Richard Lloyd's Trajectory Analysis

If this is your first time here, I recommend starting from the conclusion page.

Richard Lloyd of Tesla, who previously published a widely-reported estimate of 2 km for the UMLACA/Volcano's range, and confirmed the Syrian Army's report of a rebel CW store in Jobar, has recently published an analysis of the sarin rocket trajectories.

The analysis reaches very similar results to those published here and in other blogs, indicating a launch source to the north.

However, Richard points to an interesting finding: A Syrian Air Force Intelligence facility located on this trajectory, at a distance of 2.8 km from the farthest impact site. (Note: For some reason, the diagrams show the base to be exactly on the trajectory. However, the impact sites provide an accuracy of only around 20 degrees, which covers the entire field west of Irbin).

This is of course a very important finding, since so far there was no evidence of government activity near the launch site (despite numerous reports of such activities all over Damascus).

However, there are a few obstacles before this could be used as evidence:

1. The base is beyond the UMLACA/Volcano range. The report does not provide any explanation why a range beyond 2 km is considered (which was previously defined as the "upper possible range"). In any case, our more detailed model puts the upper limit at 2.5 km.
2. Air force Intelligence is an Internal Security and Counter-Intelligence service. It is not involved in military operations, rocket artillery or chemical warfare. More specifically, this facility seems to have civilian cars parked outside and no military equipment.

Nevertheless, some scenarios could benefit from this new finding: For example, if we are to assume that the government had specific interest in targeting the civilian neighborhood of Zamalka, it is definitely conceivable that they brought the launcher and support truck to the facility, drove them after midnight to the nearby field to launch the attack and then retreated back.

The problem with this scenario is that it doesn't provide any significant military advantage over the alternative of driving the trucks directly from the nearby highway into the field. It of course still doesn't explain the many other discrepancies with such a scenario.

During the writing of this post, Mr. Lloyd published another report, which makes two claims:

1. The wide distribution of impact sites could not have come from random dispersion around a single target, implying multiple launchers.
   The estimate of this blog is that a single launcher was used, each time rotated to a different azimuth. It is unclear why this simpler explanation is ignored.
2. The range of the chemical Volcano is longer due its smaller mass.
   This blog's model has already examined this and found the difference to be negligible, since the lower mass also results in lower resistance to drag force, which in this case has significant effect on range.

Conclusion: The Air Force Intelligence facility near the launch location could have provided some cover to a government operation, but since it is beyond the Volcano range, its contribution is negligible compared to the alternatives. Therefore, this finding, while interesting, does not have significant implication on culpability.

Ridiculed Jobar Lab actually was Sarin Related

If this is your first time here, I recommend starting from the conclusion page.

Richard Lloyd of Tesla, who previously published a widely-reported estimate of 2 km for the UMLACA/Volcano's range, has recently made another interesting discovery.

First, some background: Three days after the Ghouta attack, the Syrian news agency reported that Syrian soldiers who entered Jobar discovered an underground chemical weapons store, and that some of them suffered from "suffocation". This was quickly dismissed as a desperate attempt to divert attention, and the equipment was estimated to be related to explosives production or to protection from a chemical attack. This blog too did not find that report useful.

However, Mr. Lloyd managed to identify in a video of the location two items which perfectly match the sarin IEDs used against Syrian soldiers in Jobar, as reported in the final UN report. This attack was of special interest as it was the only one where the UN detected sarin in a soldier's blood sample (despite a one month delay in sampling).

See here the full report.

Update: An anonymous contributor below noted that the soldiers were attacked by the IEDs just 250m from the likely launch location of the August 21st attack. Besides further strengthening the connection between the two attacks, it provides another important indication: Since the Syrian army has reported being attacked while advancing into this area on August 24th, it is likely that the area (and rocket launch location) was under opposition control on August 21st.

