The prohibition on assisting, encouraging, or inducing prohibited activities

The 36 states that were engaged in conduct in 2020 that was not compatible with the prohibition on assistance, encouragement, and inducement of prohibited activities are the following:

Albania, Armenia, Australia, Belarus, Belgium, Bulgaria, Canada, Croatia, Czechia, Denmark, Estonia, France, Germany, Greece, Hungary, Iceland, Italy, Japan, Latvia, Lithuania, Luxembourg, Marshall Islands, Montenegro, Netherlands, North Macedonia, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, South Korea, Spain, Turkey, the United Kingdom, and the United States.

They enable other states’ nuclear armament in different ways, discussed under the headings a) to f) below.

a) Participation in nuclear-related military activities with nuclear-armed states

States parties to the TPNW can remain in alliances and military cooperation arrangements with nuclear-armed states, and can continue to execute all operations, exercises, and other military activities together with them in so far as they do not involve nuclear weapons. Participation in ‘nuclear burden-sharing’ and other nuclear-related military activities, however, would need to be discontinued.

Unlike the CWC, the TPNW (and the Anti-Personnel Mine Ban Convention (APMBC) and the Convention on Cluster Munitions (CCM)) does not contain a broad restriction on ‘any military preparations to use’ nuclear weapons. The object and purpose of the TPNW, as well as its negotiating history, leave nothing to suggest that the non-inclusion of a provision on military preparations was meant to exclude such activities from the scope of the Treaty. For the nuclear-armed states themselves, military preparations are generally comprised through the prohibition on possession and stockpiling.

When non-nuclear-armed states participate in such activities together with nuclear- armed states, this is rendered unlawful by the prohibition on assisting or encouraging a prohibited activity. Depending on the context, the prohibited activities that umbrella states typically would assist or encourage through such nuclear-related military cooperation may be development, possession and stockpiling, or threatening to use.

In some cases, it may not be possible to conclude that a specific practice or capability in a given state presently amounts to assistance or encouragement of a prohibited act, while it is clear that it may likely do so in the future. For umbrella states considering which changes they would need to implement in order to ensure compatibility with the TPNW, the central issue is whether maintaining a particular practice or capability would run counter to the object and purpose of the TPNW – which is to ensure that nuclear weapons are never again used under any circumstances and are completely eliminated. Article 5 of the TPNW obligates each state party to take all appropriate legal, administrative and other measures to prevent and suppress prohibited activities undertaken by persons or on territory under its jurisdiction or control, and there is a general obligation under international law to implement the Treaty in good faith.

Under the tabs below follows information on typical nuclear-weapon-related military activities in which today’s umbrella states are known to engage. Given the secrecy surrounding military operations and movements of military material, the Nuclear Weapons Ban Monitor has little information about which and how individual states participated in such activities in 2020, but will continue to research this issue.

b) Endorsement of nuclear-weapons doctrines, policies, and statements

All the member states of NATO (the 27 umbrella states and the 3 nuclear-armed states) act in conflict with Article 1(1)(e) through specific nuclear-related doctrines, policies, and/or statements to which they subscribe. NATO’s foundational document, the North Atlantic Treaty, does not mention nuclear weapons, but every NATO member has supported possession and potential use of nuclear weapons use through their endorsement of various other alliance documents, particularly
the Strategic Concept. None of the alliance’s members have so far rejected the possession or use, or even the first use, of nuclear weapons on its behalf. In the view of the Nuclear Weapons Ban Monitor, this amounts to encouragement of (continued) possession. It does not, however, amount to encouragement of use, as that would require, for instance, a request for use of nuclear weapons in a specific context or agreeing to rules of engagement allowing the use of nuclear weapons in a concrete multinational operation.

Beyond NATO, three states engaged in bilateral defence arrangements with the United States (Australia, Japan, and South Korea) encourage possession through explicit statements they have made or strategy documents they have endorsed. The governments of the United States and Japan expressed through a joint statement in 2013 that they remained committed to the security of Japan ‘through the full range of US military capabilities, including nuclear and conventional’. South Korea has endorsed similar statements. In 2016, Japan and South Korea (together with France and the United Kingdom) reportedly expressed opposition to the Obama administration’s proposal of adopting a nuclear no-first-use policy. With respect to Australia, the most recent example of a government document which appears to directly encourage the United States to retain nuclear weapons was published in 2020, stating that ‘Only the nuclear and conventional capabilities of the United States can offer effective deterrence against the possibility of nuclear threats against Australia.’

