In April last year Syrian opposition groups claimed that the Syrian government had launched a chemical attack in the last opposition stronghold near Damascus. The US, France and Britain responded with a shower of cruise missiles against Syria. Now a leaked report by engineers from the Organization for the Prohibition of Chemical Weapons who investigated the incident says that the alleged chemical attack was staged: the “only plausible explanation” for the gas cylinders found in two apartment buildings was that they were placed there, not dropped from helicopters.
On 8 April last year the world woke up to horrifying images of the bodies of more than 30 dead civilians lying in an apartment building in the Damascus suburb of Douma. The opposition had held out against the Syrian Army till then, but agreed to be evacuated the next day. A week later, the US, France and Britain attacked Syria with more than 100 cruise missiles in retaliation. Theresa May told the House of Commons that:
A significant body of information, including intelligence, indicates that the Syrian regime is responsible for this latest attack. … No other group could have carried out this attack. The opposition do not operate helicopters or use barrel bombs.
A team of investigators from OPCW arrived in Damascus on a Fact-Finding Mission the day after the US-led missile attack, and began inspecting the sites of the alleged attack. In March this year, the Final Report of the Fact-Finding Mission was published. This reported that outside experts in ballistics, structural engineering and metallurgy had been asked to give opinions on “the trajectory and damage to the cylinders”, and concluded that there were “reasonable grounds that the use of a toxic chemical as a weapon took place.“
There was no mention in the Final Report that the Fact-Finding Mission had conducted its own engineering study, led by one of OPCW’s most senior inspectors, Ian Henderson. Now a copy of the suppressed Engineering Assessment has been leaked from inside OPCW – and OPCW has reluctantly confirmed that the document is genuine. Although OPCW has refused to comment further, several UK commentators have reported that their contacts in OPCW briefed them off the record that this was “a minority opinion”, that the author was “on the sidelines”, or a “disgruntled employee”.
The Engineering Assessment says that the cylinder found lying over a hole in the roof (at what they designate location 2) would have punched straight through the roof if it had been dropped from 500M – much lower than a helicopter would actually fly – and could not have been stopped by the steel reinforcing bars without leaving marks on the cylinder. The cylinder with fins found lying on a bed (at location 4) could not have fitted through the hole in the roof if it had been dropped from the sky.
In each case the alternative hypothesis [that the cylinders were placed in position rather than dropped from the air] produced the only plausible explanation for observations at the scene.
Piers Robinson, convenor of the Working Group on Syria, Propaganda and Media  that published the leaked document, says:
“It’s hard to see how the opinions of outside experts who had not been to the sites could override the opinions of OPCW’s own engineering team who had made their own inspection on site. The best way for OPCW to clear this up would be to make all the documents that were used to prepare the Final Report of the Fact-Finding Mission, including the full reports provided by outside experts, publicly available for review.”
David Miller, a member of the working group, stated that:
“this leak shows that there is significant dissent inside the OPCW. We hope that others will come forward with further elements of the story on how the OPCW has performed its role in this and other alleged chemical attacks. It is essential to note that any such disclosures can be done in confidence.”
For further information
Dr Piers Robinson: +44 7764763350, email@example.com
David Miller, Professor of Political Sociology, University of Bristol, +44 7786 927551, firstname.lastname@example.org
For independent comments
A military expert who has read the report (but is not associated with the Working Group):
Jonathan Shaw (former head of UK Special Forces)
For a UK government view
For OPCW’s position
The Public Affairs Office is unlikely to respond (see below). The Chief of Cabinet (equivalent to CEO) is a French diplomat named Sébastien Braha:
 In response to enquiries about this story from journalists, the OPCW Public Affairs office issued a statement on 16 May. The final paragraph was:
Pursuant to its established policies and practices, the OPCW Technical Secretariat is conducting an internal investigation about the unauthorised release of the document in question. At this time, there is no further public information on this matter and the OPCW is unable to accommodate requests for interviews
 Dr Piers Robinson is convenor of the Working Group on Syria, Propaganda and Media, and co-author of the group’s previously published briefing notes on the Douma incident and other alleged chemical attacks in Syria. The group was attacked by The Times in April 2018 as ‘Assad apologists” for questioning the evidence on these alleged chemical attacks and the role of the White Helmets. The Working Group has never expressed any opinion in favour of or against the Syrian government.
 Professor Miller is a member of the working group and co-author of the group’s previously published briefing notes on the Douma incident and other alleged chemical attacks in Syria.