The prohibition on assistance, encouragement, or inducement
The prohibition on assistance, encouragement, or inducement of prohibited activities is the provision of the TPNW that is contravened by the greatest number of states. A total of 38 states—all states not party to the TPNW—aided and abetted other states’ nuclear-weapons programmes in 2022. This was two more than in the previous year, with Finland and Sweden as the new states.


Each State Party undertakes never under any circumstances to: ‘Assist, encourage or induce, in any way, anyone to engage in any activity prohibited to a State Party under this Treaty.’
- Under this provision, a state party is precluded from assisting any other state, alliance, or international organisation, company, non-state actor, or individual to develop, test, produce, manufacture, otherwise acquire, possess, stockpile, transfer, deploy, receive, threaten to use, or use nuclear weapons or other nuclear explosive devices.
- States parties to the TPNW are allowed to participate in security alliances and military cooperation arrangements with nuclear-armed states—and may continue to carry out all planning, operations, exercises, and other military activities with them—so long as this does not involve nuclear weapons. Participation in nuclear-weapon-related military activities, however, would need to be discontinued.
- Other disarmament treaties contain a similarly worded prohibition, and there is an established understanding in international law of the concepts of assistance, encouragement, and inducement.
- Conduct by omission as well as act is covered by the prohibition. This is so, irrespective of the inclusion of the words ‘in any way’.
- The effects of violating this prohibition are identical, regardless of which alternative has been violated. If an act is clearly assistance, it is not necessary to determine whether the act also constitutes encouragement, and vice versa.
ASSISTANCE
- In order for conduct to constitute assistance, there must be a causal link between the conduct and a prohibited activity. In addition, the conduct must contribute significantly to this activity, although it does not need to be essential to its occurrence. Insignificant contributions would not constitute prohibited assistance. Inherent in the requirement that the contribution is significant is that the prohibited activity which is assisted must be ongoing or temporally proximate. This means that while the prohibited activity need not have happened or be ongoing, it cannot be only a theoretical possibility.
- The state must have acted with the knowledge that the conduct would, in the ordinary course of events, assist a prohibited activity. This effectively excludes temporally remote or incidental contributions.
- The forms of assistance that are unlawful can be, among others, financial (such as through economic assistance for nuclear-weapon production); technological (for example, by the export of equipment/components for such production); operational (for instance, by conventional military support for nuclear bombing); technical (through the provision of expert information); or human (such as by seconding nuclear scientists to assist in another state’s nuclear-weapons programme).
ENCOURAGEMENT
- ‘Encouraging’ in the context of the TPNW means persuading or seeking to persuade any other state or any legal or natural person to carry out a prohibited activity or continue an ongoing violation of any of the other Article 1 prohibitions.
- The prohibited activity being encouraged does not need to materialise as it is the act of encouragement that is prohibited and not the result.
- Encouragement could take the form of verbal, written, material, or institutional support, whether from a government as such (for instance, through the adoption of a particular policy or document) or from pertinent senior government or military officials. Where such support has been given, the encouragement is understood to be ongoing until the point at which it is clearly withdrawn.
INDUCEMENT
- Inducing a prohibited activity means offering someone something in exchange for the performance of that activity. Thus, inducing will always involve encouragement.
Of the 38 states not party that in 2022 engaged in conduct that was not compatible with Article 1(1)(e) of the TPNW (see the full list above), three—France, the United Kingdom, and the United States—are nuclear-armed while the remainder are non-nuclear-armed (and mostly European). They assisted development, production, or possession of nuclear weapons in multiple ways, as discussed under the headings below. Given the secrecy surrounding military activities, the information is likely incomplete.
Participation in nuclear strike exercises

In October 2022, Belgium, Germany, Italy, the Netherlands, and Türkiye, along with a number of other unidentified non-nuclear-armed North Atlantic Treaty Organization (NATO) states, acted in conflict with Article 1(1)(e) when, together with the United States, they took part in the nuclear strike exercise ‘Steadfast Noon’.1 In recent years, Czechia and Poland have also taken part in the annual exercise, which simulates the use of nuclear weapons. Norwegian authorities explained in 2022 that Norway would not take part in the drill and never had. Specifically, the participating states’ involvement in the exercise amounted to encouragement of US possession and development of nuclear weapons. After all, practising nuclear-weapon use implies an endorsement of the potential use of the weapons in the future and, by extension, an encouragement of the possession of nuclear weapons in the present. Nuclear-weapon-use exercises are frequently conducted precisely with a view to building collective resolve and commitment to continued possession as well as for potential use of nuclear arms in certain circumstances.
