How likely is the use of nuclear weapons by Russia?

Exploring key questions around Putin issuing what was interpreted as a threat to use nuclear weapons against NATO countries if they interfere in Ukraine.

Explainer Updated 25 November 2024 6 minute READ

Dr Patricia Lewis

Research Director; Director, International Security Programme

What is Putin’s nuclear weapons threat?

On 24 February 2022, in a televised speech heralding the Russian invasion of Ukraine, President Vladimir Putin issued what was interpreted as a threat to use nuclear weapons against NATO countries should they interfere. ‘Russia will respond immediately’ he said, ‘and the consequences will be such as you have never seen in your entire history’.

Then on 27 February 2022, Putin ordered Russia to move nuclear forces to a ‘special mode of combat duty’, which has a significant meaning in terms of the protocols to launch nuclear weapons from Russia. 

In September 2022…(Putin) indicated a stretch in Russian nuclear doctrine, lowering the threshold for nuclear weapons use.

According to Russian nuclear weapons experts, Russia’s command and control system cannot transmit launch orders in peacetime, so increasing the status to ‘combat’ allows a launch order to go through and be put into effect.

Putin made stronger nuclear threats in September 2022, following months of violent conflict and gains made by a Ukrainian counterattack. He indicated a stretch in Russian nuclear doctrine, lowering the threshold for nuclear weapons use from an existential threat to Russia to a threat to its territorial integrity. 

In November 2022, according to much later reports, the US and allies detected manoeuvres that suggested Russian nuclear forces were being mobilized. After a flurry of diplomatic activity, China’s President Xi Jinping stepped in to calm the situation and speak against the use of nuclear weapons.

In September 2024, Putin announced an update of the 2020 Russian nuclear doctrine. The update was published on 19 November 2024 and formally reduced the threshold for nuclear weapons use. 

The 2020 doctrine said that Russia could use nuclear weapons ‘in response to the use of nuclear and other types of weapons of mass destruction against it and/or its allies, as well as in the event of aggression against the Russian Federation with the use of conventional weapons when the very existence of the state is in jeopardy’.  

On 21 November 2024, Russia attacked Dnipro in Ukraine using a new ballistic missile for the first time.

The 2024 ‘New Basic Principles of State Policy of the Russian Federation on Nuclear Deterrence’ refers instead to aggression against Russia or Belarus ‘with the use of conventional weapons creating a critical threat to their sovereignty or territorial integrity’. Specific types of conventional weapons are also defined in the document as a ‘massive launch’ of aircraft, cruise missiles, UAVs and other flying devices. 

Russia’s new nuclear doctrine was months in the making. Although it was released soon after President Biden’s announcement allowing Ukraine to use medium-range conventional missiles (ATACMS) against Russian territory, it was not a direct consequence of that decision.

On 21 November 2024, Russia attacked Dnipro in Ukraine using a new ballistic missile for the first time.

President Putin announced the missile as the ‘Oreshnik’, which is understood to be a nuclear-capable, intermediate-range ballistic missile which has a theoretical range of below 5,500km. 

The missile reportedly launched from South-eastern Russia (Astrakhan Oblast) was conventionally armed. 

Both the US and Russia confirmed that the US was notified of the missile launch prior to the attack through the normal nuclear risk reduction protocols and channels.

Russia has fired conventionally armed nuclear-capable missiles at Ukraine throughout the war, but the Oreshnik is much faster and harder to defend against, and suggests an escalatory intent by Russia.

These developments are escalating what was already a highly dangerous situation in which mixed messaging with the potential for misinterpretation could lead to decisions being made under false assumptions – there is a well-documented history of close calls with nuclear weapons.

Nuclear weapons deterrence was developed in the Cold War primarily on the basis of what was called ‘mutually assured destruction’ (MAD). The idea behind MAD is that the horror and destruction from nuclear weapons is enough to deter aggressive action and war. 

But the application of deterrence theory to post-cold war realities is far more complicated in the era of cyberattacks and AI, which could interfere with the command and control of nuclear weapons. 

In light of these risks, presidents Biden and Xi issued a joint statement from the 2024 G20 summit affirming the need to maintain human control over the decision to use nuclear weapons.

Which countries have nuclear weapons?

There are five recognized nuclear weapons states under the global nuclear Non-Proliferation Treaty (NPT) – China, France, Russia, the UK, and the US. Almost every country in the world participates in the NPT but outside the Treaty three more countries openly declare their possession of nuclear weapons – India, Pakistan, and North Korea. Israel has not declared the possession of nuclear weapons but is assumed to have them.

There are no longer any agreements between the US and Russia regulating the number or the deployment of ground-launched nuclear missiles with a range of 500-5,500 kilometres.

Nuclear weapons can be divided into different categories depending on their delivery vehicles and launch platforms – land, sea, or air missiles and short, intermediate, and long-range missiles. 

The US and Russia exchange information on their strategic, long-range nuclear missiles under the New START agreement – a treaty to reduce and monitor nuclear weapons between the two countries which is set to expire in February 2026.

But with the US decision to exit the Intermediate Nuclear Forces (INF) Treaty in 2019, there are no longer any agreements between the US and Russia regulating the number or the deployment of ground-launched nuclear missiles with a range of 500-5,500 kilometres. Short-range nuclear weapons were withdrawn and put in storage as a result of the 1991 Presidential Nuclear Initiatives but are not subject to any legal restraints.

The 10th NPT Review Conference was held in 2022 in New York. The issue of nuclear weapons threats and the targeting of nuclear power stations in Ukraine were central to the debate. 

