The banned nerve agent sarin has been used repeatedly in the Syrian conflict, as laboratory tests have confirmed. There are disputes, though, about who has been using it. Syrian rebels, along with western governments, blame the Assad regime while the regime, supported by Russia and Iran, blames the rebels.
The regime, by its own admission, had a chemical weapons programme that produced large quantities of sarin, but could rebel fighters have acquired sarin too? If they did, there are three ways they might have got it:
1. By making it themselves
2. By getting it from a foreign supplier
3. By stealing it from the Syrian government
Russian officials have fequently suggested that the sarin used in Syria could be "home-made" and the Syrian president, Bashar al-Assad, has asserted that “anyone can make sarin in his house”. In a similar vein, the American journalist Seymour Hersh, who has written several articles about chemical attacks in Syria, told a CNN interviewer: "It's not hard to make sarin. You can mix it in the backyard – two chemicals melded together."
This gives the impression that all you need is a few pots and pans plus the right ingredients. But it's more complicated than that.
It's true that a chemist, working in a laboratory and taking suitable precautions, could make a tiny amount of sarin without undue difficulty but producing it in the quantities needed for chemical weapons is a very different proposition.
Worldwide, there is only one known example of anyone other than a government manufacturing sarin on a significant scale. This was the Japanese doomsday cult, Aum Shinrikyo, which used sarin to kill 12 people on the Toyko subway and eight others in a separate attack at Matsumoto in the 1990s.
Aum's production methods give some idea of what Syrian rebels would be up against in trying to make their own sarin.
The cult had plenty of money and it spent $10 million setting up a secret factory which was known as Satyan 7 and designed to look like a shrine to the Hindu god Shiva. It is described by Amy Smithson in a study of chemical and biological terrorism:
"The entrance of Satyan 7 was a shrine that disguised the facility’s real purpose. Above a huge styrofoam statue of the head of Shiva was the 'Room of Genesis', chocked with tanks holding nerve gas precursor chemicals. Behind Shiva was a two-storey distillation column.
“Further into the building were three laboratories, a computer control center, and the fabrication area with its five reactors, injectors, piping, wiring, and heating. The equipment was corrosion-resistant Hastelloy, well-suited for making chemical warfare agents.
"The fifth reactor in this suite was state-of-the-art – a $200,000 Swiss-built, fully computerised model with automatic temperature and injection controls plus analytical and record keeping features ... Next door to Satyan 7 was a laboratory that alone cost an estimated $1 million to build, filled with hundreds of thousands of dollars of analytical equipment.
“Satyan 7 had some built-in safety features, such as hatchways that sealed off rooms in the event of accidents, ventilation, and a decontamination chamber. Technicians wore gas masks and full-body chemical suits during certain operations, such as sampling. Closed-circuit television recorded activities in the production area.”
Satyan 7 never came close to its intended production target of two tons a day. According to sources cited by Smithson it produced only 20 litres of sarin over a two-month period in 1994 before something went wrong and it had to be shut down. Twenty litres is less than half what would be needed to fill just one of the rockets used in the 2013 attack on Ghouta in Syria.
After reading Smithson’s report, anyone thinking of making their own sarin in secret might well conclude that it isn’t worth the effort.
Despite all the technology used by Aum, its sarin was not of a very high quality. According to Åke Sellström, the chief UN investigator, the sarin used in Ghouta was not only superior to that used by Aum in Japan but also superior to that used by Iraq in its war with Iran. This strongly suggests it was not home-made but came from some government source.
One of the problems at Satyan 7 was finding the right people to operate it. The cult seemed to have little trouble recruiting young and highly educated scientists and engineers but they lacked practical experience. After the emergency shut-down in 1994, Aum tried to get it running again by seeking out Russian chemical-weapons engineers, but to no avail.
Another problem with trying to make sarin in secret is the noxious waste. One calculation, based on German experience, is that for every ton of sarin produced there will be at least seven tons of waste which would have to be disposed of harmlessly and without attracting attention. Satyan 7 ran into trouble on that account when neighbours complained to police about the unpleasant smells.
Shopping for raw materials
In order to make their own sarin, Syrian rebels would need to obtain the relevant chemicals – and preferably in a way that did not arouse suspicion. Aum did this in Japan by buying them through front companies.