The drill, which in 2022 was centred at Kleine Brogel Airbase in Belgium, allows NATO members to practise for the use of the B61 nuclear bombs stationed in Europe. The nuclear weapon host states Belgium, Germany, Italy, and the Netherlands practised the loading of dummy B61 nuclear bombs onto their dual-capable aircraft and simulated use, and the other states likely practised air-cover manoeuvres using conventional fighter aircraft.
The year 2022 also saw a number of joint manoeuvres between conventional fighter planes or other military capabilities of non-nuclear-armed states and US or Russian strategic bombers. While these joint manoeuvres were not necessarily in direct conflict with the Article 1(1)(e) of the TPNW, they nevertheless cast nuclear shadows over the participation of non-nuclear-armed states. For example, in August 2022, Norwegian and Swedish warplanes took part in manoeuvres with an American nuclear-capable B-52 bomber over Northern Norway.2 Another example is when Russian strategic bombers flew repeated patrols over Belarus, engaging in military exercises with Belarusian forces.3
The dual capability of most strategic bombers renders unequivocal legal assessment of such participation difficult. Provided that the manoeuvres in question are not specifically ‘nuclear’, i.e. that the deployed nuclear-capable bombers are not practising for the use of nuclear weapons but are instead involved in conventional-weapon roles, participation by non-nuclear-armed states is not unlawful under the TPNW. That said, the deployment of strategic bombers often has a clear nuclear ‘signalling’ effect. In most cases, information about the true nature of such manoeuvres (and the roles of the various non-nuclear-armed states involved) is not available.
Logistical and technical support
The five nuclear host states—Belgium, Germany, Italy, the Netherlands, and Türkiye—continued in 2022 to provide logistical and security services at the bases where US nuclear weapons are deployed to their territory. This constitutes assistance with possession and stockpiling of nuclear weapons under the TPNW. (Of course, these five states are also acting in conflict with Article 1(1)(g), which explicitly prohibits the hosting of another state’s nuclear weapons.)
The Nuclear Weapons Ban Monitor has not found evidence that other non-nuclear-armed states provided logistical and technical support in 2022 that would contravene the TPNW, but lack of transparency prevents a full picture. The provision of logistical and technical support to, for instance, a submarine specifically designed to carry nuclear weapons, would likely constitute assistance with possession of the weapons, provided that the support is a significant contribution. Port visits by ballistic missile submarines (SSBNs) are rare, however, as such submarines typically seek to remain undetected and untraceable while on patrol. It is particularly rare that they visit non-nuclear-armed states.
The United Kingdom provided logistical and technical support to the United States when US nuclear-armed submarines made port visits in 2022 to UK territory. In July, a US SSBN visited the United Kingdom’s naval base at Faslane in Scotland. In October 2022, a US SSBN docked for several days at the island of Diego Garcia, an overseas territory of the United Kingdom in the Indian Ocean used by the United States as a naval and air base. Finally, in early November, a US SSBN also made a short stop in Gibraltar.
In the case of logistical and technical support for dual-use delivery vehicles, such as bombers or fighter-bombers, there will normally be no presumption of nuclear involvement. It will therefore be generally legally unproblematic for states parties to the TPNW that are allies and partners of nuclear-armed states to continue to host or provide logistical and technical support to those states’ dual-use delivery vehicles. For instance, Russian dual-capable bombers and fighters were hosted in Belarus during 2022. In Australia, plans were put in motion in 2022 to upgrade Tindal airbase in the Northern Territory. The upgrade will be funded by the United States and will allow the base to house up to six B-52 bombers at a time.4 There is no evidence that the aircraft in question were or will be specifically engaged or deployed in nuclear roles. If, however, the purpose of a mission or presence with a nuclear-armed state’s dual-use delivery vehicle is clearly nuclear, the provision of logistical or technical support is likely to contravene the prohibition on assistance to, or encouragement of, prohibited activities.
Intelligence gathering and sharing
If a state party to the TPNW were to share intelligence with a nuclear-armed state in the knowledge that it would be used to identify targets for a temporally proximate use or threat to use nuclear weapons, this would amount to assisting use or threatening to use nuclear weapons.
