The prohibition on threatening to use
In 2021, there was, in the view of the Nuclear Weapons Ban Monitor, no clear instance of threatening to use nuclear weapons, as prohibited under Article 1(1)(d) of the TPNW. The closest to an instance of threatening to use was a US simulation of nuclear strikes against Russia.
Each State Party undertakes never under any circumstances to: […] ‘threaten to use nuclear weapons or other nuclear explosive devices.’
• Article (1)(1)(d) prohibits threatening to use a nuclear weapon or other nuclear explosive device, regardless of whether such use would itself be a violation of international law or whether the device would be used in legitimate self-defence against foreign aggression. It is therefore broader in scope than the prohibition on threat of force in Article 2(4) of the UN Charter.
• To violate the TPNW, a threat of use must be credible in the circumstances. This means that the threat must emanate from a person or an authority in a position to either effect or direct the use of a nuclear explosive device. Typically, therefore, such a threat would be made by a senior, pertinent government official or the ruling party in a nuclear-armed state.
• The narrow wording in Article 1(1)(d) of the TPNW with the active verb ‘threaten to use’ also requires that any signalled intention by a state to use nuclear weapons be specific as to the target of possible use.
• Prohibited threats may, however, be implicit as well as explicit. A stated threat does not, therefore, have to refer to use of nuclear weapons, although it would be more likely to violate the norm in the TPNW should it do so.
• In certain circumstances of tension, a show of force by means of missile testing, an explosive test of a nuclear weapon, a military exercise involving possible use of nuclear weapons, or a nuclear strike exercise, could amount to unlawfully threatening to use nuclear weapons under the TPNW (along with other violations of the Treaty).
• Policies of nuclear ‘deterrence’ rest on willingness to use nuclear weapons. Accordingly, reflecting the severity of the danger, some experts take the view that a practice of nuclear ‘deterrence’ in and of itself constitutes an unlawful threat of use of nuclear weapons. It is the view of the Nuclear Weapons Ban Monitor that the broader concept of nuclear deterrence, where the threat to use nuclear weapons is general and not specific in nature, is not sufficient in itself to constitute threatening to use under the TPNW. Deterrence practices are, however, illegal under the prohibition on possession and stockpiling.
• The NPT does not prohibit the threat of use of nuclear weapons. Threatening to use a nuclear weapon or other nuclear explosive device is prohibited under Article 1(1)(d) of the TPNW. This is the case whether such use would itself be a violation of international law or whether the device would be used in legitimate self-defence against foreign aggression. It is therefore broader in scope than the prohibition on threat of force within Article 2(4) of the UN Charter.
The United States’ annual nuclear command and control exercise, ‘Global Thunder’, took place in November 2021. Russia claimed that, during this nuclear strike rehearsal, ten US strategic bombers approached towards Russia from both the west and the east, and that they had come within 20 kilometres of the Russian border. US authorities did not deny the substance of Russia’s claim, but said the manoeuvres had been announced publicly at the time and were carried out in ‘compliance with all national and international requirements and protocols’. Given the backdrop of tensions over Ukraine at the time, this particular drill was a provocative act and might constitute threatening to use nuclear weapons.
An even more provocative act was the Russian Grom-2022 Strategic Deterrence Force exercise in February 2022, which took place prior to the Russian invasion of Ukraine. This exercise will be discussed in greater detail in the 2022 edition of the Nuclear Weapons Ban Monitor, as will the implicit threats to use nuclear weapons made by President Vladimir Putin. During the early days of the Ukraine conflict, a number of such threats were made by Russia. In late February 2022, President Vladimir Putin warned the West of ‘consequences never seen before’. Following an order from the Russian President, the state of alertness of Russia’s nuclear forces was then heightened. In response, Jean-Yves Le Drian, the French Minister for Europe and Foreign Affairs, said: ‘Vladimir Putin must also understand that the Atlantic Alliance is a nuclear alliance.’ This statement also amounted to threatening to use nuclear weapons.
In previous years, Russian simulations of nuclear use against specific adversaries received significant attention in international media. These include simulations of nuclear strikes against Poland in 2009 and against Sweden in 2013.
Earlier in November 2021, Russia had also sent two nuclear-capable strategic bombers on a training mission over Belarus for two days in a row in a strong show of support for its ally amid a dispute over migration at the Polish border. The Russian military told the Associated Press news network that the bomber patrol ‘was not aimed against any third countries’. While it is possible under international law for military exercises to constitute a threat of use of force, the circumstances of these flights do not meet the threshold for threatening to use nuclear weapons under the TPNW.
Also in relation to Belarus, in the same month, President Alexander Lukashenko stated in a TV interview that ‘you understand that the war in Belarus will involve NATO and Russia. The war will be nuclear….’ While deliberately provocative, this was not tantamount to threatening to use nuclear weapons as Belarussian officials do not possess nuclear weapons or have control over use of any of Russia’s nuclear arsenal.
Test launches of missiles are often used to validate particular delivery systems or subcomponents; however, in some cases such test launches may also be used for sabre-rattling or nuclear signalling. The Nuclear Weapons Ban Monitor did not find that any of the known missile tests in 2021 amounted to threatening to use nuclear weapons under the TPNW. The closest was a test by India in October 2021, which was the first user trial of its Agni-V nuclear-capable ICBM with a range of 5,000 kilometres from an island off its east coast amid rising border tensions with China. .The Arms Control Association stated that the test was an ‘apparent effort to signal advances in its nuclear deterrent to China’. In 1998, UN Security Council Resolution 1172 had called upon India (and Pakistan) to ‘cease development of ballistic missiles capable of delivering nuclear weapons’.