Update: The UN reported that two cylinders seized in August by the Syrian Army tested positive for sarin. It is reasonable to assume this report relates to the IEDs found in Jobar.

Conclusion: The underground store discovered by the Syrian Army in Jobar was indeed a chemical weapons store.

Quote from Commission of Inquiry on Syria

If this is your first time here, I recommend starting from the conclusion page.

The Independent International Commission of Inquiry on the Syrian Arab Republic, has issued its 7th report which deals with many atrocities committed by all parties to the conflict, but also provided the following interesting quote (page 19):

The evidence available concerning the nature, quality and quantity of the agents used on 21 August indicated that the perpetrators likely had access to the chemical weapons stockpile of the Syrian military, as well as the expertise and equipment necessary to manipulate safely large amount of chemical agents.

The report also states that the chemical agents used in Ghouta were similar to the Khan Al-Assal attack, and concludes that "In no incident was the commission’s evidentiary threshold met with respect to the perpetrator".

This seems to indicate the commission had information that could prove valuable for our research here. Unfortunately, UN bodies have proven in the past to be a problematic source of information when dealing with the Ghouta attack, so some care should be practiced. Indeed, the first thing that stands out is that the commission does not provide any evidence to support its conclusion, or even provide an indication of what that evidence could be. This obviously renders this information unusable for our investigation.

Nevertheless, we can try to deduce what information the commission has by analyzing their statements.

A first clue is given in the first question in the press conference that followed the report, where the commission's chairman explains that since they did not visit Syria, their conclusion is based principally on the existing findings of Sellstrom's team, as well as "interviews with experts and functionaries".

A second clue is the comparison to the Khan Al-Assal attack, which is said to have "the same unique hallmarks as those used in Al-Ghouta". Since Sellstrom's team did not visit Khan Al-Assal and had no field samples, the only source for such a comparison would be Russia's 100-page report of the attack submitted to the UN, which included certified lab results of field samples. The full results were not published, but were reported to provide evidence that RDX was used as the bursting charge.

These clues bring us back to the well-known Hexamine issue - which serves as the current "smoking gun", ever since the "trajectory intersection" theory was refuted. Since RDX is based on Hexamine, it seems likely that the Russian labs reported Hexamine in their samples, which brought the commission to connect them to the Hexamine in the Ghouta attack (probably correctly), and both attacks to the Syrian stockpiles (probably incorrectly).

So since the commission refuses to provide any evidence, states that their conclusion is based on Sellstrom's data, and found similarities to Khan Al-Assal, there is little reason to believe they have more information besides the well-known Hexamine finding.

The other evidence mentioned is the amount of agent used, which is indeed one of the main challenges to the opposition-attack theory. However, detailed analysis indicates that while not an easy feat, producing such amounts is within the opposition's capabilities. The recent UN evidence showing the opposition deploying tens of kg of sarin, further strengthened this position.

As a side note, for those who are not familiar with the UN's multiple manipulations during the Ghouta investigation and choose to take this report at face value as indicative of a government attack, it should be pointed out that this would indicate that the only two cases where the government chose to use sarin at large scale are (a) an attack against Syrian soldiers in a government-controlled area, and (b) a massive attack on a purely civilian opposition neighborhood carried out upon arrival of a UN team invited to investigate the first attack. - An obviously perplexing choice of targets.


Finally, it is important once again to remember that the Ghouta attack is no longer a mystery where each little clue can change the picture (like it was in the early days). We now have very strong evidence implicating the opposition in the attack, and so far no one was able to propose a regime attack theory that is consistent with the evidence (see the end of this post to understand why this is so difficult). For our understanding to change, very strong contradicting evidence should be brought forward, or alternatively a plausible theory for a regime attack should be formulated. Vague statements or general-purpose chemicals claimed to be smoking guns, sadly, do not qualify.


Conclusion: The commission's quote seems to be based on the Hexamine findings and the amount of agent used, both of which have already been known and analyzed here before, and found to be of little value.