Norway, for example, plays an important role in intelligence gathering, including the observing of the movement of nuclear-armed Russian submarines in the Arctic. Sharing such information in the knowledge that it would be used for nuclear targeting in a proximate attack would amount to unlawful assistance under the TPNW. Another example is Pine Gap, an intelligence facility built and funded by the United States outside Alice Springs in Australia and operated by the US National Reconnaissance Office. More than 800 Australian and US personnel staff the facility, including members of units from all four branches of the US military. One of the components of the facility is a Relay Ground Station in Pine Gap’s western compound, whose Overhead Persistent Infra-Red (OPIR) sensors will detect the heat bloom of any intercontinental or submarine-launched ballistic missiles launched against the United States. It provides early warning of an incoming attack but also indicates whether a nuclear missile launch site/launcher is empty (following firing) or not.5
If Australia were to adhere to the TPNW and the Relay Ground Station were nevertheless used to identify imminent targets for US nuclear weapons, this would violate the prohibition on assisting use or the threatening of use. (This would not be the case if the data were used to identify targets for conventional strikes or to alert a vulnerable target population.) Since such future use or threat to use nuclear weapons remains a theoretical possibility, the operations of the Relay Ground Station do not presently constitute assistance or encouragement to use or threaten to use nuclear weapons.
In so far as it applies to nuclear weapons, however, the current arrangement with the Australian government at Pine Gap is part of the United States’ nuclear-strategic infrastructure and can thus be considered a manifestation of Australia’s encouragement of continued US possession of such weapons. Maintaining a capability and preparedness to identify targets for nuclear strikes also runs counter to the object and purpose of the TPNW. To ensure compatibility with the TPNW, Australia should provide assurances that the Relay Ground Station’s OPIR systems will not be used for nuclear targeting.
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 under the TPNW, while it is clear that it may well 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. (See TPNW preambular paragraph 2.)
Article 5 of the TPNW also 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. There is a general obligation under international law to implement in good faith every treaty to which a State adheres.
Participation in nuclear planning
With the exception of France, all NATO allies are members of the NATO’s Nuclear Planning Group (NPG), the alliance’s senior body on nuclear strategy. Their participation in nuclear strike planning entails an endorsement of the potential use of nuclear weapons in the future and thus an encouragement of the possession and development of nuclear weapons in the present. Participation in planning of temporally proximate use or threats to use nuclear weapons would amount to prohibited assistance for use or the threatening of use.
Japan and South Korea are engaged in ‘extended deterrence dialogues’ with the United States, covering conventional as well as nuclear deterrence. Japan and the United States met for an extended deterrence dialogue in Japan in November 2022.13 South Korea, for its part, reportedly ‘reactivated’ its extended deterrence dialogue in 2022 after a few years without actual meetings.
Any assessment of the compatibility with the TPNW of Japan’s and South Korea’s participation in extended deterrence dialogues is largely context-dependent. To the extent that such dialogue is on general nuclear deterrence where future use is theoretical, Japan and South Korea’s participation should be considered as encouragement of possession of nuclear weapons. To the extent that the nuclear-related dialogue concerns specific targets and is directed and communicated towards a specific adversary, it could also amount to assistance to threatening to use nuclear weapons.
If Japan and South Korea were to adhere to the TPNW in the future, they would have to provide assurances that their respective ‘extended deterrence dialogues’ with the United States would not involve nuclear planning.
Allowing the testing of missiles designed to carry nuclear warheads

The Marshall Islands, which is undecided on the TPNW, is the only non-nuclear-armed state that in 2022 permitted the testing of missiles designed to carry nuclear warheads on its territory. Allowing such testing is not consistent with the TPNW’s prohibition on assistance with development of nuclear weapons. The Marshall Islands hosts a test site that regularly serves as the destination point for US test launches of nuclear-capable long-range missiles. The site in question is the Ronald Reagan range at Kwajalein Atoll, a military station established after the Second World War. The land on which the site is located is leased to the United States through a long-term agreement. It is not the testing site in and of itself that conflicts with the TPNW, but the United States’ use of it to maintain and develop nuclear-weapon missile technology.
