In early March 2022, Russia alleged that Ukraine was developing biological weapons in laboratories run in cooperation with the United States. On 11 March, Russia convened a special meeting of the UN Security Council to discuss its concerns.

The US has refuted the allegations, accusing Russia, in turn, of creating a pretext for its own actions in Ukraine, including the possible use of non-conventional weapons, specifically chemical weapons.

This Insight examines the nature of chemical weapons, allegations of previous use by Russia and concerns among Western military chiefs that Russia could deploy them in Ukraine.

What are chemical weapons?

Under the Chemical Weapons Convention, the definition of a chemical weapon includes all toxic chemicals, and the reactants used in their production (precursors), that can be used to cause intentional death or harm through their toxic qualities.

How they are delivered depends on the nature of the chemical and how quickly it disperses. In a battlefield context, munitions, such as artillery shells or bombs can be used to weaponise chemical agents. Types of agents include Sarin, VX, mustard and chlorine gas.

Does Russia have chemical weapons?

During the Cold War, the Soviet Union had the world’s largest stockpile of chemical weapons: with the Organisation for the Prohibition of Chemical Weapons confirming it held almost 40,000 metric tons of chemical agents, including VX nerve gas, sarin, soman, mustard gas and phosgene.

In January 1993, Russia (the former Soviet Union) signed the Chemical Weapons Convention (CWC). Under the terms of that treaty, which came into force in 1997, the development, production, acquisition, stockpiling, retention, transfer or use of chemical weapons by States Parties is prohibited.

States Parties are required to declare all past chemical weapons activities; submit regular declarations about the production, processing and use of certain dual-use chemicals and allow routine inspections by the Organisation for the Prohibition of Chemical Weapons (OPCW), which monitors compliance with the Convention. The treaty also required existing stockpiles to be destroyed, as well as any chemical weapons abandoned on the territories of other States Parties, by no later than 29 April 2012.

Russia missed the 2012 deadline for the destruction of its stockpile. A subsequent agreement with the OPCW extended that deadline to 2020. In September 2017, however, the OPCW announced Russia had verifiably destroyed its chemical weapons stockpile.

Russia has since been accused of non-compliance with the CWC and for not making a complete declaration of its chemical weapons stockpile to the OPCW.

Salisbury incident

In March 2018, the UK Government accused Russia of a chemical weapons attack on UK soil after former Russian spy Sergei Skripal, and his daughter Yulia Skripal, were taken seriously ill in the city of Salisbury.

On 12 March 2018, then Prime Minister Theresa May gave a statement confirming the substance used was the same type of military-grade nerve agent as that already developed by Russia, part of a group of agents known as ‘Novichok’ agents. Three operatives of the Russian Military Intelligence Service, the GRU, have since been charged in relation to the incident which the Government has concluded “was almost certainly approved outside the GRU at a senior level of the Russian state”.

The involvement of the Russian state was an assessment shared by the UK’s allies and partners. Russia denied the accusations, however, calling them “unacceptable”.

Poisoning of Alexei Navalny

In August 2020 Russia was implicated, for a second time, in the poisoning of Russian opposition figure, Alexei Navalny, with a Novichok nerve agent. The UK, US and other allies “agreed that there is no plausible explanation for Mr Navalny’s poisoning, other than Russian involvement and responsibility” and called on the Kremlin to declare its Novichok programme to the OPCW. The Russian Government again denied any involvement.

The US State Department said in April 2021 that both of these attacks “make clear that Russia retains an undeclared chemical weapons program”(PDF).

In a statement to the Session of the OPCW Executive Council on 8 March 2022, the Russian ambassador to the OPCW said the United States was “the only State possessor today” and alleged that Western laboratories were developing Novichok chemical agents as part of efforts to reshape the Chemical Weapons Convention “in order to carry out their own geopolitical intentions”.


Russia has not directly used chemical weapons in Syria but continues to support the government forces of Syrian President Bashar al-Assad, who have been identified by the UN and OPCW as using chemical weapons against civilians on several occasions.

Creating a pre-text for use of chemical weapons?

Western military chiefs have expressed concern that Russia could resort to the use of chemical weapons in Ukraine. Analysts have questioned whether Russian military operations are achieving their objectives as quickly as might be expected, and that the Kremlin has underestimated the resistance of the Ukrainian people. In such circumstances there are fears that Russia could resort to non-conventional weaponry to achieve its objectives.

Russian forces have already been accused of using cluster munitions, thermobaric rockets, also known as vacuum bombs, and white phosphorous shells against civilian targets in Ukraine.

Russia has also been accused of seeking to create a false pretext for their possible use, by first accusing Ukraine of developing chemical and biological weapons, with assistance from the US. At a press conference on 15 March 2022 NATO Secretary General, Jens Stoltenberg called the claims “absurd” and expressed concern that “Moscow could stage a false flag operation, possibly including chemical weapons” to justify Russian use. He said any use of chemical weapons is “absolutely unacceptable” and “a violation of international law”. President Biden said Russia would “pay a severe price” for the use of chemical weapons, while the Polish President, Andrzej Duda, called any such use a “game changer” for the West.

Contravention of international law

Any use of chemical weapons would be in contravention of international humanitarian law, the Geneva Conventions, the CWC and would be considered a war crime under the Rome Statute of the International Criminal Court (ICC). Even though Russia is not a State Party to the ICC, the Prosecutor of the ICC confirmed the ICC has jurisdiction over acts committed during the conflict. An ICC investigation into Ukraine has been opened following referrals of the situation in Ukraine by State Parties to the Rome Statute.

 Further reading

About the author: Claire Mills is a researcher at the House of Commons Library, specialising in Russia, the former Soviet Union and defence.

Image: A soldier in a chemical protection suit by Siergiejevicz, Adobe Stock #280646178