Chemical Attacks in Syria: is Assad responsible?

The use of chemical weapons on 4th April in Syria, which prompted the American bombing of an airfield, was blamed on Syrian government forces by the US and UK.[1]

UK ambassador to the UN, Matthew Rycroft, has stated scientists at Porton Down ‘have analysed samples obtained from Khan Shaykhun’, the site of the incident, and ‘these have tested positive for the nerve agent Sarin, or a Sarin like substance.’[2]

This prompts a simple question. Given that the Russians, amongst others, are disputing the UK/US assessment, why not present them with the evidence as revealed in analysis?

The Russians may not take our government’s word for it, but I think they would trust Porton Down scientists. Scientists in Russia and UK (and USA as well) tend to trust each other, I believe, and confer too.

It is worth keeping this background in mind.  Although not mentioned much in our press, tests showed that the 2013 chemical attacks could not credibly be blamed on Assad’s forces.[3] President Obama had been all set to bomb Syria when, at the 11th hour, General Dempsey, Chair of the Joint Chiefs of Staff, who knew of the true state of intelligence, had a word with him.[4] Obama called off the bombing, apparently mindful that congress would be apprised of the intelligence.[5]

The Americans and Russians and Syrians went on to defuse the situation by agreeing on the destruction of Syria’s stockpile of chemical weapons. So even if those stocks had ever been used in the past – which Syria denies – they could not be used in the future. Still, just to be sure, the exact molecular profile of the chemicals was ascertained and recorded at the time.

So, about the present controversy: if there is evidence that Assad was behind the recent Khan Shaykhun incident, then Porton Down scientists have it.

At least, they will, if they have indeed analysed soil samples gathered by rescue workers  from the scene of the 4th April attack, as claimed.[6] For the scientists can obtain the complete chemical profile of a chemical agent, including impurities that are present at very low concentrations, when the sample comes from the soil. They can determine how the sarin was synthesized and whether the sample matches the ‘kitchen sarin’ used by opposition fighters in 2013 or the military-grade sarin from Syria’s former stockpile.[7]

The strange thing, however, is that the UK’s ambassador Rycroft has spoken of the sample containing a ‘sarin-like substance’. Analysis of a sample molecule identifies it by its ‘signature’[8] or else just does not identify it. If it’s not identified, you can’t say anything about what kind of molecule it is.

Ambassador Rycroft’s statement is therefore confusing: its uncertain reference to ‘sarin or sarin-like substance’ is incompatible with a claim that the chemical was Syria’s military grade sarin. Either Porton Down scientists showed the sample to be military grade Sarin, in which case Assad would be strongly implicated, or it failed to, in which case he would be in the clear.[9]

If UK/US authorities have definite evidence implicating Assad, they have no reason not to share it (and, one might have thought, quite a strong incentive to do so). As long as they fail to, the reasons for doubt will remain.



A special word of thanks goes to Paul McKeigue, Professor of Genetic Epidemiology and Statistical Genetics at the University of Edinburgh, for his advice on the science and its application to the question at hand.

[1] In the words of Ambassador Rycroft, Assad’s responsibility is ‘highly likely’. (This is the same form of words used by the Joint Intelligence Committee in its 2013 briefing to Prime Minister Cameron before the emergency debate on support for Obama’s proposed bombing of Syria. Then, as now, hearers of the words were asked to take on trust that there was more compelling – and yet still not definitive – evidence than they were being shown. Having the opportunity to debate the matter at length, the MPs voted against.)


[3] The most readable, now classic, source on the chemical evidence of 2013 is Seymour Hersh’s ‘The Red Line and the Rat Line’, London Review of Books, 17 April 2014 Seekers of further or more comprehensive information and analysis are referred to the extensive wiki resource of A Closer Look On Syria

[4] The bombing had looked so certain to go ahead that the UK parliament was recalled from recess to debate it.

[5] Obama’s surprise reversal of decision followed consultation with his ‘most senior military advisor’


[7] For how a lab in the Netherlands showed in 2012 that this type of analysis was feasible see Report of the Temporary Working Group on Sampling and Analysis to the Nineteenth Session of the OPCW Scientific Advisory Board.  Annex 2, Agenda Item 8 [Internet]. 2012 Sep. Available from:

[8] I am informed that this is a combination of retention time in the gas chromatography step and mass/charge ratio in the mass spectrometry step.

[9] Unless it turns out that there was some ‘misunderstanding’ about how the sample was gathered or the testing done. I mention this possibility because while soil samples can yield definite analysis of the chemical used, samples from blood or tissue (physiological samples) cannot. In 2013, the early use of soil samples (as furnished General Dempsey with the understanding referred to) was in subsequent cases ‘inexplicably’ supplanted by the less useful method of analyzing physiological samples by the US. (Perhaps some institutional learning about this was lost in the transition between presidential teams and perhaps Rycroft was not briefed on the significance of the point. But that, of course, is pure speculation.)

This entry was posted in disinformation, journalism, media, propaganda, Syria, UK Government, Uncategorized, war and tagged , . Bookmark the permalink.

20 Responses to Chemical Attacks in Syria: is Assad responsible?

  1. Elizabeth Ardley says:

    Excellent article. I presume you have read Professor Postol’s analysis of the White House intelligence report?

    Click to access Postol_assessment_041117.pdf

    And his Addendum:

    • timhayward says:

      Yes, and I recommend them to everyone! The premise of my post comes from the government’s position. I aim to show that even if one suspends disbelief and grants it, their claimed conclusion still needs to be properly demonstrated.