However, the effect of Aum’s attacks was to raise awareness of the threat from chemical and biological terrorism, prompting new efforts to counter it. Anyone trying to buy the ingredients for sarin today would have more difficulty and face a greater risk of being caught than Aum did in the 1990s.
Towards the end of May 2013, police in Turkey arrested 12 people who were said to be connected with the Syrian rebel group Ahrar al-Sham and/or the Nusra Front. Initial reports said they had been caught with 2 kg of sarin (though according to later reports it turned out to be anti-freeze).
Six of the suspects were released almost immediately but the authorities claimed the remaining six – five Turkish citizens and a Syrian – had been trying to buy chemicals to make sarin. They were charged with attempting to acquire weapons for a terrorist organisation and the Syrian, Haytham Qassab, was also charged with belonging to a terrorist organisation.
The timing of the arrests was interesting because it came just a few weeks after first reports of chemical weapons use started circulating in Syria and the government and rebels began accusing each other.
When the case came to trial at the end of 2015, the five Turks were acquitted while Qassab – who had been released earlier and was not in court – was given a 12-year sentence.
Exactly what lay behind this affair is far from clear, partly because the case became politicised. Turkish opposition MP Eren Erdem appeared on the Russian RT channel alleging a cover-up and the government responded by threatening him with treason charges.
However, it does seem that Qassab had been a regular purchaser of military and medical supplies for Syrian rebels. Prosecution documents said he had moved to Antakya in Turkey on the instructions of Abu Walid, leader of the Ahrar al-Sham Brigades. He was quoted as saying:
“After I arrived in Antakya, other rebel groups had come into contact with me. While some had asked me for medicine and other humanitarian aid supplies, others wanted to obtain military equipment.”
According to the Turkish prosecutors, his sarin-related shopping list consisted of the following items:
- Timed fuses
- Chrome pipes
- Thionyl Chloride (SOCl2)
- Potassium Fluoride (KF)
- Methanol (CH3OH)
- Isopropanol (C3H8O)
- Isopropanolamine (C3H9NO)
- White Phosphorus (P4)
- Medical Glucose
To demonstrate a connection between this and sarin, the Turkish authorities proposed a five-step formula:
1. Methanol (CH3OH) + White phosphorous (P4) = Dimethylmethylphosphonate (DMMP)
2. DMMP + Thionyl Chloride (SOCl2) = Methylphosphonyldichloride (DC)
3. DC + Potassium Fluoride (KF) = Methylphosphonyldifluoride (DF)
4. DF + Isopropanol (C3H8O) = Sarin (C4H10FO2P) + Hydrogen Fluoride (HF).
5. Add Isopropanolamine (C3H9NO) to neutralise the corrosive HF.
Whether that would actually result in sarin is a matter of dispute. Dan Kaszeta, a security consultant with experience in chemical weapons, says:
"This hasn’t even been cribbed from easily available documents on the internet. Indeed, I cannot rule out that an obviously fake recipe has been circulated for purposes of deception or mischief. If I wanted to write a recipe for sarin that looked broadly correct, but which would never result in any actual sarin (or even harm the producers) it is the sort of thing I would do."
Kaszeta explains his reasoning here. Others have expressed different views (here and here) but there does seem to be agreement that if rebels were trying to buy isopropanolamine they had got the name wrong and should probably have been looking for isopropylamine instead.
At its most incriminating, the Turkish case indicates an attempt by rebels to acquire precursors for sarin. It does not show they had an ability to make it, and there is no evidence they had acquired the necessary equipment.
It’s also worth noting that two of the chemicals on the shopping list cannot be bought in Turkey without government approval, so if Qassab went looking for them there was a fairly high chance of being caught. This suggests another possibility – that Qassab might have been set up for entrapment by agents working for the Syrian government or perhaps even the Turkish government.
Instead of trying to make their own sarin, an alternative course for Syrian rebels would be to seek out ready-made supplies from abroad. This was something the Japanese Aum cult had initially tried (and failed) to do before deciding to manufacture it. Aum contacted what it thought was a rogue operation in the United States illicitly selling nerve gas but its would-be supplier turned out to be an undercover arm of the US Customs Service.
