The Chemical Weapons Convention (CWC) came into effect on 29 April 1997. 193 Member States of the United Nations have ratified it. The Organisation for the Prohibition of Chemical Weapons (OPCW) is the United Nations body charged with the task of monitoring compliance with the CWC. It is based in The Hague. Among its powers are the powers to investigate allegations of the use of chemical weapons, and (since June 2018) the power to assign blame.
The investigations are carried out by a Fact Finding Mission, which compromises a team of experts from the relevant scientific disciplines. Additional technical assistance is frequently sought from bodies external to the OPCW, typically university departments.
The use of chemical weapons, apart from being banned under the CWC, can constitute war crimes and/or crimes under the civil jurisdiction of the country where they are used. As with any forensic examination of a crime scene, the integrity of the investigation process and any conclusions reached must accord with the highest standards of professional practice.
The work of the OPCW has had a high profile in the past two years because of three well-publicized incidents. The first of these was the alleged use of sarin gas in the Syrian town of Khan Shaykun on 4th of April 2017.
Less than one week after the alleged attack, the United States government released his own intelligence report in which they expressed their “confidence” that the Syrian ‘regime’ had used sarin against its own people. On this unsourced and uninvestigated, much less forensically examined incident, the United States launched a barrage of cruise missiles against Syrian targets. That this response was itself a gross violation of international law was barely considered by the mainstream media at the time, so content were (and are) they in demonizing the Syrian government and in particular its President Bashar al Assad.
The OPCW report of the incident was no better than the US intelligence estimate. Without having visited the site, and without meeting minimum forensic standards such as determining a proper chain of custody, the OPCW in its October 2017 report nonetheless attributed the release of sarin gas to the Syrian government.
The second incident to receive wide publicity, expressions of outrage from western governments and large-scale expulsion of Russian diplomats,