In addition to NATO, the Russian-led Collective Security Treaty Organization (CSTO) is understood by certain observers as a nuclear alliance. In 2010, the CSTO’s Secretary-General suggested Russia had extended a ‘nuclear umbrella’ over all members of the alliance. Yet, CSTO members do not appear to have adopted official documents stipulating a nuclear dimension to the alliance. On the contrary, three members have actively distanced themselves from nuclear deterrence. Through the 2006 Treaty of Semipalatinsk – the treaty establishing Central Asia as an NWFZ – Kazakhstan, Kyrgyzstan, and Tajikistan have committed never to ‘assist or encourage’ the development, manufacture, or possession of nuclear weapons.126 Kazakhstan has also signed and ratified the TPNW. Belarus, however, which is allied to Russia through the CSTO and the Union State, has previously expressed public support for nuclear deterrence and is therefore not in compliance with the TPNW’s prohibition on encouragement of possession of nuclear weapons. Armenia, the last CSTO member, has, to our knowledge, not explicitly endorsed the possession and potential use of nuclear weapons on its behalf. Armenia would, though, need to actively distance itself from nuclear deterrence on its behalf in order to be considered compliant with Article 1(1)(e) of the TPNW, as its fellow CSTO members Kazakhstan, Kyrgyzstan, and Tajikistan have already done.

For an overview of arrangements of extended nuclear deterrence, see the table below.

* New Zealand was de facto excluded from ANZUS in the mid-1980s due to its anti-nuclear-weapon policies.

Some of these arrangements are formalised in writing and others are not. They have all emerged as supplements or in parallel to legally binding mutual defence treaties. None of the existing, underlying legally binding mutual defence treaties mentions nuclear weapons specifically. Arrangements of extended nuclear deterrence, or nuclear umbrellas, should therefore be understood as political constructs, not as legally binding obligations. The Norwegian Foreign Minister Ine Søreide confirmed in Parliament in November 2018 that ‘there is no legal obligation barring Norway from signing or ratifying the TPNW, but strong political commitments amounting from the Atlantic Treaty and the strategic documents we have adopted.’

While politically difficult, combining alliance membership and adherence to the TPNW is entirely feasible. Non-nuclear armed members of NATO, for instance, may adhere to the TPNW and remain within the Alliance as long as they explicitly distance themselves from specific statements or formulations in Alliance documents. It could be argued that a NATO member may, without having to explicitly ‘override’ previous endorsement of extended nuclear deterrence, become compliant with the TPNW through the very acts of signing and ratifying the Treaty. However, having adhered to the TPNW, such a state would certainly be obliged to refrain from endorsing future Alliance language supporting the retention and potential use of nuclear weapons.

This could be done either by adjusting the current language or by the state clearly rejecting possession or use of nuclear weapons on its behalf, for instance through ‘footnotes’, an interpretive or declaratory statement, or other unequivocal means of signalling disagreement. NATO members are not obliged to endorse every line of Alliance language. Indeed, there is a tradition of member states ‘footnoting’ or otherwise distancing themselves from specific statements in Alliance documents.

Through their continued endorsement of nuclear-weapons policies and statements, umbrella states contribute to the resolve of nuclear-armed states to modernise and expand their capabilities. Nuclear-armed states often assert a need on behalf of non-nuclear allies and partners to ‘assure’ and fulfil ‘extended deterrence commitments’ as pretexts for their nuclear deployments and modernisation programmes, including new capabilities. For example, the development of the B61-12 nuclear gravity bomb, which will replace the existing B61s stored at six NATO bases in Europe, was necessary – argued the Obama administration – to ‘reassure our nonnuclear allies and partners’. According to the 2009 Report of the Congressional Commission on the Strategic Posture of the United States, America must ‘continue to safeguard the interests of its allies’, including by retaining ‘numbers or types of nuclear capabilities that it might not deem necessary if it were concerned only with its own defense’. The US Mission to NATO in August 2020 stated in a tweet that ‘#NATO needs nuclear weapons because our nuclear deterrent is the ultimate security guarantee for Europe. For 70 years nuclear weapons have kept adversaries at bay & provided reassurance for Allies.’ Some US experts have even described the ability to deter escalation of potential Russian and Chinese conflict with US allies as the ‘primary role’ of US nuclear weapons today.