The Syrian and Russian governments have both encouraged the notion of rebel fighters receiving sarin from abroad but have not been forthcoming with any details. In 2014, following discussions with the Syrian authorities, Åke Sellström, the chief UN weapons inspector in Syria, said: “They have quite poor theories: they talk about smuggling through Turkey, labs in Iraq.” The lack of any supporting evidence puzzled Sellström:
“To me it is strange. If they really want to blame the opposition they should have a good story as to how they got hold of the munitions, and they didn’t take the chance to deliver that story.”
Among the suggested foreign sources for rebel sarin, neighbouring Iraq, with its porous border, is perhaps the most obvious. ISIS is active on both sides of the border and is known to have used chlorine and mustard gas as chemical weapons.
In the Iraqi city of Mosul last September, American warplanes bombed what was said to be “a chemical weapons production facility” which also served as an ISIS headquarters building.
According to news reports the building was a converted pharmaceutical factory. But it does not appear to have been producing sarin and there have been no reports of ISIS using sarin in Iraq.
Video of the US-led airstrike on the alleged chemical weapons factory operated by ISIS in Mosul, Iraq
Last November, John Dorrian, a US military spokesman in Iraq described ISIS's ability to use chemical weapons as “rudimentary”. He told the New York Times typical weapons used in these attacks were rockets, mortar shells or artillery shells filled with chemical agents which had little effect beyond the immediate area where they landed.
Around the same time a report by IHS Conflict Monitor said the “most likely” chemical threat emanating from ISIS in Mosul was from chlorine and mustard agents. There was also, “to a much lesser extent”, the possibility of a “dirty bomb” in which radioactive materials seized from hospitals could be scattered using conventional explosives. The report gave no indication that ISIS was producing sarin in Mosul and, even if had been doing so, that would not explain why sarin attacks in Syria began in 2013, since ISIS did not capture Mosul until June 2014.
But could ISIS have obtained sarin left over from the Saddam Hussein era? Also in June 2014 – again, too late to account for the earliest sarin attacks in Syria – ISIS overran a disused chemical weapons facility at Muthanna, north-west of Baghdad, and began looting it.
One section of this complex, Bunker 13, contained 2,500 sarin-filled 122mm chemical rockets which had been produced and filled before the 1991 Gulf war. However, both the UN and US insisted these weapons were not in a usable state. The UN said the bunker had been bombed during the Gulf war, and the rockets were "partially destroyed or damaged". US state department spokeswoman Jen Psaki said the bunker contained "degraded chemical remnants". There were no “intact chemical weapons” and it would be “very difficult, if not impossible, to safely use this for military purposes or, frankly, to move it".
In an article for the London Review of Books, Seymour Hersh, the famous but controversial American journalist, claimed the Obama administration had been involved in setting up a “rat line” – a back channel route for transferring weapons from Libya to rebel fighters in Syria. Hersh wrote:
“The rat line, authorised in early 2012, was used to funnel weapons and ammunition from Libya via southern Turkey and across the Syrian border to the opposition. Many of those in Syria who ultimately received the weapons were jihadists, some of them affiliated with al-Qaida.”
The inference from Hersh's article, since it talked extensively about chemical weapons in Syria, was that sarin could have been among the weapons allegedly sent to Syria from Libya – and numerous websites were quick to pick up on that.
One internet article – for Global Research, a website that specialises in conspiracy theories – began:
“Hersh didn’t elaborate as to whether the 'arms' he referred to encompassed the chemical precursors for creating sarin gas, which Libya stockpiled. However, multiple independent reports have independently confirmed that Gaddafi of Libya did, indeed, possess such stockpiles.”
Needless to say, the US denied Hersh's claim of a “rat line”. A spokesperson for the Director of National Intelligence quoted in his article said: “The idea that the United States was providing weapons from Libya to anyone is false.”
Even if the story of a “rat line” were true, it's difficult to see how sarin could have been among any weapons sent to Syria. The Gadafi regime may have dabbled with making sarin but there's no evidence of production on an industrial scale. The most that Syrian rebels could conceivably have got from Libya was precursor chemicals which would then need processing.