More on Hexamine

If this is your first time here, I recommend starting from the conclusion page.

In recent weeks new information has surfaced regarding the Hexamine findings,which require revisiting the issue.

First, to summarize the “Hexamine is the smoking gun” theory: This claim is based on Hexamine being reported by Syria as part of their chemical program, and Hexamine being found in all sarin-positive samples in Ghouta. Supposedly, this is a “smoking gun” connecting Syria’s stockpiles to the sarin used in Ghouta. The main objection raised so far to this theory is that Hexamine findings in the field could come from many sources, such as the rockets’ booster charge, and that Hexamine was never associated with sarin production – specifically, it is a well-known Mustard Gas stabilizer.

The new information:

1. Ake Sellstrom was quoted as saying that Hexamine “is in their formula, it is their acid scavenger”.
2. Dan Kaszeta has published on twitter a list of components found in US mustard gas containers, none of which contained Hexamine, decreasing the likelihood that Hexamine was used as a mustard gas stabilizer, and increasing the likelihood it was used for sarin.

Let’s examine these in detail.

Sellstrom’s Quote

There are three problems with this quote:

1. Quotes by Mr. Sellstrom should be taken with a grain of salt, given the many manipulations detected in his first report. He has specifically made a misleading statement in the past claiming that sarin found in the field was of higher quality than Iraq’s, while omitting the fact that Iraq produced very low purity nerve agents.
2. While the question did mention sarin, Sellstrom’s answer did not explicitly state Hexamine is used as an acid scavenger for sarin.
3. In the December press conference (13:00) Sellstrom presented himself as having little understanding of this issue.

US Mustard Gas list

These lists originate from a study done on Mustard containers kept at Aberdeen, Maryland, and indeed do not list Hexamine.

However, Aberdeen has been developing chemical weapons since 1917, while Hexamine was discovered to be a Mustard Gas stabilizer only in 1945. It is therefore possible these batches were manufactured before Hexamine was used, and indeed, the chemical agents are described in the reports as partly solidified.

Whether or not this is the case, it should be noted that this is of little relevance to Syria. Syria started its program in the 1990s, at which time the use of Hexamine was already published in several patents, one of them explicitly states: “Hexamine [is] currently adopted as the official stabilizer for Levinstein mustard by the [United States] Chemical Warfare Service” (as detailed here, the patents also state this applies to distilled mustard / HD).

So whether or not the US has used Hexamine for this purpose, Syrian scientists had easy access to this information, and it is definitely likely they would make use of it.

Hexamine is Probably not a Mustard Stabilizer

Despite these two findings not being enough to discredit the theory that Hexamine was used to stabilize Mustard Gas, there is another problem with this theory: Syria has reported very large amounts of Hexamine (80 Tons). Since Hexamine is used as a Mustard stabilizer at 1% concentration, this would equate to 8000 Tons of Mustard Gas, while it seems like Syria reported only 400 Tons. 

I therefore no longer believe Mustard stabilization is the main purpose of Syria’s Hexamine.

So why is it there?

First, let’s examine Dan Kaszeta‘s theory that it is an additive to binary sarin intended to neutralize HF generated during the final stage. As discussed in the past, Isopropylamine is the well-documented additive for this purpose. It was the choice made in all known sarin programs, and there is likely a good reason they chose a chemical that is closely related to one of sarin’s immediate precursors (isopropanol).

There is no reason to think Syria made a different choice, especially when we know they declared 40 Tons of Isopropylamine. Furthermore, this amount matches the report of 120 Tons of Isopropanol, which is close to the ratio required for mixing OPA (the 28%:72% mix of Isopropylamine and Isopropanol that is used in binary sarin). 

If we are to accept Dan’s claim that Hexamine is more efficient than Isopropylamine (“can bind to as many as four HF molecules”), then 80 Tons should equate to a much larger amount of sarin than was reported.

