The Conclusion

On August 21^st the world woke up to horrifying images of a chemical attack against civilians in Syria. Over time the details emerged: Rockets with sarin filled warheads landed in rebel-held residential areas, killing hundreds and injuring thousands. However, one crucial detail remained unclear: Who carried out the attack? Each side naturally blamed the other, with western intelligence agencies providing evidence supporting the opposition, and Russian intelligence supporting the regime. Both sides issued biased reports with cherry-picked evidence, only adding to the confusion.

This blog was created to counter these disinformation campaigns, by providing an open online collaboration platform to investigate who is behind the attack. It turned out to be very successful with dozens of contributors meticulously documenting and analyzing thousands of pieces of evidence. Due to the sensitivity of the matter, high standards were enforced: Only reliable evidence verified by multiple sources may be used. No unverifiable statements from a single source, no generous interpretations of blurred images, and no cherry-picked circumstantial evidence.

This post summarizes this effort and provides the final conclusion. It should not be read as an opinion piece that tries to promote a certain point of view by choosing convenient evidence and making unsubstantiated claim. It is the result of a ground-up process that started by meticulous collection of all relevant evidence (regardless of what theory it supports), scrutinizing each item, and examining which scenarios can best match the evidence. At the end of the process only one scenario was found plausible. It is presented below in a hierarchical structure that allows the reader to independently verify every statement: Just follow the links and you will always reach hard evidence: a video, an eyewitness report, a mathematical model etc.

The only plausible scenario that fits the evidence is an attack by opposition forces. Following is a description of the main findings, with each one linked to the evidence that backs it.

Background Evidence

This section provides background information on the attack that is not directly related to culpability, but is necessary for understanding the rest of the evidence.

On the night between August 20^th and 21^st the regime launched a wide scale attack on the Ghouta area.

• Evidence that a regime attack was ongoing at that time:
• Regime attacks on this area are a regular occurrence 
• Report of a non-chemical heavy artillery attack
• Opposition social media accounts reported heavy fighting at 1:15 AM, more than an hour before the chemical attack was reported.
• The US reported seeing rocket launches from government territory at about 1:00 AM (60 minutes before the chemical attack).
• All evidence and more details here (item 3)

On the same night, rockets with large sarin warheads (hereinafter “UMLACA”) landed in Zamalka, an opposition dominant residential area, killing hundreds.

• Evidence that sarin poisoning occurred only in the Zamalka area:
• There are dozens of first-hand reports of sarin poisoning, and all of them are from the Zamalka area (see examples here, here, here)
• It should be noted that initially the attack was thought to encompass nearly all of the Ghouta area. This was later found to be a misunderstanding due to nearby hospitals helping patients from Zamalka. The only town that continued to claim a chemical attack was Moadamiyah. However, this report was found highly unreliable.
• See full analysis of the Moadamiyah site here
• Evidence that UMLACAs landed in Zamalka:
• Multiple videos of UMLACA in their impact sites were found in Zamalka, some of them reported only a few hours after the attack
• Three UMLACA impact sites are analyzed here
• Video of a fourth Zamalka impact site
• Video of a fifth Zamalka impact site
• Human Rights Watch received from local activists information of 12 UMLACA impact site, all in the Zamalka area. Report and map here.
• There were no reports of UMLACA impacts anywhere else.
• Evidence that the UMLACA was the sarin delivery device:
• They were found immediately after the sarin poisoning, and in the same area. No other munitions were reported.
• The impact sites and rocket remains show no signs of damage from explosives or incendiary.
• The impact sites have remains of a container capable of carrying around 60 kg sarin. The remains are stripe-shaped, indicating the container was designed to explode on impact, tear open, and release its content to the environment.
• The UN has reported finding sarin in soil samples taken near the impact sites.
• More details in the UN report.
• Evidence that hundreds were killed:
• We have not yet concluded our analysis of the number of casualties, but most sources report numbers in the hundreds. A good analysis of the different sources may be found here, reaching an estimate of less than 500.

Primary Evidence

This section contains findings which are directly indicative of a rebel attack.

The attack was launched from an opposition-controlled area 2 km north of Zamalka.

• Evidence the rockets were launched from the north:
• One impact site was documented by locals during the UN visit, showing a rocket buried in the ground pointing north
• A second impact site was documented by locals a few hours after the attack, showing an UMLACA and crater clearly pointing from north to south
• A third impact site was documented during the UN visit showing a hole in the northern wall of an apartment
• Full details here
• Evidence the rockets were launched from 2 km north:
• The UMLACA’s maximum range is 2.5 km, as indicated by:
• Computer simulations.
• Three videos showing launches of this rocket (although with a different warhead).
• A comparison to other rockets with known range
• Two expert opinions
• Full details here
• The 12 impact sites seem to form an arc around this launch site (see map below)
• There is an open field in that area, which would make an UMLACA attack (which requires two trucks) easier to coordinate
• Evidence the area is opposition-controlled:
• A map prepared by HRW shows it as "opposition contested area" (no separation between full and partial control).
• A map reportedly obtained from Syrian troops shows the area as "rebel held".
• The Wikipedia map shows the area as partly "rebels held" and partly "contested". It is very far from regime held territories (excluding the freeway).

