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, and in particular provides for the armed forces of these countries to be involved in delivering these weapons in the event of their use.
As part of nuclear sharing, the participating countries carry out consultations and take common decisions on nuclear weapons policy, maintain technical equipment required for the use of nuclear weapons (including warplanes capable of delivering them), and store nuclear weapons on their territory. In case of war, the United States told NATO allies the Non-Proliferation Treaty (NPT) would no longer be controlling.
Of the three nuclear powers in NATO (France, the United Kingdom and the United States), only the United States is known to have provided weapons for nuclear sharing. As of November 2009[update], Belgium, Germany, Italy, the Netherlands and Turkey are still hosting U.S. nuclear weapons as part of NATO's nuclear sharing policy. Canada hosted weapons until 1984, and Greece until 2001. The United Kingdom also received U.S. tactical nuclear weapons such as nuclear artillery and Lance missiles until 1992, despite the UK being a nuclear weapons state in its own right; these were mainly deployed in Germany.
In peace time, the nuclear weapons stored in non-nuclear countries are guarded by U.S. airmen though previously some artillery and missile systems were guarded by US Army soldiers; the Permissive Action Link codes required for arming them remain under American control. In case of war, the weapons are to be mounted on the participating countries' warplanes. The weapons are under custody and control of USAF Munitions Support Squadrons co-located on NATO main operating bases who work together with the host nation forces.
As of 2005[update], 180 tactical B61 nuclear bombs of the 480 U.S. nuclear weapons believed to be deployed in Europe fall under the nuclear sharing arrangement. The weapons are stored within a vault in hardened aircraft shelters, using the USAF WS3 Weapon Storage and Security System. The delivery warplanes used are F-16s and Panavia Tornados.
Historically, the shared nuclear weapon delivery systems were not restricted to bombs. Greece used Nike-Hercules Missiles as well as A-7 Corsair II attack aircraft. Canada had Bomarc nuclear-armed anti-aircraft missiles, Honest John surface-to-surface missiles and the AIR-2 Genie nuclear-armed air-to-air rocket, as well as tactical nuclear bombs for the CF-104 fighter. PGM-19 Jupiter medium range ballistic missiles were shared with Italian air force units and Turkish units with US dual key systems to enable the warheads. PGM-17 Thor intermediate range ballistic missiles were forward deployed to the UK with RAF crews. An extended version of nuclear sharing, the NATO Multilateral Force was a plan to equip NATO surface ships of the member states with UGM-27 Polaris missiles, but the UK ended up purchasing the Polaris missiles and using its own warheads, and the plan to equip NATO surface ships was abandoned.
The only German nuclear base is located in Büchel Air Base, near the border with Luxembourg. The base has 11 Protective Aircraft Shelters (PAS) equipped with WS3 Vaults for storage of nuclear weapons (maximum capacity of 44). There are 20 B61 nuclear bombs stored on the base for delivery by German PA-200 Tornado IDS bombers of the JaBoG 33 squadron. By 2015 Germany's Tornado IDS aircraft were due to be retired, and it is unclear what nuclear sharing role, if any, Germany will then retain.
In Italy around 40 B61 nuclear bombs (types 3, 4 and 10) are stored in Ghedi Air Base. They can be delivered by the Panavia Tornado IDS bombers of the 6th wing. The former Italian President Francesco Cossiga acknowledged the presence of U.S. nuclear weapons in Italy, and speculated about the possible presence of British and French nuclear weapons.
According to the press, Eastern European Member States of NATO have resisted the withdrawal of the shared nuclear bombs from Europe, fearing it would show a weakening of US commitment to defend Europe against Russia.