We can therefore safely discredit this theory.

Hexamine Still far from a Smoking Gun

At this point, it is hard to say what the exact purpose was. Hexamine is used in many organic chemistry processes, and there is no way to know whether it was used for neutralizing by-products, for assisting in synthesis of precursors, or directly added to the final products. There is also no way to know whether its use was related to sarin, VX, or mustard, all of which produce acids in the process (e.g. Phosphorous acid for Mustard Gas).

Whatever it may be, it is definitely not a “smoking gun”. It can maybe be qualified as “weak circumstantial evidence”. 

Before it is remotely useful in determining culpability, all the following points must be proven:

1. It was not intended for another purpose or for one of the other agents.
2. It was used in a way that keeps significant amounts of it in the final product (i.e. detectable in the field samples).
3. The Hexamine findings in the field originate from the sarin, and not from other sources such as the explosive booster charges. This is probably the weakest link in the chain, since the UN reported 3 Hexamine findings in sarin-negative areas, and several explosive-related findings in sarin-positive areas.
4. The opposition doesn’t also use it in their sarin process. Especially difficult to prove since the opposition is assisted by many Army defectors. If the government found Hexamine to be useful, this could have easily leaked.

Clearly, there is still significant work ahead for anyone trying to use Hexamine as evidence for regime culpability.

The Big Picture

Since it’s been a long time since we examined the scenarios, and it is easy to get lost in the details, this seems like a good opportunity to remember the big picture: Despite many requests, no one was yet able to provide a regime-attack scenario that is consistent with all the evidence. The main issues that make such a scenario highly implausible are:

1. Why was the attack carried out from a field near Irbin that is under opposition control, when the government possesses many long range chemical shells and rockets?
2. Why was the sarin manufactured using basic chemicals?
3. Why was a low-grade alcohol used in the process?
4. Why was a low-quality rocket, originally designed as an incendiary weapon chosen?
5. Why did they choose to attack a residential neighborhood behind the front lines for little military gain?
6. Why didn’t Western intelligence sensors detect activity at Syria’s chemical sites prior to the attack?
7. Why attack during the UN’s visit?
8. Why invite the UN and then divert them from the Khan Al-Assal investigation, especially as we now know Khan Al-Assal  to be a sarin attack against Syrian soldiers and pro-government civilians? It would seem the government had a strong incentive to allow the UN to carry out this investigation and publish these findings.
9. Is it pure coincidence that two more sarin attacks against Syrian soldiers occurred just a few days after the Ghouta attack, and in the same area?
10. What are the Liwa Al-Islam launch videos? If they are fabricated, why make them so unusable for mass media, and why publish them long after the military threat was averted? Is the Liwa Al-Islam sarin video published before the Ghouta attack also a fabrication? For what purpose? 

(More details can be found on the conclusion page).

Claiming that these severe discrepancies are somehow outweighed by a finding of some multi-purpose chemical in the field and in Syria’s stockpiles, is highly speculative.

It is especially problematic when we know there is a solid opposition-attack hypothesis that is fully consistent with all the evidence, and the only objections raised against it so far are extremely weak, namely:

1. We don’t have direct documentation of the opposition looting this specific version of the Volcano launcher.
   Weaknesses:
• We do have documentation of the opposition using the smaller Volcano version.
• The same claim is true for the government: There is no documentation of it using using this Volcano version (the incendiary/chemical).
• This claim assumes the Liwa Al-Islam videos, which show the opposition using the chemical Volcano are fabricated.
2. Despite ample evidence that the opposition is producing sarin, we don’t know the exact location of the opposition’s sarin production plant (sometimes ridiculed as “a giant secret plant”).
   Weaknesses:
• As described here there is no need for a giant lab using today’s laboratory technologies.
• The opposition is in control of vast areas of land. There is no reason to think we should be able to locate the plant.
• We do have documentation of the opposition capturing a large chemical plant.

