The prohibition on development, production, manufacturing, and other acquisition
The nine nuclear-armed states continued to engage in conduct in 2024 that was not compatible with the Treaty on the Prohibition of Nuclear Weapons’ (TPNW) prohibition on developing, producing, manufacturing, or otherwise acquiring nuclear weapons. Two further states not party to the TPNW—Iran and Saudi Arabia— were again recorded as states of concern. Disconcertingly, discussion on the possibility of pursuing nuclear armament also mounted in several other states not party to the TPNW—and most notably in Germany, Japan, and not least South Korea—despite their existing unequivocal obligations not to develop or acquire nuclear weapons under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The non-proliferation norm established by the NPT and reinforced by the TPNW is under increasing pressure.
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 2024 continued to actively develop and produce 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.
In 2024, the International Campaign to Abolish Nuclear Weapons (ICAN) documented that the nine nuclear-armed states’ spending on their arsenals surged to a combined total of US$91.4 billion in 2023. This was US$10.7 billion more than in the preceding year. Citing the report in his address to the UN General Assembly in September 2024, Brazilian President Luiz Inácio Lula da Silva commented: ‘These resources could have been used to combat hunger and address climate change.
Nuclear deterrence is an increasingly fragile system and nuclear weapons are a source of constant insecurity. Nevertheless, nuclear deterrence as a security ideology remains a core driver of investment in expensive and expansive nuclear modernisation. Nuclear modernisation is also typically prompted by several other interlocking factors.
The year 2024 also saw the rise of a renewed intermediate-range nuclear arms race – a class of weapon that had previously been banned for the United States and Russia under the now-defunct 1987 Intermediate-Range Nuclear Forces (INF) Treaty. Both the United States and Russia are developing weapons that would have fallen within the scope of that treaty.
The Nuclear Weapons Ban Monitor collaborates with the Federation of American Scientists’ (FAS) Nuclear Information Project to estimate and analyse global nuclear forces. A summary provided by FAS, intended to be a snapshot of each of the nine nuclear-armed states primary nuclear developments in 2024, can be found in the 2024 edition of the Nuclear Weapons Ban Monitor.
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 or warheads, 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 covers key components. It is widely accepted that the missile, rocket, or other munition, including both the container and any means of propulsion and launch capability, 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 aircraft and submarines are not key components of nuclear weapons as such, and are therefore not in and of themselves captured by the prohibitions in Article 1. They may, however, of course be integral to a nuclear-weapon system, and any components of a delivery platform that are designed specifically for the launching of nuclear weapons, are indeed captured by the prohibitions in Article 1.
‣ 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.
‣ 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.
‣ 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.
• As is the case with the NPT, the TPNW does not define ‘nuclear weapons’ or ‘other nuclear explosive devices’. There is, though, a settled understanding among states of these terms.
• A nuclear explosive device is an explosive device whose effects are derived primarily from nuclear chain reactions.
• A nuclear weapon is a nuclear explosive device that has been weaponized, meaning that it is contained in and delivered by, for example, a missile, rocket, or bomb.
• Thus, all nuclear weapons are a form of nuclear explosive device but not all nuclear explosive devices are nuclear weapons.