The Syrian authorities say they have detained 18 people on suspicion of involvement in the chemical weapons programme of the former Assad regime. News of the arrests — disclosed by Syrian diplomat Mohamad Katoub in an interview with Reuters news agency on Tuesday — is a significant development.

While Assad remained in power there was little or no prospect of bringing the perpetrators of chemical attacks to justice but there’s now reason to hope that some of them, at least, will be held accountable.

Katoub, who is Syria’s permanent representative to the Organisation for the Prohibition of Chemical Weapons (OPCW), did not name any of the suspects but said they included high-level military, political and technical officials. Several ​had served as major generals under the Assad regime and at least four are on European, UK or US sanctions lists, he added.

This follows a meeting on May 7 between Fernando Arias, the OPCW director-general, and Mazhar al-Wais, the Syrian justice minister, where they agreed to “continue strengthening cooperation” and al-Wais talked of a need to “ensure justice for victims through national accountability processes”.

Katoub told Reuters the Syrian authorities had also located remnants of Assad’s clandestine chemical weapons programme, including raw materials and munitions similar to those used to carry out deadly gas attacks. The Reuters report continued:

Syrian teams, working for months with OPCW ‌inspectors, ⁠located more than 70 rockets and aerial bombs, as well as raw ingredients for the production of sarin, a nerve agent used by Assad’s forces in attacks that killed more than 1,300 people in the Damascus suburb of Ghouta in August 2013 and Al-Lataminah in March 2017, Katoub said.

Chemical weapon mixing and storage equipment and hexamine, a stabilisation agent known to have been used by Assad’s forces in ​sarin production, were also found ​during searches at three locations.

“Despite ⁠the secrecy, the danger, and the immense security challenges … today we delivered for the Syrian people and for the world,” Katoub said. “It is the first time such munitions could be recovered before they were ​used in crimes against the Syrian people.”

These claims are broadly in line with discoveries previously mentioned or hinted at by the OPCW in its monthly progress reports and Katoub appears to have cited them to emphasise the extent of the Syrian authorities’ cooperation. Willing as they may be, though, the authorities’ ability to cooperate is somewhat limited — especially regarding the extent of the former regime’s chemical weapons activity.

Syria joined the Chemical Weapons Convention in 2013 under international pressure after being blamed for a nerve agent attack which killed hundreds in rebel-held Ghouta.

Under the Convention’s rules Syria then had 30 days to declare all its chemical weapons and related facilities but the declaration produced by the Assad regime was far from complete. Twelve years later, and after several amendments, the OPCW is still refusing to certify it, citing 19 “outstanding issues”.

After Assad’s fall, legal responsibility for providing a complete declaration passed to the new authorities in Damascus who then informed the OPCW that they did not “have the knowledge needed to identify what elements of the Syrian chemical weapons programme have not been declared”.

As a result of that, other countries have offered assistance through the “Breath of Freedom Task Force” established in March. It is described as led by Syria but with support from Canada, France, Germany, Qatar, Türkiye, the UK and the US. According to the OPCW, it will have two particular aims:

1- Enable all aspects of the Government of the Syrian Arab Republic and the Organization for the Prohibition of Chemical Weapons’ mission to discover, secure, and verifiably destroy any remnants of Chemical Weapons and related materials and infrastructure that may be found; and,

2- Solicit and provide contributions, consistent with all applicable laws, to build the national capacity of Syria’s Government, to deliver training, equipment, and support execution of the required operations.

Meanwhile Russia, which has consistently sought to muddy the waters over chemical attacks in Syria and undermine OPCW investigations, has resumed its usual antics. In a letter to the OPCW apparently alluding to the creation of the Breath of Freedom Task Force, it complains of British “interference”:

It is expected that within the framework of these efforts, London primarily intends to destroy evidence of the involvement of Western countries in the former Syrian chemical weapons programme and the numerous chemical provocations against the government forces of the Syrian Arab Republic under President Assad, while simultaneously fabricating evidence of Russia’s alleged “cover-up” of the use of chemical weapons attributed to official Damascus at that time.

In these upcoming activities, the British experts will go to the Syrian Arab Republic ahead of the OPCW mission staff in order to prevent them from accessing documents unveiling the participation of companies from Western countries, primarily from the United Kingdom, in shipments of equipment and chemicals for the purposes of the former Syrian chemical weapons programme, and the involvement of the special services of the United Kingdom in the construction, oversight, and financing of the White Helmets non-profit organisation, which was directly involved in the orchestration of chemical provocations on the territory of the Syrian Arab Republic.

The letter ends by repeating previous Russian claims that the novichok poisoning of Sergei and Yulia Skripal, plus the “sham” poisoning of Russian dissident Alexei Navalny were the work of the British government.