Libya became a party to the Chemical Weapons Convention in 2004 and the lengthy process of dismantling its stockpiles and production facilities got under way. The Organisation for the Prevention of Chemical Weapons (OPCW) reported that Libya had declared possession of about 25 metric tonnes of sulfur mustard and more than 3,500 chemical munitions in the form of unfilled aerial bombs. It also declared nearly 1,400 metric tonnes of “precursor chemicals that could produce more lethal weapons like the nerve agent sarin”, as well as three chemical weapons production facilities.
By the time of the 2011 uprising some 40% of the precursors had been destroyed, leaving about 850 tonnes still to be disposed of. These were stored at Ruwagha – a remote spot in south-eastern Libya. Last year, amid fears that ISIS could attack the site, the remaining chemicals (by then reduced to 500 tonnes) were shipped out of Libya under supervision by the Organisation for the Prohibition of Chemical Weapons (OPCW).
The upshot of this is that Syrian rebels could not have obtained sarin precursors from the declared stocks in Libya. Any that they did obtain would have to have come from undeclared stocks that had lain undiscovered for years, and any actual sarin produced in Libya before its chemical weapons programme was dismantled would not be in a usable state today.
One further theory is that Saudi Arabia provided Syrian rebels with sarin-filled weapons. This doesn't bear much scrutiny but it should probably be mentioned because Russia promoted it for a while and even suggested the UN should investigate it.
The claim first surfaced in August 2013, eight days after sarin attacks killed hundreds of people in opposition-controlled Ghouta on the outskirts of Damascus.
An article for Mint Press, a US-based website, claimed Saudi Arabia had provided rebels with some chemical weapons but without telling them what they were or how to use them. According to the story, the deaths in Ghouta were a result of these rebels handling the weapons “improperly”.
This appears to have been based on a rumour circulating in Damascus at the time but it was nonsense. Shortly afterwards, a report from the UN by inspectors concluded that chemical weapons had been used against civilians in the area “on a relatively large scale”. It continued:
“The environmental, chemical and medical samples we have collected provide clear and convincing evidence that surface-to-surface rockets containing the nerve agent sarin were used in Ein Tarma, Moadamiyah and Zamalka in the Ghouta area of Damascus.”
The report also gave details of a particular kind of rocket used in the attack. This was of a type previously photographed in use by Syrian government forces with a non-chemical warhead. Searches for photographs of the same rocket in rebel hands drew a blank.
A third option for the rebels – and perhaps more attractive than making their own sarin or importing it – would be to capture some from the Syrian government's stocks. As it happens, there is one published claim of them doing so.
In December 2012 jihadi fighters captured a large Syrian army base near Sheikh Suleiman in Aleppo province and began plundering it for weapons. One of the participants, a fighter named Abu Ahmed later said they had found chemicals there – including sarin.
Abu Ahmed's story is recounted by journalists Harald Doornbos and Jenan Moussa in an article for Foreign Policy:
They found large stocks of weapons, ammunition and, to their surprise, chemical agents. They were, according to Abu Ahmad, mainly barrels filled with chlorine, sarin, and mustard gas.
What followed was the distribution of the war spoils. Everybody took some ammunition and weapons. But only the Nusra Front seized the chemical weapons. Abu Ahmad watched as the al-Qaeda affiliate called in 10 large cargo trucks, loaded 15 containers with chlorine and sarin gas, and drove them away to an unknown destination. He did not see what happened to the mustard gas.
Abu Ahmed later suspected the chemicals had ended up in the hands of ISIS. Doornbos and Moussa continue his story:
Out of the blue, Abu al-Atheer, the man to whom Abu Ahmed had pledged loyalty – and who had in turn pledged loyalty directly to Baghdadi [the "Caliph" of ISIS] – told his own commanders that ISIS had twice used chemicals during attacks against the Syrian Army. The announcement came during a normal conversation between Abu al-Atheer and his men; the ISIS commander told the story happily and proudly.
“The brothers sent a car bomb with chemicals to a [Syrian Army] checkpoint near al-Hamra village in Hama,” Abu al-Atheer claimed, as they sat in their headquarters ...
Abu al-Atheer spoke of another ISIS chemical attack. “We also used one car bomb filled with chemicals against regime forces near to Menagh Airbase,” he said ...
