Syria's Khan Sheikhoun chemical massacre: proof beyond doubt who is to blame
United Nations investigators confirmed this week what most of the world already knew - the Syrian regime almost certainly carried out a chemical attack on an opposition village earlier this year.
The report was presented to the United Nations Security Council earlier this week by the OPCW-UN's Joint Investigative Mechanism after months of research by experts.
The 39-page document was leaked on Friday and detailed the compelling facts behind the panel's conclusion that Damascus carried out April's chemical attack, which left scores of civilians dead.
It also discredits the various myths peddled by the Syrian regime and Russia who have tried to effectively put the blame on the victims or cast doubts about who was responsible for the killings.
"Based on the foregoing, the Leadership Panel is confident that the Syrian Arab Republic is responsible for the release of sarin at Khan Sheikhoun on 4 April 2017," the report confidently concluded.
What Syrians now want to know is what - if anything - will the UN do next with the evidence?
The attack
On 4 April, reports emerged of a noxious gas swamping the opposition village of Khan Sheikhoun in southern Idlib province.
Witnesses heard aircraft overhead and then the sound of an explosion at around 6:30am.
A "yellow mushroom cloud" erupted and a foul - toxic - smell engulfed the air. It soon became evident that Khan Sheikhoun had been targeted with a deadly nerve agent from the air.
Footage showed children and other civilians choking to death, while medical workers worked through the day to save some of those affected. In the end, at least 92 people died, perhaps more.
With little doubt about the perpetrator, the US fired cruise missiles at the Syrian regime airbase of al-Shayrat in Homs province.
Washington said the airfield was targeted due to intelligence indicating al-Shayrat was the launch pad for the attack, although Russia was warned beforehand to allow aircraft and personnel to leave the base unharmed.
Background
Although most of the world was left with little doubt who carried out the attack, various conspiracy theories have been offered by Russia, the Syrian regime, and their supporters.
Much of it hinged on the idea that Damascus had given up its chemical weapons following earlier deadly sarin attacks on civilian areas in Ghouta in 2014, and which nearly resulted in US air strikes during a delicate time for the regime.
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The Leadership Panel is confident that the Syrian Arab Republic is responsible for the release of sarin at Khan Sheikhoun. | ![]() |
The Syrian regime agreed to the handover of the 100 tonnes of toxic materials in its possession to the Organisation for the Prohibition of Chemical Weapons (OPCW).
Despite the UN hailing the "surrender" of the chemical arsenal as a success, the process was based on trusting that the regime had given up all its weapons. Few in the opposition believed that the regime would willingly hand over all its stockpiles and that some had been kept secretly in reserve.
Even the OPCW could not declare Syria to be "free of chemical weapons".
This public exercise was used by the Syrian regime as "proof" it no longer had such an arsenal and could not be blamed for further chemical attacks in Syria.
Conspiracy theories
The Syrian regime has consistently maintained that it did not carry out the nerve gas attack on Khan Sheikhoun and blamed the rebels.
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Yet Damascus' claims have been contradictory, perhaps designed with the intention to sow doubt among the public rather than trying to offer a plausible alternative theory.
The tactic appeared to have some success with leading political figures reluctant to blame the regime. UK opposition leader Jeremy Corbyn said at the time "fingers are pointing [the Syrian regime carried out the attack], yes, but let's get the proof from the United Nations first".
The Labour leader did, however, condemn the US air strikes on an empty air field later, which likely led to zero casualties.
The idea put forward that it was too early to draw conclusions could have led to a delay retaliatory military action from US allies.
Most US policy makers were convinced there needed to be a swift warning to Damascus that further chemical attacks would not be tolerated - although "conventional" Russian and regime bombing were allowed to continue.
Getting the story wrong
Pro-regime media and officials altered their stories about Khan Sheikhoun on several occasions and details given generally did not fit the sequence of events on 4 April.
Bashar al-Assad denied all responsibility and said Khan Sheikhoun was manufactured by the US as a pretext for the attack on al-Shayrat base.
As for the video evidence that a nerve agent was used, Assad shocked Syrians by claiming the footage that horrified the world was fake.
"You have a lot of fake videos now… We don't know whether those dead children were killed in Khan Sheikhoun. Were they dead at all?"
Other theories put forward by the regime were that the rebels exploded sarin stockpiles (even Damascus couldn't claim the opposition had an air force to carry out an aerial assault) to gain sympathy from the world and encourage US intervention.
Anonymous sources also told media that regime aircraft did bomb a site "used to manufacture rockets" in Khan Sheikhoun on that day, but the missiles struck a secret rebel chemical manufacturing site.
This led to the highly publicised theory put forward by Pulitzer Prize winning journalist Seymour Hersh based on a US intelligence "source" that a regime guided missile strike hit a "medicines and chlorine-based decontaminants" storage site - causing the eruption of toxic gases. This has since been thoroughly discredited.
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The sarin identified in the samples taken from Khan Sheikhoun was found to have most likely been made with a precursor (DF) from the original stockpile of the Syrian Arab Republic. | ![]() |
What we know
The UN report follows earlier investigations that concluded sarin was found in the environment of Khan Sheikhoun shortly after the attack. Other investigations also stated that the Syrian air force was almost without doubt to blame for the Khan Sheikhoun massacre.
France, Turkey and the UK have also blamed Damascus and said sarin was used. Ankara had access to air samples carried out of Syria by activists.
Independent investigators such as Bellingcat have also concluded that sarin was used and Damascus was to blame.
The most recent UN report was damning in its assessment of the possible "alternative" theories put forward by the regime and leaves no doubt who should be held accountable for the massacre.
"The sarin identified in the samples taken from Khan Sheikhoun was found to have most likely been made with a precursor (DF) from the original stockpile of the Syrian Arab Republic," it read.
It also dismissed the idea that the chemicals were ignited by a bomb on the ground.
"The crater [at the site] was caused by the impact of an aerial bomb travelling at high velocity," it said.
"Sarin reportedly continued to be present at the site of the crater ten days after the incident indicate that a large amount of sarin was likely released, which is consistent with it being dispersed via a chemical aerial bomb."
Earlier in the report, the investigators claimed the lack of damage to surrounding buildings and the impact of the explosion also made it clear a bomb was dropped from the air.
Investigators were convinced Syrian regime aircraft were overhead Khan Sheikhoun between 6:30am and 7am, when the attack took place, despite the air force denying this.
It also concluded that the sarin used matched samples taken from the stockpiles handed over by Damascus to the OPCW.
"In light of the marker chemicals identified in the (sarin precursor methylphosphonic difluride) DF and the sarin, which are believed to be unique, the Mechanism concludes that the precursor chemical DF - which is necessary to produce binary sarin - is very likely to have originated from the Syrian Arab Republic."
Perhaps most chilling were the medical reports that also pointed to the use of a nerve agent and detailed the victims final agonising moments alive.
Although the report will not bring back the dead it should help the world understand - without doubt - who was responsible for the killings.
It should also shame the liars who have peddled "alternative facts" about that dreadful day when men, women and children died in the most horrific way.