Saudi Arabian-Pakistani Agreement
Officials in the West believe Saudi Arabia and Pakistan have an understanding in which Islamabad would supply the kingdom with warheads if security in the Persian Gulf was threatened. A Western official told The Times that Riyadh could have the nuclear warheads in a matter of days of approaching Islamabad. Pakistan's ambassador to Saudi Arabia, Mohammed Naeem Khan was quoted as saying that "Pakistan considers the security of Saudi Arabia not just as a diplomatic or an internal matter but as a personal matter." Naeem also said that the Saudi leadership considered Pakistan and Saudi Arabia to be one country. Any threats to Saudi Arabia is also a threat to Pakistan. Other vendors were also likely to enter into a bidding war if Riyadh indicated that it was seeking nuclear warheads. Both Saudi Arabia and Pakistan have denied the existence of any such agreement. Western intelligence sources have told The Guardian that the Saudi monarchy has paid for up to 60% of the cost of Pakistan's atomic bomb projects and in return has the option to buy five to six nuclear warheads off the shelf. Saudi Arabia has potential dual purpose delivery infrastructure including Tornado IDS and F-15S fighter bombers and improved Chinese CSS-2 intermediate range ballistic missiles with accuracy sufficient for nuclear warheads but delivered with high explosive warheads. 
In November 2013, a variety of sources told BBC Newsnight that Saudi Arabia had invested in Pakistani nuclear weapons projects and believes it could obtain nuclear bombs at will. Earlier in the year, a senior NATO decision maker told Mark Urban, a senior diplomatic and defense editor, that he had seen intelligence reporting that nuclear weapons made in Pakistan on behalf of Saudi Arabia are now sitting ready for delivery. In October 2013, Amos Yadlin, a former head of Israeli military intelligence, told a conference in Sweden that if Iran got the bomb, "the Saudis will not wait one month. They already paid for the bomb, they will go to Pakistan and bring what they need to bring." Since 2009, when King Abdullah of Saudi Arabia warned visiting US special envoy to the Middle East Dennis Ross that if Iran crossed the threshold, "we will get nuclear weapons", the kingdom has sent the Americans numerous signals of its intentions. Gary Samore, who until March 2013 was President Barack Obama's counter-proliferation adviser, told BBC Newsnight: "I do think that the Saudis believe that they have some understanding with Pakistan that, in extremis, they would have claim to acquire nuclear weapons from Pakistan."
According to the US based think-tank, the Center for Strategic and International Studies, the BBC report on possible nuclear sharing between Pakistan and Saudi Arabia is partially incorrect. There is no indication of the validity or credibility of the BBC’s sources, nor does the article expand on what essentially constitutes an unverified lead. Furthermore, if Pakistan were to transfer nuclear warheads onto Saudi soil, it is highly unlikely that either nation would face any international repercussions if both nations were to follow strict nuclear sharing guidelines similar to that of NATO. A research paper produced by the British House of Commons Defence Select Committee states that as long as current NATO nuclear sharing arrangements remain in place, NATO states would have few valid grounds for complaint if such a transfer were to occur.
Nuclear Non-Proliferation Treaty considerations
Both the Non-Aligned Movement and critics inside NATO believe that NATO's nuclear sharing violates Articles I and II of the Nuclear Non-Proliferation Treaty (NPT), which prohibit the transfer and acceptance, respectively, of direct or indirect control over nuclear weapons.
The US insists that its forces control the weapons, and that no transfer of the nuclear bombs or control over them is intended "unless and until a decision were made to go to war, at which the NPT would no longer be controlling", so there is no breach of the NPT. However, the pilots and other staff of the "non-nuclear" NATO countries practice handling and delivering the US nuclear bombs, and non-US warplanes have been adapted to deliver US nuclear bombs which involved the transfer of some technical nuclear weapons information. Even if the US argument is considered legally correct, some[who?] argue such peacetime operations appear to contravene both the objective and the spirit of the NPT. Essentially, all preparations for waging nuclear war have already been made by supposedly non-nuclear weapon states.
At the time the NPT was being negotiated, the NATO nuclear sharing agreements were secret. These agreements were disclosed to some of the states, including the Soviet Union, negotiating the treaty along with the NATO arguments for not treating them as proliferation. Most of the states that signed the NPT in 1968 would not have known about these agreements and interpretations at that time.
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