The prohibition on use
Of the nine states that possess nuclear weapons, none used them in 2024. The prohibition on use in the Treaty on the Prohibition of Nuclear Weapons (TPNW) therefore remained intact. However, 22% of all states had defence postures in 2024 that were based on preparedness for the use of nuclear weapons. Throughout the year, the risk of the use of nuclear weapons persisted as a real and immediate feature of world politics, and the danger of the escalation of conflicts involving nuclear-armed states was a significant, and growing, concern.
The year 2024 saw the nuclear-armed states and umbrella states continue a trend of reinforcing the value of nuclear weapons. The ‘taboo’ against the use of nuclear weapons was therefore under pressure, with previously exceptional discussion of the possible use of nuclear weapons becoming normal. Flight tests with nuclear-capable missiles nuclear-strike exercises, and other demonstrations of nuclear capability and readiness to use increased in number and were often widely publicised.
The majority of the world has consistently rejected nuclear weapons as unacceptable and unnecessary weapons. A total of 154 states—four-fifths of the world’s total of 197—maintained defence postures in 2024 that at the time were based exclusively on non-nuclear means. In stark contrast to their choices, 43 states, or 22%, had nuclear-weapons based defence postures that involve preparedness and a willingness to potentially use nuclear weapons. This was the nine nuclear-armed states and a total of 34 so-called nuclear umbrella states – meaning states with arrangements of extended nuclear deterrence with one or more nuclear-armed states. This is an increase of three on the situation when the TPNW was negotiated and adopted in 2017, due to Finland, North Macedonia, and Sweden changing defence posture to embrace nuclear deterrence and becoming umbrella states. In addition to this, many long-time umbrella states now lean more heavily towards the security logic of nuclear deterrence rather than nuclear disarmament in response to Russia’s invasion of Ukraine in 2022.
Concern about the risk of nuclear use increased in 2024. For example, UN Secretary-General António Guterres warned in July 2024 that ‘Humanity is on a knife’s edge. The risk of a nuclear weapon being used has reached heights not seen since the Cold War. States are engaged in the qualitative arms race. Technologies like artificial intelligence are multiplying the danger. Nuclear blackmail has reemerged, with some recklessly threatening nuclear catastrophe.
The view that nuclear deterrence provides security rests on an assumption that nuclear weapons-related risks can be known and that they can be controlled. However, evidence shows us that these risks are not knowable and not controllable, but subject to chance and luck. Once we accept that luck plays a role in the outcome of nuclear crises, nuclear deterrence as a legitimate and necessary paradigm becomes deeply questionable. What remains is that nuclear weapons are a source of constant insecurity in themselves, to all of us. Nuclear weapons policies that are not based on a holistic and human-centred understanding of risks and consequences therefore increase the risks of miscalculations and endanger national and global security.
Knowledge about the risks and humanitarian impacts of nuclear weapons is therefore essential information that decision makers, policy makers and the media have a responsibility to actively seek and understand, but which all too often is ignored or even actively suppressed.
For more information, see the 2024 edition of the Nuclear Weapons Ban Monitor.
Each State Party undertakes never under any circumstances to: ‘Use … nuclear weapons or other nuclear explosive devices.’
- Preventing use is a fundamental aim of the TPNW – unquestionably central to the Treaty’s object and purpose.
- To use a nuclear weapon or other nuclear explosive device is to launch, release, deliver, or detonate it with hostile intent or for so-called ‘peaceful’ use, such as in civil engineering. Intent can be discerned from the circumstances and does not have to be publicly espoused.
- Possession or deployment of nuclear weapons for the purpose of ‘deterrence’ does not amount to their use under the TPNW but is covered by the prohibition on possession in Article 1(1)(a).
- The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) does not address the use of nuclear weapons in so far as it allows ‘peaceful’ detonation of nuclear explosive devices by nuclear-weapon states. The Comprehensive Nuclear-Test-Ban Treaty (CTBT), which prohibits all such ‘peaceful’ nuclear explosions, has not entered into force.
- Nuclear weapons have not been used since August 1945 when the United States dropped a nuclear weapon first on Hiroshima and then, three days later, on Nagasaki. Other nuclear explosive devices have not been used since some 150 such devices were detonated for ‘peaceful’ use (for civil engineering purposes) between the second half of the 1950s and the end of the 1980s by the erstwhile Soviet Union and the United States.