The Russians Are Using Riot Control Agents in Ukraine
What does it mean for U.S. policies and warfighting concepts?
In May of this year, the U.S. State Department announced that the Russian military had repeatedly used a chemical weapon, namely chloropicrin, against Ukrainian forces in defensive positions. As a result, the State Department sanctioned three Russian government agencies, the Russian Army’s Radiological, Chemical, and Biological Defense Troops and two scientific research institutes. You can probably guess without reading the full text of the State notice that U.S. diplomatic sanctions against Russia are not exactly news. The State Department also announced sanctions against Russia after the Skripal incident in 2018 and the Navalny poisoning in 2020. As a signatory of the Chemical Weapons Convention, Russia is not supposed to have an active chemical weapons program, but I don’t know, I think they might be doing something nefarious in this field.
(OpenAI art, not an actual photo of a Russian soldier in a protective mask)
The Russian use of chloropicrin in Ukraine is not a recent phenomena. Reports of chloropicrin use in Ukraine date back about two years ago, suggesting that Russian troops were using drones to deliver K-51 gas grenades into Ukrainian trenches. Characteristically, the Russian government claimed that it was the Ukrainian forces who were using chemical weapons in the regional conflict. To add to the confusion, the Russian government claimed that the United States had supported the development of biological weapons in Ukrainian laboratories under the DoD’s Cooperative Threat Reduction Program. This is absolute bunk, but the Russians don’t make these claims hoping for arbitration by the United Nations. This disinformation is mainly for domestic consumption.
The Organization for the Prohibition of Chemical Weapons (OPCW), the agency responsible for implementing the Chemical Weapons Convention, noted with regards to this issue that “any use, as a Riot Control Agent, of a toxic chemical belonging to one of the three Schedules listed in the Annex to the Convention on Chemicals would be contrary to the Convention.” Chloropicrin is in fact listed on the Schedule 3 of the treaty’s annex on chemicals. However, “the Secretariat has not received any such request for action” to investigate these allegations of toxic chemicals used as weapons. They’re still enjoying the win on getting consensus on adding Novichok agents to the CWC Schedule 1 list.
I’m sure that, given this evidence of Russian intent to use chemical weapons in modern conflicts, the U.S. military must be pushing hard to improve its protective gear and concepts for countering CBRN threats such as this. I’m just kidding, there are no planned increases of funding for the very small budget line dedicated to U.S. military CBRN defense. Not that anyone is auditing the DoD CBDP’s productivity because no military or civilian leader really thinks that chem-bio warfare is still a thing. But I digress. Let’s talk about chloropicrin and the concept of using riot control agents, a.k.a. tear gasses, on the battlefield. This figure shows trichloronitromethane, the formal name for chloropicrin, also known by its military brand “PS.”
Chloropicrin isn’t a gas, it is actually an oily liquid that was first employed as a pesticide to kill fungi and insects, in particular for strawberry crops. In fact, the Environmental Protection Agency approved the use of chloropicrin as a soil fumigant pesticide for U.S. farmers, with significant cautions about using the chemical with the correct protective measures. Coincidently, Russia is believed to be one of the first nations during World War I to use chloropicrin as a weapon, although the British, French, and Germans also adopted the chemical as a weapon (the United States produced chloropicrin munitions for WW1 but did not send any stocks overseas). Chloropicrin has a strong odor (like flypaper) and was much less toxic but more persistent than phosgene (another commercial chemical pressed into military use). These characteristics do not make for an ideal chemical weapon. On the other hand, chloropicrin could break through the carbon filters of the soldiers’ masks and irritate their lungs to the point that they would vomit, causing them to remove their masks. This made the soldiers vulnerable to other types of gas attacks that might be simultaneously happening. In large doses, it can be fatal.
To appreciate why chloropicrin was used at all, you have to understand the state of military R&D in 1915. All of the combatants in World War I were scrambling to develop chemical weapons that would allow them to break the trench warfare model that had emerged. Given that they had little to no prior experience in this field, not the least because the physical sciences were still growing out of their infancy as a commercial venture, the major actors used industrial chemicals in artillery shells and gas cylinders for use on the front. Practically all of these chemicals were abandoned as weapons after 1918 in favor for a few standards (e.g., mustard and phosgene). During WW2, the United States produced tear gas grenades with a fill of chorloacetophenone (CN). The Russians kept chloropicrin for training purposes and for riot control, perhaps because they don’t care as much about long-term health effects.