A document was carefully crafted to finely balance concerns about the three pillars of the treaty – non-proliferation, nuclear disarmament and the peaceful uses of nuclear energy. But Russia withdrew its agreement on the last day of the conference, scuppering progress.

Since February 2022, each nuclear weapon state has been increasing focus on the readiness of military command and control of their nuclear weapons.

Would Russia use nuclear weapons?

Since 2022, it had been assumed that Russia would not attack a NATO state with nuclear weapons – which could trigger Article 5 of the Washington Treaty and set off a full NATO response. 

Increasingly the rhetoric from Russia suggests nuclear threats are a more direct threat to NATO.

It was believed that if Russia were to use nuclear weapons it would likely be in Ukraine, using short range, lower yield ‘battlefield’ nuclear weapons. Russia is thought to have more than 1,000 in reserve. These would have to be taken from storage and either connected to missiles, placed in bombers, or as shell in artillery.

Increasingly the rhetoric from Russia suggests nuclear threats are a more direct threat to NATO – not only Ukraine – and could refer to longer range, higher yield nuclear weapons.

For example in his 21 September 2022 speech, Putin accused NATO states of nuclear blackmail, referring to alleged ‘statements made by some high-ranking representatives of the leading NATO countries on the possibility and admissibility of using weapons of mass destruction – nuclear weapons – against Russia’.

He added: ‘In the event of a threat to the territorial integrity of our country and to defend Russia and our people, we will certainly make use of all weapon systems available to us. This is not a bluff.’

There have been no expressed nuclear weapons threats from NATO states. NATO does rely on nuclear weapons as a form of deterrence and has recently committed to significantly strengthen its longer-term deterrence and defence posture in response to Russia’s invasion of Ukraine. The current UK Labour government has repeatedly reiterated its commitment to British nuclear weapons – including before the July 2024 election. 

Any movement to ready and deploy Russian nuclear weapons would be seen and monitored by US and others’ satellites, which can see through cloud cover and at night – as indeed appears to have happened in late 2022. 

Depending on other intelligence and analysis – and the failure of all diplomatic attempts to dissuade Russia – NATO countries may decide to intervene to prevent launch by bombing storage sites and missile deployment sites in advance.

But there are enormous risks associated with this decision. Such a strike might precipitate a far worse attack from Russia and could be characterized as an act of aggression by NATO rather than of pre-emptive defence. 

However, not to pre-empt would leave Ukraine or other countries – including the UK, US, and other NATO states – open to nuclear weapons explosions with the possibility of hundreds of thousands dead, depending on the target.

How would NATO respond to a Russian nuclear attack?

If Russia were to attack Ukraine with nuclear weapons, NATO countries would most likely respond on the grounds that the impact of nuclear weapons crosses borders and affects the countries surrounding Ukraine. NATO could either use conventional forces to attack Russian strategic assets or respond in kind using nuclear weapons.

The US has around 150 B-61 nuclear gravity bombs stationed in five NATO countries – Belgium, Germany, the Netherlands, Italy, and Turkey. The US, UK, and France also have long range capability for nuclear attacks under NATO auspices.

But both scenarios mean NATO being drawn into a major war with Russia. The advantage of deciding to hold back on nuclear retaliation – and communicating that response as NATO has repeatedly done throughout the conflict – is that Putin cannot credibly portray NATO as threatening Russia with nuclear weapons.

It is always possible that Putin may decide to launch a long-range ballistic missile attack against the US or the UK. But he knows – as do all his officials – that this would be the end of Russia.

If such a decision were made, it is hoped senior military personnel would recognize the full implications and choose to take other actions. History is replete with instances of close calls when individuals acted to prevent a dangerous situation from escalating to full nuclear weapons use.  

Does or did Ukraine have nuclear weapons?

As part of the USSR, Ukraine hosted Soviet nuclear missiles along with Belarus and Kazakhstan. At the end of the Cold War, Ukraine hosted approximately one-third of the Soviet Union’s nuclear weapons but did not have control over them and so could not have launched them.

In 1994, Ukraine committed to joining the NPT as a non-nuclear weapon state and agreed to transfer all nuclear warheads to Russia for elimination by 1996. As part of this arrangement, Russia, the UK, and the US along with Ukraine, Belarus, and Kazakhstan signed the Budapest Memorandum to provide security assurances if the former Soviet states joined the NPT as non-nuclear weapon states.

The Memorandum agreed that Belarusian, Kazakh, and Ukrainian independence and sovereignty would be respected in the extant borders. It also stated that parties would refrain from the threat or the use of force – and specifically from the use of nuclear weapons – against Belarus, Kazakhstan, and Ukraine, and from using economic pressure to influence their politics.

In October 2024, Ukrainian President Volodymyr Zelenskyy explained that Ukraine prefers to join NATO over developing its own nuclear weapons.

They also agreed immediate UN Security Council action to help Belarus, Kazakhstan and Ukraine if they were a ‘victim of an act of aggression or an object of a threat of aggression in which nuclear weapons are used’.

From December 2023, Belarus has allowed Russian forces and nuclear weapons to be hosted on a permanent basis, going against the terms of the Budapest memorandum. Belarus also allowed Russian troops to use Belarusian territory to invade Ukraine from the north.

In October 2024, Ukrainian President Volodymyr Zelenskyy explained that Ukraine prefers to join NATO over developing its own nuclear weapons, saying that ‘Ukraine’s survival can only be ensured by joining NATO or giving Kyiv nuclear weapons… NATO countries are not at war. People are all alive in NATO countries. And thank God. That is why we choose NATO. Not nuclear weapons.’