In the United Kingdom, the national government’s push for a full replacement of the Vanguard-class nuclear ballistic missile submarines in 2016 was based on the argument that NATO was a ‘nuclear alliance’ and that the United Kingdom thereby had no choice but to renew its arsenal of weapons of mass destruction. For the UK prime minister, a failure to build new nuclear submarines would be a ‘reckless gamble’ that would ‘enfeeble’ the United Kingdom’s allies.

In France, President Emmanuel Macron has recently relaunched the idea of a ‘European’ nuclear posture enacted by Paris. Specifically, the President has invited interested European states to take part in a ‘dialogue’ about the French nuclear arsenal’s contribution to European security. Similar initiatives have been made by most French governments since the 1960s, albeit with few takers and little enthusiasm among other European states. According to two scholars, the purpose of the French effort to ‘Europeanise’ its nuclear arsenal is to lend nuclear weapons ‘additional moral justification and legitimacy’ by portraying the French nuclear armoury as ‘an essential constituent of the defence posture of “civilian power Europe”’.

c) Development, production, and maintenance of key components for nuclear weapons – corporate and state responsibility

In a number of states, private companies engage in work that is linked to nuclear weapons. A company that develops, produces, or maintains key components (such as a ballistic missile) for a nuclear weapon or other nuclear explosive device, or which maintains nuclear weapons, would thereby engage the international responsibility of the state in which it is operating under the TPNW. Such a state party would be responsible for prohibited assistance under the Treaty (assistance to development, production, or possession, depending on the acts the company was performing).

Depending on the circumstances, a parent company can also be legally responsible for the acts of its subsidiary. The general position in domestic law is that a parent company is not liable where its subsidiary acts unlawfully. However, jurisprudence has established a number of exceptions to this general principle, allowing the ‘veil of separate legal status … to be pierced’.
Under international law, contravention of the provisions of a disarmament treaty or of customary disarmament law by a corporation would suffice to render the state or states responsible on whose territory that corporation committed the relevant act or acts.

In addition, any company that is engaged in a joint venture that develops or produces key components for a nuclear weapon or other nuclear explosive device could thereby be engaging in prohibited assistance even if it does not itself contribute materially to the nuclear-weapon development or production. This is so wherever a joint venture is akin to a partnership with unlimited liability. It may also occur when the participating companies establish the joint venture as a new body corporate, holding shares in that company. Under international law, the states on the territory of which the participating and shareholding companies are incorporated and/or have their headquarters would be responsible for the acts of the joint venture where those do not comply with an international treaty or customary law on disarmament.

Most companies involved with nuclear weapons are headquartered in the nuclear-armed states, but some have headquarters or divisions in non-nuclear-armed states. The conduct of Belarus, Italy, Germany, and the Netherlands is not compatible with the prohibition on assisting development and manufacturing because they allow companies that are incorporated or have headquarters or production facilities on their territory to be involved in activities that constitute assistance for development and production of nuclear weapons. The Belarusian company Minsk Automobile Plant is the only manufacturer of the mobile launchers for the Russian Topol-M intercontinental ballistic missile (ICBM). The Italian company Leonardo (formerly Finmeccanica) is involved in the design, development, and delivery of Transporter Erector Replacement Vehicles for the US Minuteman III ICBM arsenal.

The multinational company Airbus Group, legally incorporated in the Netherlands and therefore falling under Dutch law and jurisdiction, is currently involved in the development and production of the French Navy’s M51 nuclear-tipped SLBM (but not the warhead) through its German-headquartered subdivision Airbus Defence and Space, which owns 50% of the Ariane Group. All M51 missiles are manufactured and maintained by Ariane Group. The M51 will, over time, represent the main delivery system for France’s strategic nuclear weapons. Since Airbus Group considers that the actions of its subsidiaries form part of the work of Airbus as a group entity, should either Germany or the Netherlands sign and ratify or accede to the TPNW, they would not be compliant with Article 1(1)(e) if Airbus and its subsidiaries were to engage in any further assistance of the development and production of nuclear-capable weapons. The French Air Force’s ASMP-A cruise missiles – designed to deliver nuclear warheads by air – were developed by the joint venture company MDBA, which was made up of Dutch/ German-headquartered Airbus, UK-headquartered BAE Systems, and Italian-headquartered Leonardo.

d) Nuclear cooperation arrangements

The United Kingdom and the United States continue to engage in close cooperation on the Trident SLBM produced in the United States. This amounts to assistance with development and production. The nature of the cooperation on nuclear weapons was first set out in the 1958 Mutual Defense Agreement, a bilateral treaty between the two nations. It has been renewed several times, most recently in 2014 covering the ten years through to 2024. The United Kingdom’s Trident missiles are said to be in a ‘common pool’ shared with the United States and maintained at Kings Bay, in the US state of Georgia.

