Reports emerged from Ukraine on April 11, 2022, alleging that Russia had used a drone to drop an unknown chemical agent in the besieged southern city of Mariupol.
There has been no official confirmation of these reports as of April 12. But the Pentagon has said the news reflects U.S. concern about Russia’s “potential to use a variety of riot control agents, including tear gas mixed with chemical agents, in Ukraine.”
A chemical weapon can be any chemical that is used to harm people, including to injure or kill them. Many substances have been used as chemical weapons. Nerve agents are the deadliest, because they require a smaller dose to be fatal.
As an expert who has studied the use of chemical weapons in Syria’s civil war, I have thought since Russia first attacked Ukraine that the likelihood of Russia using chemical weapons there is low. Russia has little political or military motivation to use them and would face strong international rebuke and possible military consequences for this kind of attack.
But as recent reports might indicate, Russian use remains a possibility under certain circumstances. This is particularly true if Russian President Vladimir Putin believes chemical weapons are the only way to break a stalemate in a key battle zone.
Chemical weapons in Syria
The ongoing Syrian civil war offers the most recent example of widespread chemical weapons attacks on civilians.
There have been reports of more than 300 chemical attacks in Syria since the war began in 2012. A joint team from the United Nations and the Organization for the Prohibition of Chemical Weapons investigated some of the larger attacks, and conclusively attributed several to the Assad regime.
Russia, an ally of Syrian President Bashar al-Assad, continued supporting the Syrian government despite these attacks.
The Assad regime used chemical weapons on its own people because it feared what would happen if it lost the war. Assad would lose power if rebel parties defeated him. Assad and his associates also worried they could be killed.
In August 2012, President Obama warned Syria against chemical weapon use, stating it would be “a red line” for the U.S.
By the end of 2012, reports began to emerge of the Syrian military’s carrying out chemical attacks.
In August 2013, Syrian forces carried out the largest chemical attack of the war. They fired rockets containing the nerve agent sarin into Ghouta, a Damascus suburb, killing an estimated 1,400 people, including children.
Russia increased its support for Assad after these strikes.
Russia did, however, work with the U.S. to persuade a reluctant Assad in 2013 to sign the Chemical Weapons Convention, an international treaty that outlaws both possession and use of such weapons. Putin feared that without this deal, a possible U.S. military response could grow into an effort to prompt regime change in Damascus and make Russia lose its closest ally in the Middle East.
The deal led to destruction of more than 1,300 tons of Syrian chemical agents by early 2016. It also persuaded the Obama administration to refrain from military action in Syria.
Nevertheless, in 2014, Syria resumed attacks using chlorine, which can be deadly. Syria later also returned to occasional use of sarin.
Russian forces never used chemical weapons themselves, but they did conduct massive airstrikes – similar to the ones used on multiple cities in Ukraine – that destroyed significant portions of the Syrian city of Aleppo in 2016.
In the Syrian war, chemical weapons were part of a counterinsurgency campaign by Assad to hurt rebel forces and their civilian supporters.
Syria had two clear objectives for using chemical weapons.
First, most attacks served a psychological purpose. They were intended to terrify civilian populations so they would stop hiding rebel forces in their communities. Second, some of the larger attacks aimed to drive rebel forces out of areas they controlled.
These chemical attacks were not necessarily effective at reaching this military goal.
Instead, they were largely a function of desperation. Assad escalated chemical attacks when his army began to run short on manpower and conventional munitions – especially in areas where his regime was losing control.
Russia and chemical weapons
Russia has twice been accused of using chemical weapons in attempted political assassinations.
In 2018, Russia poisoned a former Russian double agent living in the U.K., Sergei Skripal, and his daughter with Novichok, a nerve agent developed by the Soviet Union in the final years of the Cold War.
The Skripals survived, but two other people who accidentally came in contact with the Novichok died as a result.
In 2020, Russia also attempted to poison opposition leader Alexei Navalny with Novichok. Navalny was hospitalized and almost died, but he ultimately recovered.
Russia has never admitted possessing Novichok. But the two assassination attempts show that Russia likely retains elements of a chemical weapons program.
There are other examples of Russia’s using chemicals in law enforcement operations that turned deadly. In October 2002, after Chechen militants held more than 900 people in a Moscow theater hostage, Russian security services pumped a gas into the theater.
The potency of the gas killed more than 100 of the hostages. Russia never revealed the gas it used, but experts believe it was a form of the opioid fentanyl.
Implications for Ukraine
It is clear that Putin would have no moral issue with using chemical weapons. But at the moment, Russia likely feels no pressing need to use them.
The conditions that motivated the Assad regime – a shortage of conventional forces and fear of being overthrown – do not apply to Russia’s situation in Ukraine.
Although Russian forces face rising casualty numbers in Ukraine, Russia still has the military capacity to continue fighting at a conventional level. And because the war is not taking place inside Russia, Putin is not at risk of being toppled by Ukrainian forces if they win the conflict.
Russia’s ability to terrorize civilians – a major goal of chemical weapons use – might also be limited.
A chemical attack may not have the intended psychological effect of demoralizing civilians. Putin appears to have misjudged Ukrainian civilians’ fortitude. Ukrainians would likely want to keep fighting even if Russia used chemical weapons against them.
This situation could change if the Russian military is on the brink of a decisive defeat. Then, desperation might lead Putin to consider a chemical option.
Although the risk of chemical weapon use, and especially large-scale use, remains low, it does remain possible.
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