“For half a century, ACA has been providing the world … with advocacy, analysis, and awareness on some of the most critical topics of international peace and security, including on how to achieve our common, shared goal of a world free of nuclear weapons.”

– Izumi Nakamitsu
UN High Representative for Disarmament Affairs
June 2, 2022
Mina Rozei

Islamic State Group Blamed for Chemical Attack in Syria

April 2024
By Mina Rozei

The Islamic State group likely carried out an attack in Syria using chemical weapons nine years ago, according to international experts responsible for investigating the use of these banned weapons.

Wounded people receive treatment after a mustard gas attack in the Marea district of Aleppo, Syria, on Sept. 1, 2015. An investigation by experts with the Organisation for the Prohibition of Chemical Weapons recently pinned responsibility on the Islamic State group. (Photo by Mamun Ebu Omer/Anadolu Agency/Getty Images)In a report on Feb. 22, the Investigation and Identification Team (IIT) of the Organisation for the Prohibition of Chemical Weapons (OPCW) said that there are “reasonable grounds” to find the Islamic State group culpable for the attack in Marea on Sept. 1, 2015, in which 11 individuals showed symptoms consistent with exposure to sulfur mustard.

“The Secretariat of the OPCW has once again delivered on the mandate it has received to identify perpetrators of chemical weapons use in Syria,” OPCW Director-General Fernando Arias said when the report was released. “This is a stark reminder to the international community that nonstate actors like [the Islamic State group] have developed the capacity and the will to use chemical weapons.”

The report concludes a comprehensive year-long OPCW investigation into the attack in Marea.

Investigators found that the Islamic State group deployed sulfur mustard using one or more artillery guns, asserting that “no other entity possessed the means, motives, and capabilities to deploy sulfur mustard as part of an attack in Marea” on that date.

According to the report, 11 individuals who “came into contact with the liquid substance experienced symptoms consistent with exposure to sulfur mustard.”

The IIT was able to reconstruct the organizational chain of command that led to the attack and identify four individuals as perpetrators and two additional Islamic State members as primary drivers of the group’s chemical weapons program.

Using a finding of “reasonable grounds” to assign the responsibility to the Islamic State group is a “standard of proof consistently adopted by international fact-finding bodies and commissions of inquiry,” the report said.

The IIT relied on interviews, information from the OPCW Fact-Finding Mission, states-parties to the Chemical Weapons Convention (CWC), and various forensic evidence and data to reach its conclusions.

The Syrian Network for Human Rights, a primary nongovernmental organization providing the IIT with on-the-ground information, has documented five chemical weapons attacks by the Islamic State group and 132 casualties since the group emerged in Syria in 2013.

This case marks the first time that the IIT has established that a nonstate actor perpetrated a chemical weapons attack in Syria. Mozambique’s UN ambassador, speaking at a UN Security Council meeting on behalf of Algeria, Guyana, and Sierra Leone, declared that the findings “suggest that, henceforward, the Syrian chemical weapons program will be seen in a different perspective.”

The findings document the latest in a series of confirmed chemical attacks in Syria and underscore growing frustration that CWC states-parties are becoming less compliant with the treaty. “The absence of accountability for the use of chemical weapons continues to be a threat to international peace and security,” said Adedeji Ebo, director and deputy to the UN high representative for disarmament affairs, at a Security Council meeting on March 4.

The findings provoked a mixed reaction at the meeting. Some states, such as the United States, criticized Syria for failing to comply with the OPCW and pointed to the latest IIT report as proof that the OPCW remains impartial. France, Japan, and Slovenia also praised the OPCW’s impartiality and called on Syria to comply with the IIT.

Syria insisted that it destroyed its chemical weapons stockpile and is cooperating with the OPCW. Russia and Iran defended Syria and said the OPCW is being exploited by Western countries.

The IIT report was released before the OPCW Executive Council met in The Hague on March 5-8 where its findings were discussed. Arias reported that Syria’s chemical stockpile declaration continues to have “gaps, inconsistencies, and discrepancies that remain unresolved [and] the Secretariat assess[es] that the declaration submitted by [Syria] still cannot be considered accurate and complete.”

As a result of the 2015 attack, 11 individuals showed symptoms consistent with exposure to sulphur mustard.

Addressing Current Chemical Weapons Convention Compliance Challenges



Tuesday, March 26, 2024
10:00 - 11:00 a.m., U.S. Eastern Time

Although all member states of the 1997 Chemical Weapons Convention have verifiably completed the destruction of the chemical weapons stockpiles as required by the treaty, the regime still faces compliance challenges. Ten years after Syria's massive declared chemical arsenal was removed from its territory and destroyed under international supervision, gaps and inconsistencies in its declaration remain unresolved and several incidents of chemical weapons use have been documented by the Organisation for the Prohibition of Chemical Weapons (OPCW).