Conclusion: While it is possible that Syria used Hexamine in the sarin production process, and it is not impossible that the Hexamine findings in the field are related to sarin, this is only one of many plausible explanations, and therefore very far from being a “smoking gun”. Given the much stronger evidence indicative of an opposition attack, and the lack of any plausible regime-attack scenario, this evidence is of negligible value.

Analysis of the Second UN Report

If this is your first time here, I recommend starting from the conclusion page.

This post analyzes the UN's final report on the use of Chemical Weapons in Syria, published on December 12th, 2013.

The report, which covers seven separate attacks, spans 82 pages and contains a mix of evidence collected by the UN, evidence reported by the Syrian government, UN analysis and estimates, and procedural documentation. This post attempts to extract from it new findings, which may be relevant for inferring culpability for the August 21^st attack.

Ghouta, August 21st

Given the multiple omissions and mistakes in the initial report of September 10^th, the final report was widely anticipated to provide more information and clarifications. Particularly interesting issues were (a) whether the wrong trajectories reported would be corrected, (b) any conclusions that could be made from the many chemical by-products found in the scene, and (c) clarifications on the numerous discrepancies in the Moadamiyah site.

In that aspect the final report was a huge disappointment. The writers simply chose to sidestep the issues by stating that the September report “forms an integral part of this final report” and only provided some minor updates to the lab results. This leaves us with two possible explanations:

1. The team had no new information to offer since the September report, despite the large amounts of raw data involved and its short time constraints.
2. The team simply wished to avoid highlighting the many mistakes made in the first report, by pretending the objective of the final report was only to investigate new sites.

Khan Al Assal, March 19th

The fact that a chemical attack occurred was already known, but the report adds two interesting findings:

1. Syrian soldiers were indeed attacked and the site was under Syrian government control at the time. These claims by the Syrian government were not widely accepted prior to the report.
2. The agent was an organophosporous compound. This matches the Russian’s finding of sarin in soil samples, but was also not widely accepted, especially since some eyewitnesses reported a Chlorine smell.

It should be noted that the team did not visit the site to take samples due to security restrictions, so their conclusions were based on numerous interviews, which they felt were strong enough evidence (or as mentioned in the press conference: “the footprints in the society… were so obvious”).

The report does not offer any reliable evidence on the delivery method.

Judging by a map attached to the report, the lethal area seems to be 2 hectares (200x100m), which matches the death toll of 25 people. Based on US DoD models, this translates to 20 kg of sarin used.

Bahariyah, August 22nd

In this event, Syrian Army soldiers were attacked by improvised devices distributing a blue gas with a very bad odour. The symptoms reported by the soldiers are clearly indicative of some irritant and not a nerve agent, and their blood samples were negative for sarin (samples were taken by the hospital on the day of the attack, and by the UN a month later).

Jobar, August 24th

In this event, Syrian Army soldiers were attacked by an IED. The interesting findings:

1. A sample taken by the UN team a month after the attack from one soldier tested positive for sarin exposure.
2. All 4 samples taken on the day of the attack by the hospital were positive. This includes samples from 3 soldiers who tested negative by the UN. This is likely explained by the long time passed.
3. The attack involved at least 4 IEDs of 4 liters each, which is 17.4 kg of sarin.

These findings are ground-breaking, as they show for the first time positive proof of a Syrian Army soldier being attacked by sarin. Combined with the evidence previously collected, it can now be ascertained with high certainty that the Syrian opposition possesses sarin.

Ashrafiya August 25th

In this event, Syrian Army soldiers were attacked by canisters launched by the opposition using catapults. One of them landed near a group of five soldiers and released a foul smelling smoke. They then experienced symptoms consistent with nerve-agent poisoning and were evacuated. The interesting findings:

1. All 5 samples taken by the hospital on the day of the attack were positive for sarin.
2. All 3 samples taken by the UN samples a month later were negative .
3. One sample taken by the UN 5 days after the attack was negative.

