New evidence supports the conclusion that Syrian government forces have used nerve agents on at least four occasions in recent months: on April 4, 2017, in a chemical attack on Khan Sheikhoun that killed at least 90 people, and on three other occasions in December 2016 and March 2017. 

When the UN Security Council meets this week to discuss chemical weapons use in Syria, its 15 members should send a strong message to the Syrian government that those responsible for dozens of chemical weapon attacks will be held accountable and may face future prosecution. It should do so first by imposing sanctions on people suspected of involvement in the illegal use of toxic agents, which have killed hundreds of Syrians and seriously injured many more.

By failing to hold those responsible for these appalling crimes accountable, the Security Council has effectively given perpetrators a green light to deploy sarin and other nerve agents, as well as mustard or chlorine gas against men, women and children.

Russia has used its Security Council veto 11 times to shield its allies in Damascus from condemnation, sanctions or referral to the International Criminal Court. Most recently, Russia vetoed renewing a joint investigation of the UN and Organisation for the Prohibition of Chemical Weapons (OPCW), whose job it was to identify the culprits behind chemical attacks.

The UN-OPCW Joint Investigative Mechanism (JIM) had accused both the Syrian government and Islamic State (also known as ISIS) of repeatedly using illegal chemical agents. In October, the JIM found the Syrian government responsible for the April 2017 sarin gas attack at Khan Sheikhoun that killed dozens, mostly women and children. This echoed Human Rights Watch’s findings.

Russia has in the past taken positive steps urging Syria to change. In 2013, Russia helped pressure Syria to accede to the Chemical Weapons Convention and begin dismantling its chemical weapons program, and Moscow played a key role in establishing the JIM in 2015. But this time around, Moscow has helped Syria’s government evade responsibility for Khan Sheikhoun, alleging that armed groups carried out the attack themselves but offering little evidence to support this claim.

The Russian government should change course, and support UN Security Council in holding those responsible for chemical attacks accountable. Even if it does not, UN members should continue to fund other UN investigative teams established to investigate crimes in Syria and ferret out those responsible for the chemical attacks.

If perpetrators know that evidence of their crimes is being gathered for future prosecution, that may make them think twice before launching another bomb filled with sarin.