If chloropicrin is a riot control agent, why is it listed in a chemical weapons treaty? The Chemical Weapons Convention was largely drafted to address the tens of thousands of tons of chemical weapons held by the Soviet Union and United States during the Cold War. The idea of including RCAs in the treaty was a hotly debated issue, not the least because law enforcement and security forces like the idea of using a non-lethal or “less-than-lethal” chemical agent to disperse rioters. On the other hand, the U.S. military had used CS tear gas to flush out Viet Cong fighters from caves and tunnels, reducing the risk to U.S. soldiers who might have to root them out. When this information was revealed to the general public, there was an international uproar over the use of “poison gas” and allegations that the United States had violated international law. This attached paper has some good details as to the controversy.
In the general literature of the time, the concern voiced by arms control specialists was one of potential escalation - that if a nation was permitted to use non-lethal riot control agents during combat, it might feel emboldened to later use lethal chemical agents such as nerve agents. In addition, delivery systems designed to employ RCAs could easily be adapted to lethal chemical agents. This was an untested hypothesis, but that concern led to the very general language in the Chemical Weapons Convention, that “a chemical weapon is a chemical used to cause intentional death or harm through its toxic properties.” So that word “harm” is doing a lot of work there. The OPCW continues to say “a riot control agent is defined as any chemical not listed in a schedule which can produce sensory irritation or disabling physical effects rapidly in humans and which disappear within a short time following termination or exposure. The use of riot control agents as a method of warfare is prohibited by the CWC.” At the same time, U.S. military forces can be authorized to use RCAs during wartime in “defensive military modes to save lives.”
Why Should We Care?
To summarize, we’re talking about the use of a non-lethal 20th century riot control agent in the context of small hand grenades being used in an outdoor environment. Military soldiers are using them against other military soldiers for the purpose of gaining a tactical advantage in the field. The Russian use of RCAs during wartime is a violation of treaty, but what are we going to do? Write them a stern letter, telling them how angry we are? The U.S. government is already implementing economic and diplomatic sanctions on Russia, who is not really feeling the pain. The U.S. government is not going to strike Russian forces or bases with cruise missiles as it did to Syria after its chemical strikes on civilians, because Russia has nukes. Some of the U.S. military aid to Ukraine has included protective masks, but I don’t know if they’re standard kit for Ukrainian soldiers on the frontlines.
I do support the purpose of arms control - to disarm adversaries of particular weapons, create stability by limiting especially dangerous weapons, and maintaining an advantage over dangerous countries who might attain particular weapons. I am not sure that drawing a hard line over riot control agents being used on the battlefield is necessarily a smart play. No one is going to lose (or win) a war over the use of tear gas grenades, nor are these grenades part of the “cruel and unusual” part of warfare.
Here’s the odd thing. There are some in the United States who believe U.S. soldiers should use riot control agents during combat situations, in particular for battles within urban areas where there could be civilians and where insurgents hole up inside of buildings that could be rigged to blow. The U.S. military already has CS-filled hand grenades, smoke pots that burn hexachloroethane (HC), and white phosphorous artillery shells that could all be referred to as chemical munitions (but not toxic chemical munitions). You may or may not be surprised that these discussions started when U.S. forces were heavily engaged in Iraq. In 2006, Senator John Ensign (R-NV) had this remark in a SASC subcommittee hearing:
It is my belief that American military commanders at all levels should be authorized to employ riot control agents consistent with the legislation passed last year by Congress in order to save the lives of American service men and women, coalition partners, and innocent civilians.
I think we'd all agree that tear gas can be an essential alternative to the use of lethal weapons in combat. Contrary to the law, it is unacceptable that our military is, under current policy, banned from using tear gas for any purpose on any battlefield. Police officers in any city in America can use tear gas to gain control of chaotic situations and avoid loss of life.
It would seem to be merely common sense that our men and women carrying out the global war against Islamic fascism be afforded that same authority.
I know when I speak to Nevadans about this issue, they are astonished to learn that our military cannot use tear gas in the hunt for al Qaeda.
This is not right, and it must change.
Unfortunately, most of the frank discussion in that hearing was relegated to closed session so we don’t know the rest of the story, other than Executive Order 11850, signed in 1975, is still in effect. In 2018, noted urban warfare analyst and former Army officer John Spencer called for re-examining the policies that outlaw the use of flamethrowers and tear gas, particularly in the execution of urban combat.