Having initially postponed such tests due to the risk of escalation associated with the Russian invasion of Ukraine, the United States launched Minuteman intercontinental ballistic missiles from Vandenberg Air Force Base in California to Kwajalein Atoll in August and September 2022. Should the Marshall Islands decide to adhere to the TPNW, such testing would need to stop if it involved nuclear-capable missiles. Marshallese adherence to the TPNW could thus lead to friction with the United States, perhaps helping to explain the Marshall Islands’ hesitancy about joining the Treaty. With its long history as a testing ground for US nuclear weapons, the Marshall Islands has been a strong supporter of nuclear disarmament and the campaign to end nuclear testing.
Also Kazakhstan, which is a state party to the TPNW, hosts a test site which has previously been the destination for test launches of nuclear-capable long-range missiles. The Sary-Shagan missile range was established by the Soviet government in 1956. There is no evidence that Russia used the Sary-Shagan site to test missiles designed to carry nuclear warheads in 2022. Sary-Shagan appears not to have been used as the destination point for intercontinental ballistic missile tests for some time now, possibly in reaction to Kazakhstan’s ratification of the TPNW. In fact, Russian officials have noted the problem of not having testing grounds on Russian soil, and Russia has begun constructing a new missile test site on Russian territory.6 That said, Russia announced in 2022 that it planned to launch missiles from the Kaputsin Yar range in Russia in 2023. Missiles launched from Kaputsin Yar have traditionally landed at the Sary-Shagan site.7
As a state committed to the goals of the TPNW and the Central Asian Nuclear-Weapon-Free Zone (NWFZ) treaty, Kazakhstan should communicate its priorities to Russia and request that it continues to abstain from using the Sary-Shagan site to test any missiles designed to carry nuclear warheads (unless the sole purpose is to test the conventional capability of dual-capable missiles).
It has been suggested that the obligation in TPNW Article 4(2) to ensure ‘the elimination or irreversible conversion of all nuclear-weapons-related facilities’ obligates Kazakhstan to close the Sary-Shagan site. However, Article 4(2) applies to any state that ‘owns, possesses or controls nuclear weapons or other nuclear explosive devices’ and can therefore not be applied to Kazakhstan. To the extent that Sary-Shagan is ‘clearly connected to Russia’s nuclear weapon complex’, any responsibility to eliminate or irreversibly convert the Sary-Shagan test site under Article 4(2) would fall on Russia.
Endorsement of nuclear-weapons doctrines, policies, and statements

A total of 34 non-nuclear-armed states contravened Article 1(1)(e) of the TPNW in 2022 through specific nuclear-related doctrines, policies, and/or statements to which they subscribe. This concerns the 27 umbrella states in NATO; prospective NATO members Finland and Sweden; US allies Australia, Japan, and South Korea; and Russian allies Armenia and Belarus.
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 through their endorsement of various other alliance documents, particularly the Strategic Concept, which was last updated in 2022.8 None of the alliance’s members has so far rejected the possession or use—or even the first use—of nuclear weapons on its behalf. In the view of the Ban Monitor, their endorsement of the Strategic Concept amounts to encouragement of possession of nuclear weapons. 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.
Two prospective NATO members, Sweden and Finland, submitted letters of intent in 2022 where they declared that they accept ‘NATO’s approach to security and defence, including the essential role of nuclear weapons’ and that they are ‘willing to commit forces and capabilities for the full range of Alliance missions.’9 These documents, and several public statements in support of nuclear weapons by the governments of Sweden and Finland, are inconsistent with the TPNW’s Article 1(1)(e) as they encourage the possession of nuclear weapons by NATO members.22
Three non-NATO US allies (Australia, Japan, and South Korea) also encourage possession of nuclear weapons through explicit statements they have made or strategy documents they have endorsed. 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.’10
In addition to NATO, the Russian-led Collective Security Treaty Organization (CSTO) is understood by some 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.11 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. As noted above, Kazakhstan is also a state party to the TPNW.
Belarus, however, which is allied to Russia through the CSTO and the Union State, has on multiple occasions expressed support for nuclear deterrence (including through requests to host Russian nuclear weapons on Belarusian soil) 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 the Ban Monitor’s 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 in order to be considered compliant with Article 1(1)(e) of the TPNW, as fellow CSTO members Kazakhstan, Kyrgyzstan, and Tajikistan have already done through their adherence to the Treaty of Semipalatinsk, and in Kazakhstan’s case also to the TPNW.