Meanwhile, credible allegations have arisen in the past several months that Russia has used riot control agents against Ukrainian infantry position, which would be a violation of the CWC.

A high-level group of panelists discussed these ongoing CWC compliance concerns.

Speakers included:

  • Ambassador Ahmet Üzümcü, former Director-General of the Organisation for the Prohibition of Chemical Weapons (OPCW) will review on the OPCW’s investigations and findings regarding chemical weapons use in the Syrian Arab Republic, and approaches to addressing unresolved issues.
  • Fadel Abdulghany, head of the Syrian Human Rights Network, will discuss ongoing concerns and impacts chemical weapons use on the Syrian people, and the role of civil society in documenting incidents of CWC noncompliance.
  • Ambassador Susannah Gordon, Permanent Representative of New Zealand to the OPCW, will provide an update on new allegations that riot control agents are being used by Russian forces in the war in Ukraine in violation of the CWC, what it means in terms of challenges to the CW, and how CWC member states might respond.

The webinar was be moderated by CWC Coalition Project Coordinator Mina Rozei.

This discussion was on the record. The webinar was organized by the Arms Control Association and the Chemical Weapons Convention Coalition.


Ten years after Syria's chemical arsenal was destroyed under international supervision, gaps and inconsistencies in its declaration remain unresolved. Meanwhile, credible allegations have arisen in the past several months that Russia has used riot control agents against Ukrainian infantry position, which would be a violation of the CWC. In this webinar, a high-level group of panelists discussed these ongoing CWC compliance concerns.


Ukraine Accuses Russia of Using Chemical Agent

March 2024
By Mina Rozei

Ukraine has accused Russian ground forces in Ukraine of multiple instances of using riot control agents against Ukrainian infantry positions this year in a manner prohibited by the Chemical Weapons Convention (CWC).

An example of the K-51 gas grenade that Ukraine accuses Russian ground forces of using in their full-scale war in Ukraine in a manner prohibited by the Chemical Weapons Convention. (State Border Service of Ukraine)Russia used K-51 grenades filled with chloropicrin, a World War I-era chemical substance, 229 times since the beginning of January, according to a Feb. 9 statement from the Armed Forces of Ukraine published via the Ukrainian Army’s Telegram channel.

In a televised statement on Jan. 30, a Ukrainian military spokesperson said Ukraine also has documented incidents from 2023 in which Russia used grenades and drones filled with chloropicrin and more recently with 2-chlorobenzylidene malononitrile gas, commonly known as tear gas, both of which are classified by the CWC as riot control agents.

These agents, which are used widely by domestic police forces around the globe, are banned by the CWC for use by militaries on the battlefield. Article 1 of the treaty specifically obligates states-parties “not to use riot control agents as a method of warfare.”

The spokesperson for Ukraine’s Tavria military group, Col. Oleskandr Shtupun, said on Jan. 30 on Ukrainian national television that each case of alleged use of these agents is being investigated separately. “Appropriate analyses are made, and then the results are submitted to international institutions,” Shtupun said, according to The Kyiv Independent.

The Russian Embassy to the Netherlands denied the charges in a Jan. 26 statement on social media. “All allegations that Russia is using grenades with chloroacetophenone banned by the Geneva Convention are based on unconfirmed data. There are no chemical weapons in the stockpiles of the Russian army, as confirmed by international investigations,” according to the post.

But in November, Mallory Stewart, the U.S. assistant secretary of state for arms control, deterrence, and stability, said that “Russia’s problematic behavior has now expanded to Ukraine.”

Speaking to the CWC conference of states-parties, she noted that “reports shared by our Ukrainian colleagues and aired on Russia’s own state media suggest Russian armed forces are using [riot control agents] against Ukrainian forces.”

“We call on Russia…to immediately and unconditionally withdraw from Ukraine and to comply with its CWC obligations, including refraining from using [these agents] as a method of warfare,” Stewart said.

At the same conference, Ukraine’s representative, Kateryna Bila, said her government is in contact with the Organisation for the Prohibition of Chemical Weapons (OPCW) “on the threat of chemical weapons use and assistance and protection support from the [secretariat] as well as from [CWC] states-parties.”

The OPCW Executive Council will meet March 5-8 in The Hague, but the alleged use of riot control agents in Ukraine is not on the provisional agenda posted by the OPCW secretariat. Russia lost its elected seat on the council in a contentious vote in November.

Using riot control agents in Ukraine is prohibited by the Chemical Weapons Convention, Ukraine said.

U.S. Completes Landmark CWC Destruction

September 2023
By Mina Rozei

After decades of effort, the United States completed the destruction of its vast chemical weapons arsenal and marked the final step in eliminating the world’s known chemical weapons stockpiles.