Since we have both a government and a UN positive result in Jobar, and a match in the negative results provided by the government in Bahariyah, it is safe to trust the positive samples in this case and attribute the negative samples to the time passed.

However, the last finding raises an obvious question: Why was only one sample taken from the five injured soldiers? The astounding answer is hinted in the report:

"Biomedical sampling was performed on 30 August 2013 on selected patients… Due to technical problems during the sampling, only one blood sample was recovered”. 

The following points may help better understand this statement:

1. The report goes to great lengths to describe the meticulous procedures used by the UN team to protect the integrity and authenticity of samples.
2. The team did not report any procedural failures in the collection of samples from makeshift hospitals in the warzone, but only in this secure military hospital.
3. The UN’s visit to the hospital was reported by the media, but for some reason was not mentioned in the September report - an omission which raised a few eyebrows at the time.

While previously there was some hope that the UN's multiple mistakes were somehow attributable to human error, this mess-up leaves us with the unavoidable distressing conclusion that someone within the UN team has been manipulating evidence. The blunt error in the Zamalka trajectory, the ridiculous analysis of the Moadamiyah “impact site”, and now the loss of blood samples cannot all be honest mistakes, especially when considering all three happen to contribute to the regime-attack theory.

This suspicion must be investigated to ensure this would never happen again. A first good step would be to pressure the UN to expose the full raw data (e.g. the raw GoPro recordings, and quantitative lab results).

Saraqeb 29 April

This case, along with a similar attack two weeks earlier, was extensively analyzed by Brown Moses here, here, and here.

According to the opposition sources quoted in the report a helicopter dropped an improvised weapon built from a cinder block with holes containing grenades whose safety pins were removed. When the block hits the ground and breaks, the levers detach and the grenades detonate. The sources claim the grenades contained tear gas and sarin.

Following the attack 13 victims were evacuated to Turkey, of which a 52 year old woman died, and the rest quickly recovered.

The new findings:

1. Body parts taken from the woman in an autopsy tested positive for sarin exposure.
2. A blood sample taken from the woman had low cholinesterase levels, which is consistent with nerve-agent poisoning, but also other conditions such as a heart attack.

To make this incident even more puzzling, here are a few more details to consider:

1. Turkish doctors previously reported blood samples from all 13 patients tested negative for sarin, while France reported finding sarin in samples from this incident.
2. According to this eyewitness report, other people were affected in the same location as the woman. However, the UN report states no one else exhibited severe symptoms.
3. The grenades allegedly used in the attack are probably tear-gas or smoke grenades.
4. The opposition has acknowledged using these grenades, stating they were seized from Syrian army depots.
5. This was the only case (besides Ghouta) where the government accused the opposition of carrying a false-flag chemical attack (here and here).

So what happened in Saraqeb? The main scenarios to consider are:

1. A government attack using an improvised device containing previously unheard-of sarin grenades. The amounts used were so low that it had lethal effects only when falling in close proximity to a 52 year-old woman, indicating the use of sarin had no military gain.
2. The woman’s body was contaminated with sarin (or IMPA) in the Turkish morgue in an attempt to deceive the UN.
3. The lab results were a false positive.
4. A false-flag by the opposition, as claimed by the government.

None of these scenarios seem very plausible, leaving this incident a complete mystery. If anyone can make sense of it, please share your ideas.

Summary of Evidence

For the sake of clarity, here is the full evidence trail described above that links the opposition to the sarin attacks:

1. In Jobar, a blood sample independently taken by the UN from a soldier tested positive for sarin.
2. In Bahariyah, the only of the four opposition attacks that was not a sarin attack, the samples supplied by the hospital were also negative, indicating the government was not attempting to tamper with evidence.
3. In Ashrafiya, the hospital provided 5 positive blood samples, which were confirmed to be from the attacked soldiers.
4. In Khan Al Assal the UN team was convinced from interviews with the victims and medical personnel that an attack with an ogranophosphorus compound has occurred against soldiers and civilians. This adds to the sarin findings by the Russian investigation team.