Through their continued endorsement of nuclear deterrence, umbrella states contribute to the resolve of nuclear-armed states continuously to rebuild and maintain their nuclear 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 the building of new capabilities
- Non-nuclear-armed states may adhere to the TPNW and remain within an alliance with one or more nuclear-armed states as long as they explicitly distance themselves from specific statements or formulations in alliance documents that amount to encouragement of use or possession of nuclear arms.
- It could be argued that, for example, a NATO member may, without having to explicitly ‘override’ previous endorsement of extended nuclear deterrence, become compliant with the TPNW through the acts of signing and ratifying the Treaty. However, having adhered to the TPNW, such a state would be obliged to refrain from endorsing future NATO 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 means of signalling disagreement with any endorsement of the potential use or possession of nuclear weapons.
- Such footnotes or statements could be simple and for instance phrased as follows: ‘State X does not support the possession or use of nuclear weapons or other nuclear explosive devices on its behalf and will not assist the development, possession, acquisition, or use of such weapons or devices in any way.’
- 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.
Development, production, and maintenance of key components for nuclear weapons

The conduct in 2022 of umbrella states Belarus, Germany, Italy, and the Netherlands was not compatible with the TPNW’s prohibition on assistance, because they allow companies within their jurisdiction to be involved in development, production and maintenance of key components for nuclear weapons.
Belarus continued to assist Russia with development and production of nuclear weapons, through two Belarusian companies that provide launch capability for the Russian Topol-M intercontinental ballistic missile. The Minsk Automobile Plant manufactures the mobile launchers and Volat (Minsk Wheel Tractor Plant Joint Stock Company) designed, and continues to produce, the MAZ-7917 specialised chassis system to carry the Topol missiles.
Germany and the Netherlands continued to assist France with development, production, and possession of nuclear weapons, as a result of Airbus Defence and Space’s activities in the joint venture companies MBDA and ArianeGroup. MBDA produces France’s current nuclear-tipped ASMPA air-launched cruise missiles and takes part in the production of the next generation of longer-range ASN4G nuclear-tipped air-launched cruise missiles. ArianeGroup is the lead contractor for the ongoing maintenance and the modernisation of France’s M51 nuclear-armed submarine-launched ballistic missiles. The international responsibility of Germany is engaged because Airbus Defence and Space is headquartered in Germany. The international responsibility of the Netherlands is engaged because Airbus Defence and Space’s parent company Airbus, which considers that the work done by its subsidiaries is indivisible from the group, is headquartered in the Netherlands.
Italy continued to assist France with the development and production of nuclear weapons, because it allows the Italian company Leonardo (formerly Finmeccanica) to be involved in the abovementioned joint venture MBDA.
- 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. Such a state party would be responsible for prohibited assistance under the TPNW (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 subsidiaries. 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 company establishes a new body corporate, and is 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 or any involved divisions, departments, or production facilities would be responsible for the acts of the joint venture where those do not comply with an international treaty or customary law on disarmament.
Ownership in and other financial assistance to the nuclear-arms industry
The conduct in 2022 of umbrella states Belarus, Italy, Germany, and Spain was not compatible with the TPNW’s prohibition on assistance because of their significant ownership shares in companies involved in the development, production, and maintenance of nuclear weapons.
Belarus
Belarus owns 100% of the two companies Minsk Automobile Plant and Volat, which as discussed above produce key components for Russia’s nuclear weapons.
Germany and Spain
The German state and the Spanish state both have significant ownership shares in Airbus,35 which in turn through Airbus Defence and Space has significant ownership shares in the joint venture companies MBDA and ArianeGroup.36 As discussed in the section above, MBDA and Ariane Group develop, produce, and maintain key components for France’s nuclear weapons.
Italy
Italy has a significant ownership share in Leonardo (formerly Finmeccanica), which in turn has a significant ownership share in the above-mentioned joint venture, MBDA.
More research is needed on direct state ownership in companies involved in the nuclear-arms enterprise. Such ownership appears to exist only for nuclear-armed states and certain umbrella states. In terms of private financial institutions’ shareholding in and other financial assistance to the nuclear-arms industry it is similarly in the nuclear-armed states and umbrella states that we see the most activity.