A cooperation between the United Kingdom and France for the maintenance of nuclear-weapon stockpiles amounts also to prohibited assistance with possession and stockpiling under the TPNW. In June 2018, the Swedish Defence Research Agency reported that the United Kingdom and France were ‘closer to each other than ever on nuclear weapons cooperation’. The two states’ cooperation on nuclear weapons’ issues is supported by the 2010 Teutates Treaty to develop technologies for safe and effective maintenance of both states’ nuclear stockpiles.

US-French cooperation is conducted under a 1961 Mutual Defence Agreement, which permits limited cooperation on the operation of nuclear-weapon systems. Later amendments have enabled enhanced cooperation, notably on issues of safety, security, and reliability.

e) Financing of prohibited activities

The development, production, and maintenance of nuclear weapons constitutes a multi-billion-dollar industry, with numerous large companies and universities profiting from, and lending their legitimacy to, the industrial effort. The TPNW does not explicitly prohibit financing of nuclear-weapon programmes. However, the prohibition on assistance renders unlawful direct funding of any of the prohibited activities listed in the other subparagraphs of Article 1(1). If, for instance, funding in the form of an earmarked loan or a credit line is provided to a company for the development or maintenance of nuclear weapons, this is unlawful assistance with the development or possession of nuclear weapons.

The prohibition on financing encompasses not only state funding, including sovereign funds, but also private banks and individuals, as discussed above in the subsection on corporate and state responsibility. The ordinary purchase of shares in a company involved in the development, production, or maintenance of nuclear arsenals is not per se an illegal act under the TPNW, although ownership could be assessed differently depending on the amount of shares purchased and divestment from such companies is a growing trend.

Cuba issued a declaration upon joining the TPNW, stating that ‘The financing of any activity prohibited to a State Party under this Treaty is also a prohibited activity according to the provisions of Article 1(e)’. The prohibition on assistance also appears in the CCM, where it is widely considered to prohibit financing.

f) Uranium mining and export

Under international law, mining and transfer of uranium is generally lawful, unless it is for the purpose of developing or assisting in the development of a nuclear explosive device. The peaceful use of nuclear energy is protected under Article IV of the NPT, and the Preamble to the TPNW confirms that nothing in the Treaty should be interpreted as affecting that right. A state may therefore extract uranium and either use the nuclear material itself or provide it to another state for peaceful purposes, as long as it is subject to Safeguards Agreements with the International Atomic Energy Agency (IAEA).

Under the TPNW, the provision of uranium to any other state is prohibited where it is not subject to appropriate Safeguards Agreements or if the state party transferring the uranium knows that the material in question will, or is likely to, be used to develop a nuclear weapon or other nuclear explosive device. Otherwise, states parties to the TPNW are permitted to transfer uranium, including to nuclear-armed states and states not party to the TPNW. Several states that mine and export uranium are states parties to the TPNW, including Kazakhstan, Namibia, and South Africa.

Under the NPT, the provision of uranium to any non-nuclear-weapon state is unlawful where it is not subject to appropriate Safeguards Agreements. The NPT does not directly address the legality of provision of uranium to the five nuclear-weapon states designated under that Treaty.

If a state exports uranium to a nuclear-armed state or any other state on the understanding that the uranium would be used exclusively for peaceful purposes, the exporting state could not be considered to be in violation of either the TPNW or the NPT if the importing state unexpectedly decided to use the uranium for weapons development instead. This would, though, be likely to affect the legality of future exports of uranium to that state.

When armed groups control areas of a state’s territory or when an armed conflict is ongoing, situations could occur where it would be difficult for the authorities of a state in which uranium deposits exist to effectively control all extraction and transfers. If a non-state actor in such a situation were to transfer uranium to an actor intending to develop a nuclear explosive device, the territorial state could not be considered to be in violation of either the TPNW or the NPT, provided that it has made all reasonable efforts to prevent such extraction and transfers. All reasonable efforts would include the adoption of national legislation and implementation of other practical measures, to secure as far as possible sites in which uranium is present or where stocks of uranium are held.