Operators place the last M55 rocket containing GB nerve agent on a conveyor to begin the destruction process at the Blue Grass Chemical Agent-Destruction Pilot Plant on July 7. This was the last munition destroyed in the declared U.S. chemical weapons stockpile. (Photo by U.S. Army)Apart from the four countries that remain nonsignatories to the Chemical Weapons Convention (CWC)—Egypt, Israel, North Korea, and South Sudan—every nation in the world is now free of its verified chemical weapons arsenals.

Russia and Syria have been accused by the Organisation for the Prohibition of Chemical Weapons (OPCW), which oversees the CWC, and many countries for holding secret stocks and using them against adversaries in recent years.

The CWC prohibits the development, production, acquisition, stockpiling, and retention of chemical weapons.

The main goal of the convention, ratified in 1997, is the verification and destruction of all known chemical weapons stockpiles. The United States declared that it possessed nearly 30,000 metric tons of chemical weapons. Russia declared that it had roughly 40,000 metric tons of chemical weapons in its stockpile, the world’s largest.

When the United States ratified the convention in 1997, it was given 10 years to completely and verifiably destroy its chemical weapons arsenal at its nine military sites. After the United States received two five-year extensions from the OPCW, the final destruction deadline was set for Sept. 30, 2023, for the two remaining sites, at Blue Grass, Kentucky, and Pueblo, Colorado. Although there were doubts about whether this date could be met, the process was completed in July, more than two months early.

U.S. officials worried that adversaries such as Iran, Syria, and Russia would point to the delays as evidence of hypocrisy and undermine the U.S. commitment to eliminating chemical weapons. According to Craig Williams, head of the Kentucky Citizens Advisory Commission at the Blue Grass facility, meeting safety and environmental standards was crucial to the process. “The primary challenge was convincing the military to abandon their selected technology, incineration (with no public input), and implementing an acceptable alternative, neutralization,” he said.

The destruction of all known chemical weapons stockpiles was a turning point in arms control more broadly, not just for the CWC regime. But other serious issues remain. Although Russia is a CWC state-party, questions have been raised about its treaty compliance. Russia’s use of chemical weapons in assassinations and its alliance with the Syrian regime highlight cracks in CWC implementation.

OPCW investigative teams determined that Syria used chemical weapons on multiple occasions between 2013 and 2018 in the Syrian civil war and that Islamic State forces also used them. In addition, four countries still have not joined the treaty.

Meanwhile, new challenges face the Blue Grass and Pueblo facilities and the people who work there. According to Irene Kornelly, head of the Citizens Advisory Commission at the Pueblo site, “The closure of the chemical destruction facility is the biggest issue facing the Pueblo community. The goal is to make this property a viable part of the Pueblo community with jobs and a vibrant economy.”

These accomplishments and challenges will be on the agenda when the 28th conference of CWC states-parties convenes in The Hague on Nov. 27-Dec. 1.

The destruction of the last U.S. chemical weapon marked the final step in eliminating the world’s known stockpiles.  

CWC Review Conference Fails to Achieve Consensus

June 2023
By Mina Rozei

States-parties to the 1997 Chemical Weapons Convention (CWC) failed to agree on a joint outcome document at the conclusion of their fifth treaty review conference May 15-19 in The Hague.

Russia and Syria blocked consensus at the fifth review conference of the Chemical Weapons Convention on May 15-19 because they objected to any mention of Syria’s well-documented chemical weapons use. (Photo courtesy of OPCW)After an opening round of general statements and consultations and more than two days of closed-door debate in the committee of the whole, Russia and Syria blocked adoption of the draft outcome document because they objected to any mention of Syria’s well-documented chemical weapons use. Lacking consensus, the conference ended with a chairman’s report that summarized the week’s proceedings.

Henk Cor van der Kwast of The Netherlands, conference chair, attributed the lack of consensus to a “lack of time” because member states of the Organisation for the Prohibition of Chemical Weapons (OPCW) allowed only one week for the conference.

In a May 20 statement, the U.S. State Department said Russia “repeatedly obstructed these efforts to negotiate in good faith throughout the process and prevented consensus on a final outcome document despite the majority of the issues receiving broad support.” It also noted that “more than 70 delegations, including the United States, joined a statement pledging to advance a positive agenda for the OPCW.”

In January 2023, the OPCW's Investigation and Identification Team (IIT) concluded that there were “reasonable grounds” to believe that the Syrian military dropped two yellow chlorine gas cylinders on two apartment buildings in Douma, Syria, in 2018, killing 43 people and injuring many more. Russia and Syria have claimed that this attack and others attributed to Syria were staged by Syrian opposition forces.

In 2013, following a large-scale attack by Syrian forces on the outskirts of Damascus against rebel-held positions, Syria was pressured to join the CWC, declare its chemical weapons arsenal, and accept a plan developed by Russia, the United States, OPCW, and United Nations to remove and destroy its stockpile of chemical weapons and production capabilities. Since then, the Syrian regime of President Bashar Assad has denied OPCW staff access to inspect its chemical weapons stockpile to verify the completion of the process and the accuracy of its declaration. (See ACT, March 2023.)

