NATO's Nuclear Sharing Arrangements

Alisiya Ivanova

Origins and history

The NSA dates back to the early 1950s when the United States began deploying tactical nuclear weapons to Europe as a deterrent against the Soviet Union. The first deployment of U.S. nuclear weapons to Europe occurred in 1954 when the United States delivered gravity bombs to the United Kingdom. In the following years, the U.S. deployed nuclear weapons to other European countries, including Belgium, France, Greece, Italy, the Netherlands, Turkey, and West Germany.

During the Cold War, the NSA was an integral part of NATO's deterrence strategy against the Soviet Union. The number of U.S. nuclear weapons reached its peak in the early 1970s, when it comprised 7,300 weapons. As the tensions between the two competing powers were lowering during the 1980s, various outdated nuclear systems were removed from Europe, while some were decommissioned in compliance with the Intermediate-Range Nuclear Forces (INF) Treaty. It is thought that the total number of nuclear weapons decreased to approximately 4,000.

Few months prior to the official dissolution of the USSR, on 27 September 1991, President George H.W. Bush declared the complete removal of all U.S. tactical ground-launched and naval nuclear weapons from all parts of the world. This involved the elimination of tactical weapons stationed in Europe, in addition to nuclear artillery shells, short-range missile warheads, and naval nuclear depth bombs. Only 1,400 gravity bombs were left in seven European countries following the withdrawal. In 2000, Bill Clinton signed a Directive, which permitted the continued deployment of 480 nuclear bombs in Europe. In the 2000s and 2010s the number of nuclear weapons shared under NSAs was drastically reduced. Most importantly, the START-I treaty, which was in force between the U.S. and Russia from 1994 to 2009, helped to destroy 80% of the world’s stock of strategic nuclear weapons. Also, some European NATO members started to reconsider their approach to nuclear sharing, e.g. Greece withdrew from the Nuclear Sharing Arrangement in 2001, while some nuclear weapon systems were removed from Germany in 2005-2007.

Currently, the NSA involves five non-nuclear NATO countries: Belgium, Germany, Italy, the Netherlands, and Turkey. In 2023, it is estimated that there are around 100 U.S.-owned nuclear weapons deployed in Europe.

NSA’s rationale

NATO justifies the continued existence of the NSA and presence of the nuclear arsenal on the territory of the member-states as a necessary element of its deterrence strategy. NATO suggests that “[t]he fundamental purpose of NATO’s nuclear capability is to preserve peace, prevent coercion and deter aggression”. It is also underlined that since the start of the Russia-Ukraine war, NATO has committed to enhance its nuclear deterrence as well.

Nuclear Sharing Arrangements themselves are seen as a unique way to “demonstrate unity and cohesion amongst all Allies — by sharing both the political burden and operational risks involved with the nuclear deterrence mission.” A special role of the U.S. is also officially recognized, as the nuclear sharing arrangements are thought to be “the most visible expression of the U.S. extended deterrence guarantee for the security of its Allies”.

Alleged Violations of NPT

The main legal problem that arises with the implementation of the Nuclear Sharing Arrangements is its supposed non-conformity with the provisions of the Non-Proliferation Treaty (NPT). The NPT provides that “[e]ach nuclear-weapon State Party to the Treaty undertakes not to transfer to any recipient whatsoever nuclear weapons or other nuclear explosive devices or control over such weapons”, while non-nuclear-weapon states undertake an obligation to not receive nuclear weapons or control over them. While the U.S. is the nuclear-weapon State Party to the treaty, its European allies — Belgium, Germany, Italy, the Netherlands, and Turkey — are parties to the NPT as non-nuclear states.

Naturally, NATO and the U.S. in particular argue that the NSA’s existence is in no way in violation of the Non-Proliferation Treaty. NATO expresses its support for the NPT and non-proliferation as such and maintains that its nuclear sharing program complies with the NPT as the U.S. preserves “absolute control and custody of their nuclear weapons forward deployed in Europe”. In peacetime, all U.S. weapons remain under the custody of U.S. forces — a lawful arrangement under the NPT.

Thus, according to the official stance of the U.S. government, control over all nuclear weapons will remain exclusively in the hands of the United States unless a military conflict arises. Then, the President of the United States can authorize the release of these weapons to foreign governments according to Sections 91 and 92 of the Atomic Energy Act of 1954.

Publicly expressed reasoning for this policy constitutes that the NPT would not be binding if the government decides to “go to war”. It is only natural that in case of a nuclear war hostile powers would not follow their international obligations. However, according to General International Law, international treaties do not cease to be binding in times of military conflict, unless they specifically state so in their text.

Some researchers suggest that since the U.S. has “explicitly stated that once a general war has begun, it would no longer feel bound by the NPT” it has “created a loophole” and would be able to withdraw from the NPT without a due notice in case of war. Nevertheless, the United States' perspective on their responsibilities under the NPT was never officially articulated through any legally recognized means, such as a reservation made at the time of signing the treaty. Thus, there is no clear legal framework under which the U.S. would lawfully transfer control over nuclear weapons to its European allies in the event of war.

NSA in NATO-Russia Relations

The presence of U.S. nuclear weapons in Europe has been a contentious issue since the inception of the NSA, especially in NATO-Russia relations.

The NATO webpage devoted to NATO-Russia relations features Russia’s claim about Nuclear Sharing Arrangements violating the NPT and provides an obvious response: NATO's nuclear arrangements are consistent with International Law, while it is Russia who is not using its nuclear capabilities in a responsible manner.

Indeed, Russia has always perceived NATO Nuclear Sharing Arrangements as unlawful under the NPT, as well as generally undermining strategic stability and international security. However, in 2023 Moscow took a “U-turn” towards nuclear sharing practices. After Putin announced plans to deploy Russia’s tactical nuclear weapons to Belarus, he explained that Russia will exercise full control over the nuclear weapons located in Belarus and underlined that "[...] the United States has been doing this for decades. They have long deployed their tactical nuclear weapons on the territory of their allied countries". Even though nuclear weapons were not yet transeferred to Belarus, by mirroring NATO Nuclear Sharing Arrangements, Russia, in a way, has limited its ability to raise any objections about the deployment of NATO nuclear arsenal in Europe.

Alisiya Ivanova

Junior Analyst, Minsk Dialogue Council on International Relations