Both flamethrowers and tear gas have been shown to be effective tools for clearing enemy forces from buildings without totally destroying them. Flamethrowers can penetrate small openings and fill fortified positions with both fire and smoke. Tear gas can force enemy forces to evacuate fortified positions within buildings, especially when the military objective is focused as much on reclaiming terrain as killing individual fighters. Today, soldiers have neither flamethrowers nor tear gas.
…
The changes needed to decrease the destructive nature of military operations to reclaim an occupied city will not be small. New approaches will require investments in new approaches, technologies, equipment, organizations, and training designed specifically for major urban assaults, as well as policy changes to allow the use of different weapons like flamethrowers or tear gas. Without these changes, we can expect to have to destroy cities to save them.
He doubled down on this proposition in 2021, noting that the Marines used CS-grenades in the Battle of Hue in 1968, and how this “provides a strong example of how tear gas, specifically, can be used in urban warfare to limit collateral damage and save the lives of soldiers.” In 2024, he remarked on the Armed Forces of the Philippines use of tear gas during counter-insurgent operations in 2017, allowing them to “defeat opposing forces without having to fight through rubble, while at the same time minimizing civilian casualties and making reconstruction after the battle faster and cheaper.” Others have built on this argument, questioning if the Battle of Fallujah in 2004 might have been better waged had U.S. forces been allowed to use RCAs.
The Chemical Weapons Convention is a solid piece of work and has helped create a world today where nearly all industrialized nations have eschewed the concept of chemical warfare. At the same time, the treaty doesn’t stop U.S. presidents from authorizing the use of RCAs in certain combat situations. Changing U.S. policy to allow the use of RCAs during combat could significantly shake the international community’s confidence in the treaty and cause others to believe that the U.S. government was not in compliance. But in examination of the Russian-Ukrainian conflict, we also need to recall that the characteristics of warfare change over time, and we need to re-examine U.S. policies and military capabilities for change as well.
If you are interested in more details about Russian use of chloropicrin in Ukraine, please read these posts by Jean Paul Zanders in The Trench.
Glad to see Al wading into this territory, which could use more analysis.
It was my understanding that the Russians were using both riot control agents (like CS or CN) *and* chloropicirin--which is not classed as a riot control agent, because of its physical properties and because it is listed in, i.e. restricted by, the Schedules of the Chemical Weapons Convention--and mostly the former and only a little of the latter. The former has apparently been delivered via gas grenades, often dropped from drones; I haven't seen any specific information about how the latter has supposedly been delivered.
There's also some evidence that Ukrainian forces are also using riot control agents, via gas grenades dropped from drones, possibly munitions captured from Russian forces.
Al says, "The Russians kept chloropicrin for training purposes and for riot control, perhaps because they don’t care as much about long-term health effects." That's intriguing; I'm curious what the source might be.
The whole question of whether and under what conditions military forces should be allowed to use riot control agents is a thorny one. One facet of that is that if riot control agents are allowed to be used for domestic law enforcement, can they be used during military occupations of foreign territory? The parties to the Chemical Weapons Convention appear to have decided not to clarify that for now. And as Al notes, the US has long reserved the right to use riot control operations in military operations more generally, under specific circumstances and subject to high-level authorization, and in tension with the Chemical Weapons Convention as it currently stands.
Statecraft is often about give and take via treaty verbiage. The effectiveness of US use of tear gas in combat in Vietnam can be debated; what is not debateable is that the US hasn’t used it since, and a couple war colleges teach the Mayaguez incident as an example of how CS should not be used in combat operations.
More importantly is the adage “it’s not not that you win, but how you win.” In a world of cameras in every hand, the widespread use of an RCA in combat operations is potentially detrimental to the life of the CWC. There is no way to tell which type of gas is being used and it risks normalizing gas use in warfare.
There is an argument to be made that the US should alter its stance on the CWC to exclude the use of any gas, including RCAs , in combat operations, to include low intensity conflicts. This move would bring the US in line with just about every other CWC signatory, and reduce the ambiguity surrounding RCAs.
RCAs are being used today in warfare in Ukraine, Palestine, Myanmar,and Iraq. This increase is spurred not only by a lack of global repulsion, but also the emergence of drone deployment of RCAs reducing the exposure to friendly forces. Increased prevalence of gas in combat increases global risk to US forces for many reasons, not the least of which is, as you pointed out, the US CBDP budget.