Held 25 years after the CWC’s entry into force, the review conference underscored the widespread global support for the treaty and the successful elimination of most of the declared chemical weapons stockpiles once possessed by its states-parties. The United States reaffirmed that it is still on track to complete the destruction of the last remnants of its once vast chemical weapons stockpile before a Sept. 30 deadline.

But the conference also underscored how geopolitical tensions between Russia and many other states are straining the CWC regime. In a statement to the conference, the head of the Russian delegation, Kirill Lysogorskiy, asserted that the 2018 decision authorizing the OPCW Technical Secretariat to identify the perpetrators of chemical weapons use in Syria is “destroying the integrity of the CWC and the credibility of the organization.” He insisted that it “goes beyond the organization’s mandate and encroaches onto the exclusive competence of the UN Security Council.”

Lysogorskiy also reiterated Russia’s rejection of investigations that show that its security forces were responsible for poisoning Kremlin political opponents with banned chemical agents.

A new theme at this conference was the opaque process by which nongovernmental organizations are accepted or rejected for participation at OPCW meetings. There was strong civil society participation in the open sessions, and nongovernmental representatives were allowed to deliver topical presentations to the plenary. But several organizations with relevant expertise and standing were rejected without explanation by the general committee of the OPCW that handles accreditation, raising questions of possible political bias.

Despite the inability to achieve consensus on a final outcome document, OPCW Director-General Fernando Arias emphasized in his closing remarks that the “common ground that was found and national documents that were produced will provide strategic guidance for the tasks that the OPCW will carry out in the future.”


Russia and Syria blocked adoption of the draft outcome document because they objected to any mention of Syria’s well-documented chemical weapons use.  

OPCW Confirms More Syrian Chemical Weapons Use

March 2023
By Mina Rozei

International investigators confirmed a fifth instance in which Syria used chemical weapons against civilians.

Detection equipment used by staff of the Organisation for the Prohibition of Chemical Weapons which has confirmed yet another incident of chemical weapons use by army forces in Syria. (Photo by John Thys/AFP via Getty Images)In a Jan. 27 report, the Investigation and Identification Team (IIT) of the Organisation for the Prohibition of Chemical Weapons (OPCW) concluded that there were “reasonable grounds” to believe that the Syrian military dropped two yellow chlorine cylinders on two apartment buildings in Douma, Syria, on April 7, 2018.

The report found that exposure to the chlorine gas killed 43 people and injured many more. It draws on information gathered by the OPCW fact-finding mission, which had found “reasonable grounds” to believe that chemical weapons were used.

The IIT subsequently was tasked with confirming the mission’s findings, identifying the perpetrators of the attack, and assessing competing claims by Syria and Russia that the attack was staged by Syrian opposition forces.

The team concluded that it has “reasonable grounds to believe that chlorine gas was used at both relevant locations in Douma, and that the cylinders were the origin of the chlorine gas released at both locations.” It refuted claims by the government of Syrian leader Bashar Assad that the attack was staged and that Damascus has not engaged in chemical weapons use.

Using chemical weapons has become something of a pattern for the Assad regime. They were first deployed by army forces in Ghouta in 2013 and twice in Douma in 2018 prior to the April 7 attack.

“These findings are unfortunately not surprising,” Bonnie Jenkins, U.S. undersecretary of state for arms control and international security, told a UN Security Council briefing on Feb. 7. “This is indeed the fifth separate instance of chemical weapons use the IIT has attributed to the Assad regime—all clear violations of the Chemical Weapons Convention [CWC]. These are in addition to the four chemical weapons attacks previously attributed to the Assad regime by the UN’s Joint Investigative Mechanism.”

Jenkins called for “accountability of those responsible for the numerous chemical weapons attacks carried out by the Assad regime, including the one in Douma.”

The Assad regime has denied OPCW staff access to inspect its chemical weapons stockpile several times. At the Security Council briefing, Jenkins again urged Damascus to comply with this treaty obligation.

OPCW Director-General Fernando Arias affirmed that the report corroborates Syrian chemical weapons use while refuting “all other alleged scenarios.”

He cited the high standards followed by the OPCW and its investigative bodies as further validation of their findings.

“The report is now in your hands,” he told the Security Council, adding that it will be up to the UN and the international community to take further steps if deemed necessary.

The case underscores the continued relevance of the CWC, which bans all production, storage, and use of chemical weapons. Although the treaty has been ratified by all but four states since its entry into force in 1997, it faces challenges in ensuring that its provisions are enforced.


Investigators confirmed the fifth instance of CW use against civilians in the Syrian war. 

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