An arrest has reportedly been made after the killing of Igor Kirillov, a Russian general, in Moscow on December 17. Kirillov was the commander of Russia’s Radiation, Chemical and Biological Protection Forces, and is thought to be the most senior military figure assassinated in Russia since the country invaded Ukraine nearly three years ago.
Ukrainia’s SBU security services have claimed responsibility for the attack, saying that Kirillov was “responsible for the mass use of banned chemical weapons”. As a war criminal he was a legitimate target and had been named in a trial in absentia, the SBU said.
Russia’s security service released a statement saying it had detained a 29-year-old man from Uzbekistan. It added that while under “interrogation he explained that he was recruited by the Ukrainian special services”.
The issue of Russia’s alleged use of chemical weapons in Ukraine was put firmly on the international agenda in May 2024, when the US imposed new sanctions on Russia, accusing it of resorting to the use of tear gas and chloropicrin, an odourless toxic irritant, on the battlefield in Ukraine.
However, there have been unconfirmed reports of chemical weapons being used by Russian forces along the frontlines since as early as April 2022. If accurate, this would suggest the use of chemicals did not arise simply out of a need by the invading forces to fill gaps in the supply of conventional munitions to the battlefield.
Chemical weapons have been outlawed for nearly a century, since the Geneva protocol of 1925. The existing chemical weapons convention (1993/1997) is one of the most successful pieces of international law, certainly in terms of geographical reach. Only four UN-recognised states have not ratified the treaty, making it nearly universal.
Unlike other weapons treaties, the convention not only outlaws the use of chemical weapons, but also their production and development. This makes the prohibition absolute: these substances are not to be used to cause harm to humans in warfare. This prohibition applies to extremely lethal nerve agents and non-lethal tear gas alike.
The Assad regime’s use of chemical weapons against its own population during the Syrian civil war also shows the strength of world reaction in favour of prohibition against their use. In August 2013, credible reports emerged that Syrian government forces had bombarded civilians in the opposition-controlled Damascus suburbs of east and west Ghouta, using sarin or a similar weapons-grade nerve agent.
The attacks received huge condemnation in the international media and led to the only direct military interventions by western countries against the Assad regime.
Use in Ukraine
In November 2024, the Organization for the Prohibition of Chemical Weapons confirmed the presence of CS gas (tear gas) in samples collected in trenches in the Dnipropetrovsk region of eastern Ukraine. The substances appear to have been delivered either by grenades or by drones.
The effect of such attacks largely depends on whether the targets are expecting them. Tear gas and more toxic chemicals, such as chloropicrin, are far more effective against unsuspecting and unprepared targets than against a well-equipped professional army.
In the first case, it causes painful irritation to the eyes, lungs and skin, and can even cause incapacitation by inducing bouts of vomiting. This effectively leaves targeted sections in frontlines undefended. Fleeing soldiers are vulnerable.
For well-trained and protected troops, chloropicrin is more likely to cause mild irritation. However, the effects of this should not be underestimated: protective equipment limits movement, and the threat of gas continues to be psychologically taxing. It also causes an additional strain on medical services and puts more pressure on rotating troops.
The use of various chemical substances has been reported at various locations in eastern and southern Ukraine, including Bakhmut, Mariupol and Donetsk.
While the alleged use of chemical weapons by Russia may have resulted in short-term tactical advantages, it’s unlikely they would have caused cause significant shifts in the position of the frontlines.
Sending a message
But the use of chemical weapons is also a message that signals a willingness to transgress – not just international law, but also international norms. It’s a very nuanced process.
At no point have Russian officials denied that use of chemical weapons is both illegal and immoral. In fact, when accused of using them, it has issued strong denials and turned the accusations against Ukraine.
EPA-EFE/Yuri Kochetkov
But in their use, a message of defiance emerges. In Russia’s case, it would be a confirmation of Putin’s willingness to defy the idea of an international rule-based order. This has effects beyond the battlefield, provoking fear in Ukrainian defenders but also challenging Ukraine’s own commitment to play by the rules.
When debating whether Russia would stoop to the use of chemical agents, it’s important to remember that this is not the first time that Russia has allegedly done so in the 21st century.
In March 2018, the former Russian intelligence officer Sergei Skripal and his daughter Yulia were the targets of an attack using the nerve agent novichok in Salisbury in south-west England. And in 2021, opposition leader Alexei Navalny was similarly poisoned with novichok while travelling from Tomsk to Moscow.
For its part, Ukraine’s political leadership has always made a point of its defence of international norms and the rules-based order. But this assassination – and Kyiv’s willingness to accept responsibility for it – suggests it can create its own messages of defiance.