Again, Abu Ahmed thought back to that cold December day when jihadi fighters overran Regiment 111 [at Sheikh Suleiman]. Were these the same chemical weapons that he and his comrades had found stockpiled in the base back then?
Although Abu Ahmed is the only source for this story there's no particular reason to suppose he didn't believe what he was saying. It's possible that fighters did seize some chemicals. The question is how they knew that sarin was among them.
Whatever chemicals the “barrels” contained, it’s almost certain that sarin was not one of them – at least, not in a ready-to-use form. Sarin degrades quickly in storage and the Syrian government had got around that problem by keeping it in binary form – as two separate liquid components – which have to be mixed to make it active.
So, if rebels did seize binary sarin from government stocks it would be useless unless they knew that it was in two parts, unless they knew how to mix it and fill munitions with it – and had suitable equipment for doing so. The Syrian government had eight mobile mixing-and-filling stations specially for this purpose, according to its declaration to the OPCW.
Judging by Abu Ahmed's account, the jihadis also seem to have had rather unsophisticated ideas about what to do with captured chemicals – such as combining them with car bombs. If sarin was used in this way it would almost certainly be destroyed by the bomb before it could poison anyone.
There is, however, one very big problem with Abu Ahmed's story. Up to the point when the OPCW moved in to dismantle Syria's chemical weapons, the Assad regime was insisting that none of them had been lost or captured.
Interviewed in 2014, Åke Sellström, the chief UN weapons inspector in Syria, said:
"I asked them, pointedly, what about your own stores, have your own stores being stripped of anything, have you dropped a bomb that has been claimed, bombs that can be recovered by the opposition? They denied that."
Clearly, the regime had an interest in seeing rebels – rather than itself – blamed for the sarin attacks. If its stocks had been plundered, saying so would have helped to shift suspicion towards the rebels. There was no obvious reason to lie by denying it.
The result of this is an odd situation where the two least likely ways rebels might have got sarin – by making it or importing it – are the two most often proposed by the regime and its allies. Meanwhile the one that might have more plausibility – seizure of government stocks – is the one the regime flatly rejects.
There is good reason to believe that sarin used in Syria did come from government stocks, and the clue to this is hexamine.
The Syrian government is known to have been using hexamine in its chemical weapons programme, because it declared 80 tonnes of the substance to OPCW inspectors.
It appears that the Syrian government was adding hexamine to its sarin as an acid scavenger, to counter the corrosive effect of hydrogen fluoride in the mixture. This also seems to have been a uniquely Syrian contribution to chemical warfare, since there is no publicly-available record of other governments using hexamine in sarin production.
Numerous samples from the scene of attacks in Syria have tested positive for hexamine along with sarin – suggesting that the sarin had come from government stocks.
There is some dispute about that conclusion because hexamine in the samples could, conceivably, have come from background sources such as certain types of paint, cooking fuel or possibly RDX explosive. However, that explanation is rather improbable considering the number of hexamine-positive samples from different locations.
The French government also claims to have definite evidence of hexamine in an unused sample of sarin from Syria. In a declassified intelligence assessment published last April it said it had obtained an unexploded sarin grenade dropped from a regime helicopter over Saraqeb in 2013. Chemical analysis, it said, had revealed about 100ml of sarin with hexamine included in the mix.
This, of course, does not prove that all sarin used in Syria contains hexamine – though hexamine was certainly detected at the scene of the two most deadly attacks, at Ghouta in 2013 and Khan Sheikhoun in April this year. The detection of hexamine there makes it far less likely that the sarin involved had been imported from abroad or manufactured by rebels (and it's worth recalling that the Turkish formula that rebels were allegedly using did not include hexamine).
If rebels did manage to acquire sarin and use it in Syria, how they might have got it is only one part of the story. They would also need the ability to use it – which means suitable munitions plus enough expertise to handle and launch them.
To have carried out the 2013 attacks in Ghouta, for example, they would need to have captured the right kind of rockets from government forces, along with their launch vehicle and one of the government’s eight mobile mixing and filling units.
And if, as witnesses say, sarin has been dropped from the sky in at least two attacks, they would also need an air force.