According to the 2022 Pax/ICAN Don’t Bank on the Bomb report, ‘Risky Returns’, 306 financial institutions based in 26 states made over US$746 billion available to the 24 companies most heavily involved in the production of nuclear weapons in nuclear-armed states between January 2020 and July 2022.12 This funding was made available through shareholding and debt financing in the form of bondholding, loans, and underwriting. Looking more closely at its findings for the Ban Monitor, Pax/ICAN found that 72 of the financial institutions which held shares or bonds or had loans or underwriting in effect in 2022 were headquartered in 18 non-nuclear-armed states (listed in the table below). They are mostly umbrella states, with Canada and Japan standing out as the non-nuclear-armed states with the most financial involvement in the nuclear-arms industry, closely followed by Australia and Germany. The table also includes the following states with nuclear-weapons-free security policies: Bahrain, Saudi Arabia, Switzerland, and the United Arab Emirates, and one state party to the TPNW – South Africa.
Only two of the 72 investors in non-nuclear-armed states had ownership shares above 3% in an individual company involved in the nuclear-arms industry, and it is the Ban Monitor’s assessment that neither of the two had significant ownership shares: the Canadian investor Sunlife Financing had a 3.2% share in the US company Northrop Grumman, while the Japanese investor Orix Corporation had a 3.2% ownership share in the US company Leidos and another 3.2% ownership share in the US company Textron.
The South African investor NinetyOne held a smaller number of shares in Jacobs Engineering, which is involved in US and UK nuclear-weapon modernisation efforts, through a UK registered subsidiary. Also in South Africa, Standard Bank had an outstanding loan for general corporate purposes to Fluor, which produces tritium for the US nuclear arsenal. Because the ownership share of NinetyOne was small, and because Standard Bank’s loan to Fluor was for general corporate purposes and not linked to the nuclear-related activities of Fluor, the international responsibility of South Africa is not formally engaged under the TPNW’s prohibition on assistance. It is clear, however, that any ownership of and any financial support to companies involved in the nuclear-arms industry to some degree will facilitate such activities. There is, for instance, no guarantee that a loan issued for ‘general corporate purposes’ is not in effect being applied to support a nuclear-weapons related project.
The Ban Monitor therefore calls upon all states parties to the TPNW to take action to prevent and suppress any ownership of and financial assistance to the nuclear-arms industry and adopt clear national guidance embedded in domestic law for financial sector actors, whether public or private. Financial institutions benefit from guidance provided by governments on the ways to interpret norms and international law. At the First Meeting of States Parties to the TPNW (1MSP) in June 2022, a group of 37 financial institutions called on the TPNW membership to provide this clarity and oversight.42 In their statement, they said: ‘It would be illogical to prohibit the production of nuclear weapons without prohibiting the financing that enables the production to proceed. Financing gives life to the production process.’13
Since 2021, the year the TPNW entered into force, Don’t Bank on the Bomb reports that as many as 139 financial institutions ended financial support to companies involved in the nuclear-weapons business, including 55 new institutions in 2022.14 Several of these institutions cited the TPNW in their exclusion policies, or in reports to the press asking about their divestment activities.
- All investment in the nuclear-arms enterprise runs counter to the object and purpose of the TPNW — which is to ensure that nuclear weapons are never again used under any circumstances.
- The TPNW does not explicitly prohibit the financing of nuclear-weapon programmes. The ordinary purchase of shares in a company involved in the development, production, or maintenance of nuclear arsenals is therefore not per se an illegal act under the TPNW. The prohibition on assistance in Article (1)(e), however, renders unlawful any significant and especially any controlling shareholding in a company involved in the development, production, or maintenance of nuclear weapons.
- It is not possible to define as a matter of international law what constitutes a significant ownership share in terms of a fixed percentage of shares or votes that applies consistently across every state, as this varies from country to country and market to market, and differs based on the type of company. To determine if a specific shareholder has significant influence on the management of a company, it is necessary to assess the ownership profile of the relevant company and applicable national law.
- The prohibition on assistance also renders unlawful direct funding of any of the prohibited activities listed in other subparagraphs of Article 1(1). If, for instance, financing in the form of an earmarked loan or credit line is provided to a company for the development, production, or maintenance of nuclear weapons, this is unlawful assistance with the development, production, and possession of nuclear weapons.
- • The prohibition on assistance encompasses not only state funding, but also private banks and other financial institutions as well as individuals.
- 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).’ (See: https://bit.ly/3eB7UMm.
