The prohibition on development, production, manufacturing, and other acquisition

The nine nuclear-armed states continued to engage in conduct in 2023 that was not compatible with the TPNW’s prohibition on developing, producing, manufacturing, or otherwise acquiring nuclear weapons. Two further states not party—Iran and Saudi Arabia—were again recorded as states of concern.

NWBM 2023 NTB Wp4f Ke Zd NT0 — In this photo released on 7 October 2023, the Russian Defense Minister Sergei Shoigu, centre, inspects the serial production of the fifth-generation strategic missile system Sarmat. **Photo:** Photo by the Russian Defense Ministry Press Service via AP/NTB

Although most nuclear-armed states brand their ongoing development and production efforts as nuclear ‘modernisation’, their actions go well beyond simple maintenance and sustainment operations. In reality, every nuclear-armed state in 2023 continued to actively engage in the development and production of new nuclear warheads and/or delivery vehicles, in addition to upgrading their existing nuclear capabilities. Moreover, against the backdrop of rising global tensions, many nuclear-armed states are increasing the roles of nuclear weapons in their military doctrines, with some actively engaging in armed conflict and/or great power competition.

Nuclear modernisation is typically prompted by several interlocking factors. These include the long timelines of weapons development, the tremendous influence of corporate lobbyists on nuclear policy decisions, and the lack of arms control treaties keeping arsenals in check. Nuclear modernization is also an inherent feature of the 21st-century nuclear arms competition, as states continuously seek to negate their adversaries' advantages. Finally, a core driver of nuclear modernization is nuclear deterrence as a security ideology. Not only are nuclear risks increasing to levels not seen since the end of the Cold War, but nuclear-armed states are also becoming increasingly opaque about their nuclear forces. This is highly problematic, as ambiguity about nuclear stockpiles, deployments, and employment policies can lead to worst-case assumptions about how countries will develop or use nuclear weapons in the future. This exacerbates the arms race and increases the possibility of miscalculation, particularly during times of heightened nuclear tensions.

The Nuclear Weapons Ban Monitor collaborates with the Federation of American Scientists’ Nuclear Information Project to estimate and analyse global nuclear forces. For a summary of the nine nuclear-armed states' primary nuclear developments in 2023, please refer to the 2023 edition of the Nuclear Weapons Ban Monitor.

ARTICLE 1(1)(a) INTERPRETATION

Each State Party undertakes never under any circumstances to: 'Develop, [...] produce, manufacture, otherwise acquire [...] nuclear weapons or other nuclear explosive devices.'

The prohibited ‘development’ of a nuclear weapon or other nuclear explosive device encompasses any of the actions and activities intended to prepare for its production. This covers relevant research, computer modelling of weapons, and the testing of key components, as well as sub-critical testing (i.e. experiments simulating aspects of nuclear explosions using conventional explosives and without achieving uncontrolled nuclear chain reactions).
The concepts of ‘production’ and ‘manufacture’ overlap significantly, covering the processes that are intended to lead to a completed, useable weapon or device. In general parlance, ‘production’ is a broader term than ‘manufacture’: manufacture describes the use of machinery to transform inputs into outputs. Taken together, these concepts encompass not only any factory processes, but also any improvisation or adaptation of a nuclear explosive device.
The prohibition on ‘otherwise acquiring’ a nuclear weapon or other nuclear explosive device is a catch-all provision that encompasses any means of obtaining nuclear weapons or other nuclear explosive devices other than through production. This could be through import, lease, or borrowing from another source or, in theory, by recovering a lost nuclear weapon or capturing or stealing one. This prohibition overlaps with the one in Article 1(1)(c) on receiving the control over nuclear weapons or other nuclear explosive devices (discussed below).
The prohibition on development, production, manufacturing, and acquisition also cover key components. It is widely accepted that the missile, rocket, or other munition, including both the container and any means of propulsion, are key components in a nuclear weapon. Test-launches of missiles designed to carry nuclear weapons are often used to validate particular systems or subcomponents and therefore constitute prohibited development of nuclear weapons. Delivery platforms such as bombers and submarines are not key components of nuclear weapons as such, and are not captured by the prohibitions in Article 1, although they may of course be integral to a nuclear-weapon system.
Key components are also the fissile material (plutonium or highly enriched uranium) and the means of triggering the nuclear chain reaction. Production or procurement of fissile material constitutes prohibited development when this is done with the intent to produce nuclear weapons or other nuclear explosive devices. To research, produce, and use nuclear energy for peaceful purposes is permitted both under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) and the TPNW.
Development and production of dual-use components, such as navigation or guidance systems, which could be used in both nuclear and conventional weapons, would only be prohibited under the TPNW when they were intended to be used in nuclear weapons.
Under Article II of the NPT, a similar obligation is imposed not to manufacture or otherwise acquire nuclear weapons or other nuclear explosive devices, but this applies only to the non-nuclear-weapon states designated under the Treaty and does not prohibit the designated nuclear-weapon states from continuing to develop, produce, and manufacture nuclear weapons or other nuclear explosive devices.

The TPNW and mining and transfer of uranium

Under international law, mining and transfer of uranium is generally lawful, unless it is being done 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 customary international law), 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 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 party 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 subject to IAEA safeguards and 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, affect the legality of any 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 either of 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.