuclear weapons after being in control of them; in most cases this has been because of special political circumstances. The fall of the USSR, for example, left several former Soviet-bloc countries in possession of nuclear weapons.

South Africa produced six nuclear weapons in the 1980s, but disassembled them in the early 1990s. In 1979, there was a putative detection of a clandestine nuclear test in the Indian Ocean, and it has long been speculated that it was possibly a test by South Africa, perhaps in collaboration with Israel, though this has never been confirmed (see Vela Incident). South Africa signed the Nuclear Non-Proliferation Treaty in 1991.

Former Soviet countries

• had 81 single warhead missiles stationed on its territory after the Soviet Union collapsed in 1991. They were all transferred to Russia by 1996. Belarus has signed the Nuclear Non-Proliferation Treaty.
• inherited 1,400 nuclear weapons from the Soviet Union, and transferred them all to Russia by 1995. Kazakhstan has signed the Nuclear Non-Proliferation Treaty.
• has signed the Nuclear Non-Proliferation Treaty. Ukraine inherited about 5,000 nuclear weapons when it became independent from the USSR in 1991, making its nuclear arsenal the third-largest in the world. By 1996, Ukraine had voluntarily disposed of all nuclear weapons within its territory, transferring them to Russia.

See also

• Comprehensive Test Ban Treaty
• Nuclear disarmament
• Nuclear Non-Proliferation Treaty
• Nuclear proliferation
• Nuclear war
• Nuclear-Weapon-Free Zone

References

1. "Implementation of the NPT Safeguards Agreement in the Islamic Republic of Iran", IAEA Board of Governors, September 2005.
2. "Implementation of the NPT Safeguards Agreement in the Islamic Republic of Iran", IAEA Board of Governors, February 2006.
3. Webster, Paul (July/August 2003). " Just like old times," Bulletin of the Atomic Scientists 59:4: 30–35.
4. Stephen I. Schwartz, ed., Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940 (Washington, D.C.: Brookings Institution Press, 1998).
5. France 'would use nuclear arms' (BBC, January 2006)
6. John Wilson Lewis and Xue Litai, China Builds the Bomb (Stanford, Calif.: Stanford University Press, 1988). ISBN 0804714525
7. [1][2][3]
8. Norris, Robert S. and Hans M. Kristensen. " Chinese nuclear forces, 2006," Bulletin of the Atomic Scientists 62:3 (May/June 2006): 60-63.
9. Lewis, Jeffery. " The ambiguous arsenal," Bulletin of the Atomic Scientists 61:3 (May/June 2005): 52-59.
10. http://nuclearthreatinitiative.org/db/china/nfuorg.htm
11. Implementation of the India-United States Joint Statement of July 18, 2005: India’s Separation Plan
12. U.S.- India Civil Nuclear Cooperation Initiative – Bilateral Agreement on Peaceful Nuclear Cooperation
13. Statement on Civil Nuclear Cooperation with India
14. Congressional Approval of the U.S.-India Agreement for Cooperation Concerning Peaceful Uses of Nuclear Energy (123 Agreement)
15. Secretary of State Condoleezza Rice and Indian Minister of External Affairs Pranab Mukherjee At the Signing of the U.S.-India Civilian Nuclear Cooperation Agreement
16. Interview With Undersecretary of State for Arms Control and International Security Robert Joseph, Arms Control Today, May 2006.
17. Was India misled by America on nuclear deal?, Indian Express.
18. ACA: Final NSG Statement
19. Norris, Robert S. and Hans M. Kristensen. " India's nuclear forces, 2005," Bulletin of the Atomic Scientists 61:5 (September/October 2005): 73–75.
20. Avner Cohen and William Burr, " The Untold Story of Israel's Bomb," Washington Post, April 30, 2006; B01.
21. Israel's Nuclear Weapons, Federation of American Scientists (August 17, 2000)
22. Iran: Nuclear Intentions and Capabilities (National Intelligence Estimate)
23. Statement by IAEA Director General on New U.S. Intelligence Estimate on Iran (4 December 2007), IAEA.org
24. 6 September 2007 Air strike at globalsecurity.org. Retrieved October 24, 2007.
25. IAEA: Statement by IAEA Director General Mohamed ElBaradei regarding Syria
26. N. Korea, Syria May Be at Work on Nuclear Facility, Glenn Kessler, Washington Post, Thursday, September 13, 2007; Page A12
27. Suspect Reactor Construction Site in Eastern Syria: The site of the September 6 Israeli Raid?, David Albright and Paul Brannan, October 23, 2007
28. Searchina, "Reasons for digging tunnels in Burma", August 11, 2009.
29. "Myanmar building nuke reactor, says media report". The Times of India, 2 August 2009.
30. Statement on behalf of the non-aligned state parties to the Treaty on the Non-Proliferation of Nuclear Weapons, 2 May 2005
31. ISSI - NPT in 2000: Challenges ahead, Zafar Nawaz Jaspal, The Institute of Strategic Studies, Islamabad
32. NATO's Positions Regarding Nuclear Non-Proliferation, Arms Control and Disarmament and Related Issues, NATO, June 2005
33. Nuclear Weapons Program (South Africa), Federation of American Scientists (May 29, 2000).
34. Belarus Special Weapons, Federation of American Scientists
35. Kazakhstan Special Weapons, Federation of American Scientists
36. Ukraine Special Weapons, GlobalSecurity.org
37. Ukraine Special Weapons, Federation of American Scientists

External links

• Archive of Nuclear Data - List of warheads by country
• Nuclear Threat Initiative
• Globalsecurity.org World Special Weapons Guide
• The Nuclear Weapon Archive
• Nuclear Notebook, Bulletin of the Atomic Scientists
• U.S. Nuclear Weapons in Europe: A review of post-Cold War policy, force levels, and war planning NRDC, February 2005
• Pakistani Nuclear Development
• Online NewsHour with Jim Lehrer: Tracking Nuclear Proliferation