  2. Guy Crittenden says:

    How reliable is any sample delivered by Khan Shaykhun? For 25 years I edited a magazine called HazMat Management and, while we didn’t focus on chemical weapons (though we did cover cleanup of old military bases) we covered stories where testing of chemicals in soil and groundwater led to multi-million-dollar outcomes in terms of assigning blame for pollution. In addition to double-blind analytical testing from accredited labs, another crucial element was “chain of custody” i.e., proof that a given sample came from a given place. Idlib province is overrun with jihadist insurgent militias and many of the fighters who were shipped out of east Aleppo. These fighters have demonstrated the capability of fabricating sarin gas as has been indicated in dozens of attacks from them. It would be very easy for the militias to offer up samples suggestive of sarin gas use, after staging propaganda videos (which they’ve also been caught doing). I commend you for delving into the nitty-gritty of the samples themselves, but chain of custody is equally crucial here, if we’re going to get technical. Without a full-on independent inspection of the area and interviews with credible witnesses, I don’t think this can be resolved at all.

  3. A detection of military grade sarin would not solve the issue.
    1. Because 2 Syrian depots were located in rebel territory in 2013 and it is unclear what happened to their stocks.
    2. Because it is unlikely that rebels and their backers would repeat their 2013 ‘mistake’. If it was Turkey, that provided the sarin as alleged, they could easily provide military grade sarin this time. The same is possible for any other foreign intelligence agency, supporting Al Qaeda.

    • timhayward says:

      Thanks for the comment. Technically, yes. If the UK statement had confirmed military sarin then we’d have to deal with your questions. But since the UK didn’t confirm it, and expressly equivocated on the matter, I’ve set them aside for now as hypothetical. (As for info suppliers not repeating mistakes, I wouldn’t rely on it!)

  4. Guy Crittenden says:

    And now there’s this from Truthdig. This is devastating to the White House account.

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  6. Marko says:

    There’s no way a chemical signature , even if it’s a dead ringer for Assad’s stockpile , can definitively implicate Assad , or even weigh heavily against him. Any rebel group in Syria may well find it easy to obtain some of Assad’s old stock , easy , that is , if they have loads of cash they’re willing to part with. Or – and much more likely – they have deep-pocketed outside backers with said willingness.

    Remember , the country was literally overrun with 57 varieties of outside mercenaries when they were trying to locate and collect that stockpile for destruction. It only stands to reason that they didn’t recover 100% of that material. They may have said they did , but if so , they lied. They probably had to , knowing that otherwise the job would have continued forever. If they missed just 5% of a 1400 ton initial stock , that’s 70 tons that’s still out there , either stashed away securely , or floating around looking for top dollar. See this :

    From Foreign Policy (9-17-16 ) “How the Islamic State Seized a Chemical Weapons Stockpile “:

    “( Dec. 2012 )….Within a day, the combined jihadi forces had broken through the lines of the Syrian Army. Shortly after, Regiment 111 was fully under jihadi control. 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…..”

    That sort of thing has undoubtedly happened repeatedly. Syria – hell , the whole Middle East – is basically a big CW bazaar.

    Flip this story around , and consider that the SAA has no doubt come across some ” kitchen-grade” stockpiles that were abandoned by defeated rebels , which Assad could have then put aside for his own use , and you see that there are no conclusive “fingerprints” to be found , anywhere.

    • timhayward says:

      I take your points. My argument was just that if they had identified the sarin as associated with the Syrian state they would have had good reason to announce it. (To be implicated, as I understand the expression, is not to be conclusively proven against, but to have a strong prima facie case to answer – which, of course, could be answerable.)

  7. Brock says:

    Porton down is weaponised-the latest BBC doco on this place-talking scientists, told so many disproved stories wmds etc that I had to turn it off. The scientists there follow the party line. Why would the scientists tell the truth if it’s funded by the UK govt?

    • timhayward says:

      Thanks, Brock. I haven’t seen that. Is it a recent programme? Is it on Iplayer or Youtube? (A reason scientists might have higher thresholds for allowing deception to come in is that their account of results can either pass muster for other scientists – e.g. Russians – or not. I do not suggest scientific results are necessarily completely beyond manipulation; but I do think the quality required would be a bit more than people get away with in press releases or clips of White Helmets in action.)

  8. Anonymous says:

    There is zero custody trail for the evidence. The specimens were taken by possible perpetrators and passed on through unknown channels to agents of a regime with vested interests in framing Assad. The evidence would be laughed out of any court, which is why the Anglo-Zionists are absolutely emphatic there will not be an imaprtial investigation.

    Assuming there is ‘sarin or sarin-like’ ontamination on the samples, there are many possible sources. The OPCW stated that 10 out of 12 CW facilities in Syria have been decomissioned and weapons destroyed. The remaining two have not been examined because they are in terrorist-held territory. Another possibility – Israel operates a chemical and biological weapons reseearch facility at Nes Ziona. It conducts reserach into sarin, mustard gas and organophospahte chemical agents (amongst others). Israel supports terrorists in Syria providing them with weapons, air cover, medical facilities, etc. The Israel regime has said that it prefers Syria to be run by the terroriists rather than by Assad. It would be feasible for them to contaminate soil samples with trace amounts of ‘sarin or sarin-like substances’ them double-sealing the evidence in forensic sample bags. It would also be feasible for any other state with CW facilities to do the same.

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  10. ziad welds says:

    who is to say that certain amounts of sarin from syria’s ex stockpile has not found it’s way into the hands of these terrorists before it was all supposedly destroyed? I do not trust any of these players ,,also is it not possible for syrian army to have created a kitchen sample in order to lay blame on rebels? although the former is more likely and not so the latter as it would be too risky and no motive or logic for syria to do that but both are possibilities,,however it is more likely that the ” sarin like substance” was indeed rebel or foreign made ,,but im curious about the sarin supposedly sent by clinton from libya’s stockpile towards syria via turkey,,if that was used how would they ever justify the signature? obviously not being syrian made

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