Russia’s Use of Chemical Weapons: A Slippery Slope

Russia’s Use of Chemical Weapons: A Slippery Slope

On July 4, 2025, the Dutch and German intelligence services jointly published information on the intensification of Russia’s use of chemical weapons in Ukraine. While the use of teargas by the Russian armed forces is not new, the confirmation of the use of chloropicrin is. Chloropicrin is a more aggressive and potentially deadly chemical, making this a worrying development. Accusations of the use of chloropicrin have been brought up before, but sound evidence was missing at the time. This brief explores various responses of international actors, including the Organisation for the Prohibition of Chemical Weapons (OPCW), to accusations of chemical weapons usage. Official (OPCW) documents, media coverage, and other sources have been used to produce this brief.

Systematic Implementation

According to the intelligence report, the utilization of chemical weapons is not only limited to battlefield experimentation, but is part of a systematic, large-scale Russian chemical weapons programme. When Russia ratified the Chemical Weapons Convention (CWC) in 1997, it was obliged to destroy its entire chemical weapons arsenal. In 2017, the OPCW announced that Russia’s declared chemical weapons stockpile was destroyed. However, the CWC only mandates the destruction of chemical weapons, not defensive military units responsible for the development of such weapons. On October 8, 2024, the UK sanctioned Russia’s Radiological Chemical and Biological Defence (CBR) troops. Although officially labeled as defensive, the UK and other governments have sanctioned this branch of Russian defence for allegedly being part of a larger systematic implementation of chemical weapons, such as chloropicrin, on the battlefield in Ukraine. Since the CBR troops are classified as defensive, Russia could legally maintain them without violating the CWC. Yet it appears that this has now backfired: these units are being used offensively, functioning as an apparatus for prohibited chemical use.

The use of chemical weapons by Russia has been widely documented throughout the Russo-Ukrainian War. As early as April 2022, the Azov battalion reported that three soldiers were injured by a “poisonous substance” during the siege of Mariupol. UK foreign secretary Liz Truss said at this early point in the war that this was “a callous escalation”. The recent intelligence report confirms that the use of both chloropicrin and teargas has become “standard practice and commonplace.” Dutch Defense Minister Ruben Brekelmans states that the employment of these weapons is a slippery slope, encapsulating the multidimensional risk of this intensification, where the shift from occasional to casual use of chemical weapons endangers the legal barrier of their usage. Once normalized, chemical weapons usage threatens all of Europe and could spread globally, eroding the universal taboo established by the CWC. This marks a potential for widespread adoption of chemical weapons as a recognized tactic.

International Organisations

The CWC is a multilateral agreement administered by the OPCW and was signed by Russia in 1993. The Convention understands chemical weapons to be “any toxic chemical, used for its toxic properties with the purpose to cause harm or death”. The Ukrainian ministry of defence has reported that Russia has used chemical weapons in more than 9000 attacks. This marks a significant violation to the Convention, especially considering the choking-effect chloropicrin has. The European Commission has responded to previous reports of chemical weapons usage in Russia by sanctioning various entities in the Russian Armed Forces, including asset freezes, the prohibition of provision of economic resources and a travel ban to the EU. The intelligence reports were also cited after the EU Foreign Affairs Council on July 15 by Kaja Kallas, also in light of Trump’s pledge to manufacture more weapons for Ukraine. The United States (US) already reported chloropicrin use by Russia in May 2024, but the OPCW concluded that the evidence was insufficient. Following the Dutch and German intelligence reports, Ukraine requested the OPCW to conduct an investigation on the use of chemical weapons in the war. Besides the formal request in advance of the OPCW Executive Council meeting, the delegation of Ukraine also made a statement during the meeting. They note in the addendum that Russia’s use of chemical weapons threatens the “integrity of the international community’s commitment to make a world free of chemical weapons”.

With the stalemate at the frontline, the use of chemical weapons might be a Russian tactic to force a breakthrough. Additionally, it also serves as a means to signal defiance, provoke fear, and also to try and make Ukraine break its commitments to international law. Consequently, a swift and clear response by the OPCW and the international community is necessary to minimise the risk of violations of the CWC in the future. Especially considering Russia’s investment in the development of more chemical weapons, the situation should be monitored closely. Signatories of the CWC should not get the impression that violations of the Convention go unnoticed and unsanctioned.

How Can the OPCW Respond?

The possibilities of response by the OPCW are listed in Article X of the Convention. This includes support in training and equipment for protection against chemical weapons, which has been and will be provided to Ukraine. The training has been ongoing since July 2024, during which Ukrainian experts receive training in investigative skills. Another possibility for the OPCW are technical assistance visits. The OPCW has deployed technical assistance visits to Ukraine, in which they “collected related documentation and digital files, as well as testimonies from first-hand witnesses, and received seven environmental samples collected by Ukraine”. These took place already before the publication of the Dutch and German intelligence reports. Through these technical assistance visits, it was confirmed that CS gas (tear gas) was used in the investigated area. However, the OPCW only determined that CS gas was used, not who used it. And of course, Russia has denied the allegations. On July 7, the Ukrainian Permanent Representation to the OPCW requested an “independent and impartial mechanism to investigate the alleged use of weapons, including the identification of perpetrators”. In response, Russia had requested the circulation of a document and documentary that accuses Ukraine of violating the CWC.

In conclusion, the Dutch and German intelligence reports have confirmed escalation in the frequency and nature of chemical weapons usage by Russia. Ukraine’s request to the OPCW to investigate further and to identify the perpetrator will be important for the OPCW’s next steps. The situation needs to be monitored closely to protect the credibility of the CWC and prevent further deterioration of compliance in other signatories as well.