Conclusions:

1. The opposition attacked Syrian government soldiers and government-supporting civilians with sarin on three separate occasions.
2. The opposition has access to at least tens of kg of sarin. This significantly increases the plausibility of them being able to obtain the hundreds of kg needed for the Ghouta attack – closing one of the main gaps in our current scenario.
3. Elements within the UN team have likely manipulated evidence in attempt to incriminate the Syrian government.

Review of UN Press Conference

If this is your first time here, I recommend starting from the conclusion page.

Before examining the findings of the full UN report published recently, I thought it would be interesting to review the press conference that accompanied it, which provides some interesting information.

The most interesting findings:

16:00 - While probably not too relevant anymore, Sellstrom makes a very significant statement distancing himself from the "trajectory intersection" theory, saying "The flight paths do not seem to meet as may be indicated in the report", and adds that a range of 2km for the UMLACA is "a fair guess".

9:30 and 17:10 - In these two questions Sellstrom is asked about the sarin's quality, referencing his early statement that hinted at high-quality sarin (which was of course interpreted to imply regime culpability). He seems to avoid the first question (9:30) by addressing only the recent incidents where samples were taken from blood and not from soil. The second question (17:10) is more direct, prompting the interesting and evasive response: “I tried to make some comment on the quality of sarin and I compared it to my experience in Iraq”, which seems like an attempt to downplay the original statement and undo its effect.

41:00 - Probably the most interesting finding. Here the panel is asked whether the munitions reported by Syria to the OPCW were related to those used in Ghouta. The response:

"I could say 'No Comment', but I will give you an answer: Not really, there’s no information that sheds light on what happened in Ghouta”.

To understand the significance of this statement it should be explained that the information provided by Syria to the OPCW is confidential and cannot be shared. Sellstrom therefore cannot answer the question directly, but his response heavily hints that UMLACAs were not reported as a Syrian chemical weapon, which is in line with the analysis that it is a repurposed incendiary rocket. Of course, other explanations are also plausible, such as the government secretly destroying a stockpile of chemical UMLACAs to avoid it being associated with the attack.
Update: This report claims that UMLACAs were indeed not reported to the OPCW, but does not provide direct evidence.

Overall, it is hard to miss the difference in attitude during this press conference compared to the spirit of the interim report. While in September the message was along the lines of "We're not allowed to tell you , but we all know who did it", the team is now much more cautious, clearly stating that the evidence is insufficient to implicate either side (39:00), and there is no "information that will stand in court" (43:30).

Update: This WSJ article about the UN report contains two interesting statements from Sellstrom: 

But Mr. Sellstrom said he believed both sides in the conflict had the "opportunity" and the "capability" to carry out chemical weapons attacks. Mr. Sellstrom had just arrived in Damascus to negotiate a visit to Khan al-Assal when the Aug. 21 attack occurred. He said one of his earliest reactions to the attack was that the Syrian government had to be stupid to pull it off with U.N. inspectors in town.

Did I miss anything? Please share your evidence and analysis and help improve the conclusions.

Hexamine is not the Smoking Gun

If this is your first time here, I recommend starting from the conclusion page.

In his recent analysis, Dan Kaszeta provides some interesting chemical analysis of the recent UN report, and also suggests Hexamine could be the smoking gun of the Ghouta attack, going so far as describing it as "very damning evidence of government culpability".

The reasoning could be summarized as follows:

1. Hexamine was reported by the OPCW as part of the Syrian chemical program. This implies it had a purpose in the program, rather than being used for explosives manufacturing etc.
2. Hexamine can be used to bind the HF generated during the sarin binary process.
3. No one else is known to use Hexamine for this purpose.
4. Hexamine was found in multiple samples taken by the UN in Ghouta (both Zamalka and Moadamiyah).
5. It is unlikely the opposition will choose the same HF binding chemical as the government, implying government culpability.