Cooperation between nuclear-armed states

The United Kingdom and France are engaged in close cooperation on technology related to weapons renewal and maintenance of the two countries nuclear stockpiles, which amounts to prohibited (mutual) assistance with both development of nuclear weapons and possession and stockpiling under the TPNW. The France-UK Teutates Programme comprises a joint testing facility called EPURE in Valduc in France and a joint Technology Development Centre (TDC) located at Aldermaston in the United Kingdom. Research carried out at the two facilities enables France and the UK to ‘ensure the safety and reliability of their nuclear warheads in a safe, secure environment, without having to conduct any nuclear tests.’15
US–French cooperation is conducted under a 1961 Mutual Defence Agreement, which permits limited cooperation on the operation of nuclear-weapon systems and amounts to (mutual) assistance with possession and stockpiling. Later amendments have enabled enhanced cooperation, notably on issues of safety, security, and reliability.16
As discussed above under the prohibitions on transfer and on receiving transfer or control of nuclear weapons or other nuclear explosive devices, the United Kingdom and the United States continue to engage in close cooperation on the UK’s nuclear-weapons capability, including on the maintenance of Trident II submarine-launched ballistic missiles (SLBMs). The nature of the cooperation also amounts to US assistance with the United Kingdom’s possession and development of nuclear weapons.
- H. M. Kristensen, ‘NATO Steadfast Noon Exercise and Nuclear Modernization in Europe’, Federation of American Scientists, 17 October 2022, at: https://bit.ly/3kS0J9E.
- T. Nilsen, ‘Scandinavian fighter jets in joint training with American B-52 bombers above Arctic Circle’, The Barents Observer, 18 August 2022, at: https://bit.ly/3jbeqQI.
- V. Isachenkov, ‘Nuclear capable bombers fly over Belarus amid Ukraine tensions’, The Times of Israel, 6 February 2022, at: https://bit.ly/3WOD5Z2.
- D. Hurst, ‘US deployment of nuclear-capable B-52 bombers to Australia’s north likely to fuel China tensions’, The Guardian, 31 October 2022, at: https://bit.ly/3Hl2xj4.
- R. Tanter, ‘Hope Becomes Law’, Journal for Peace and Nuclear Disarmament, Vol. 4, No. 1 (2021), at: https://bit.ly/3HsI0JA.
- H. M. Kristensen and M. Korda, ‘Russian nuclear weapons, 2022’, Bulletin of the Atomic Scientists, Vol. 78, No. 2 (2022), at: https://bit.ly/3x1oa3j.
- P. Podvig, ‘Missile launches in 2022 and plans for 2023’, Russian Forces Blog, 16 December 2022, at: https://bit.ly/3HoLUmm.
- NATO, ‘NATO 2022 Strategic Concept’, 29 June 2022.
- Sweden’s letter of intent, 5 July 2022, at: https://bit.ly/3Rlw40E; Finland’s letter of intent, July 2022, at: https://bit.ly/3Hnkw8x.
- Australian Department of Defence, ‘2020 Defence Strategic Update’, Canberra, July 2020, at: http://bit.ly/2Pl065e, para. 2.22.
- International Law and Policy Institute, ‘Under my Umbrella’, 2016, p. 8.
- Muñoz, Risky Returns. The 24 companies are: Aerojet Rocketdyne Holdings, Inc (United States), Airbus Group (The Netherlands), BAE Systems plc (United Kingdom), Bechtel (United States), Bharat Dynamics Limited (India), Boeing (United States), China Aerospace Science and Technology (CASC), Constructions Industrielles de la Méditerranée (CNIM) (France), Fluor (United States), General Dynamics (United States), Honeywell International (United States), Huntington Ingalls Industries (United States), Jacobs Engineering (United States), L3 Harris Technologies (United States), Leidos (United States), Leonardo (Italy), Lockheed Martin (United States), Northrop Grumman (United States), Raytheon Technologies Corporation (United States), Rostec (Russian Federation), Safran (France), Textron (United States), Thales (France), and Walchandnagar Industries (India).
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Etica Funds–Responsible Investments Chairman Ugo Biggeri, ‘Investor Statement to the First Meeting of States Parties to the Treaty on the Prohibition of
Nuclear Weapons’, Vienna, 21 June 2022, at: https://bit.ly/3DiT7Dt. - Muñoz, Risky Returns.
- The France-UK Teutates Programme website, at: https://bit.ly/3ZQwLT3.
- See, e.g., C. Mohr, ‘U.S. Secretly Helped France Develop Nuclear Weapons, an Expert Writes’, The New York Times, 28 May 1989, at: http://nyti.ms/2IcTBlc.