I believe there is a much more plausible explanation for these findings:

1. As Dan notes, the standard chemical for binding HF in the sarin binary process is isopropylamine. It was used by the US for this purpose, it was declared by the OPCW (in the same report), and it was ordered by Al-Nusra in Turkey. There is no reason to believe Syria decided to replace it with Hexamine.
2. So why was it part of Syria's chemical program? This is easily explained when remembering Syria produced not only sarin, but also mustard gas. Hexamine is a well-known stabilizer for mustard gas, discovered in 1945 and adopted by the US Army's Chemical Warfare Service.
3. Which now requires us to explain the Hexamine findings in the field. These are not surprising given the many uses and high accessibility of Hexamine. Specifically of interest are its uses in explosives (which were used to disperse the sarin) and as heating tablets for camping stoves, which are probably widely used in these neighborhoods under siege.
   This conclusion is further strengthened when considering that (a) Hexamine was reported in several samples that did not contain any indications of sarin, and (b) some samples contained other explosive-related chemicals such as TNT and trinitro triazine.

Update

Dan Kaszeta has referred me to this US Army publication, which states on page II-38 that "a small amount of degradation occurs when stored in steel ton containers for over 50 years". It should be noted this refers to the pure form of mustard gas (HD), which is different than the Levinstein Mustard (H) mentioned in the patent above (70% purity). Dan claims H is an obsolete agent, and since "pure HD is quite stable on its own", Hexamine could not be a mustard gas stabilizer, as previously claimed.

This is an important correction which requires revisiting the analysis.

First, we should confirm that Syria indeed stores HD and not H. There is no direct evidence that this is the case, but given that Iraq's inferior program reached purity levels of 90-95%, it is fair to assume Syria does have HD.

Second, we need to confirm that HD does not require stabilizers. The above US Army publication seems to imply it doesn't, but this one states "The stability of Levinstein mustard which has been purified by various methods is also improved by the addition of 1 per cent hexamine" (p. 42), and this patent discusses methods of stabilizing HD, stating "mustard gas thus purified still corrodes steel containers and the corrosion rate is fairly rapid at temperatures in the range of 110F. to 150F". Additionally, when considering that "pure" HD is actually only 96% pure, it makes sense that while it should degrade slower it might still need some stabilization.

Trying to settle this discrepancy I looked into the sources of the first publication and found the most significant one to be this research, which I could not find in full. However, according to its summary it is based on samples taken from US stockpiles held for 50 years. Obviously, these stocks were intended for long-term storage, which according to the other sources contain stabilizers. 

So apparently, the low degradation findings refer to the actual final product (containing Hexamine), and not the hypothetical chemical. 

While investigating this issue, I also found this interesting quote (here): 

"Regardless of the exact reasons for the instability of Levinstein mustard, the problem is fully recognized and is extremely serious during time of war and national emergency when it becomes necessary to build up a very great strategic reserve of this chemical warfare agent in contemplation of the fact that chemical warfare may, at any time, be resorted to."

This brings up another option: That the Hexamine in Syria's stockpile was intended for emergency production of large amounts of H. Since HD's advantage over H is in storage and not in battlefield use, this is a very plausible scenario.

Finally, Dan's response still fails to explain why Hexamine was found in the sarin-negative samples.

As a more general claim: Hexamine seems to have multiple uses in chemical warfare and multiple reasons to be found in the field samples (see many more here). Correlating the two is impossible before meticulously striking off all the alternative causes.

Conclusion: The Hexamine findings in the impact sites are not indicative of Syrian government culpability as they are not reliably linked to the Hexamine from Syria's chemical stockpiles.

Did I miss anything? Please share your evidence and analysis and help improve the conclusions.