The sarin was of low quality and contained impurities that indicate it was likely produced underground and not in a military plant

• The evidence:
• The UN reported finding multiple chemical impurities, indicating failures in the sarin production process.
• Two of the impurities are directly indicative of low-budget underground production.
• Eyewitness accounts are near unanimous in their reports of strong odors, whereas pure sarin is odorless.
• The UN report found no indication of chemical stabilizers in their samples, which are often used in military-produced nerve agents.
• Syria has an advanced chemical warfare program, which can be assumed to produce high quality agents.
• All evidence and more details here and here.

A video leaked by an anonymous source associates Liwa Al-Islam (a Jihadist rebel faction) with a rocket attack that is likely related to the chemical attack

• Evidence the video depicts a Liwa Al-Islam attack:
• The cameraman describes it as such.
• Liwa Al-Islam flags are seen on the launcher.
• Evidence the attack in the video is related to the chemical attack
• The time reported in the video is the night of the attack.
• The video contains several indications of its location, which could only be matched to the real location of the attack.
• The video shows three UMLACA launches.
• The fighters are wearing gas masks.
• The video is unlikely to be a fabrication, since it is very ineffective as propaganda, specifically:
• The video quality is very poor, making it unusable for mass media distribution.
• The specific launches documented in the video are on regime forces, and on different neighborhoods (not Zamalka).
• The videos show a Howitzer canon being used, which was never associated with the chemical attack before.
• The videos were leaked nearly 4 weeks after the attack, when the risk of military intervention already subsided.
• Full analysis of the videos here 

Map of the attack:

Red triangle - Likely source of the attack. 

Red pins - UMLACA impact sites in Zamalka (with calculated trajectories in greeen). 

Purple pins - Areas reported to have been attacked by UMLACA in the Liwa Al-Islam videos. 

Red line - Border between rebel-held area and contested area, according to Wikipedia's map.
Blue line - Border between contested and regime-held areas (i.e. Qabun and Jobar are contested)

Secondary Evidence

Despite the strong primary evidence, the rebel-attack scenario could not be accepted without answering the following questions:

How did the opposition obtain sarin?

Syrian opposition groups have been building chemical capabilities for some time, and most likely manufactured the sarin themselves.

• Evidence that the opposition acquired sarin:
• A Syrian opposition group was arrested in Turkey attempting to acquire chemicals that can only be used to manufacture sarin.
• Production of sarin in the quantities used to attack Zamalka is within the reach of well-funded underground organizations.
• More evidence here 
• Evidence that the opposition used chemical weapons in the past
• While there were many claims of chemical attacks, there was only one prior to August 21^st that had a significant number of casualties and was consistent with a nerve-agent attack. This attack in Khan Al Assal in April targeted Syrian troops and regime-supporting civilians.
• A UN investigator of war crimes in Syria shared her personal impression that prior chemical attacks were initiated solely by the opposition
• Additionally, the UN has found strong evidence indicating two sarin attacks on Syrian soldiers occurring a few days after the Ghouta attack (details here).
• Full details and more analysis of previous chemical attacks here

How did the opposition obtain UMLACAs?

While manufacturing sarin is a task within the capabilities of such groups, developing a rocket with an effective chemical warhead is fairly complex. Stealing one would also be very difficult, since Syria’s chemical weapons are heavily guarded. However, it turns out that the UMLACA was originally designed as an incendiary weapon, and not a chemical one. The opposition could have easily captured a stock of these incendiary UMLACAs and refilled them with sarin.

• Evidence that the UMLACA was a Syrian Army incendiary weapon, refilled with sarin:
• All previous reports of the UMLACA with this warhead showed clear signs of White Phosphorus or a similar incendiary surrounding the impact sites.
• These signs were not found in the impact sites of the sarin attack in Zamalka.
• Chemical and incendiary warheads have similar designs, and in some cases the same design is used for both.
• Full details here.
• Evidence that the opposition has access to nearly every weapon of the Syrian Army:
• Raids on Syrian Army depots are a frequent occurrence.
• There are numerous videos showing the opposition using looted weaponry, including tanks, APCs, artillery, rocket launchers, and even surface-to-air missiles. 
• More details here.
• An opposition raid on a site that was likely to hold incendiary UMLACAs is documented here.

Refuted Contradicting Evidence

While the evidence for a rebel-attack is very strong, we must also verify there is no strong evidence to support the competing regime-attack theory. This section lists evidence which was used in the past to imply regime culpability.

Western intelligence agencies claimed the attack spanned a large area and was therefore beyond the capabilities of the opposition.

• As described above, this was a result of initial confusion. All first-hand accounts and UMLACA sites are in the Zamalka area. The attack was launched from a single location by a small team, and does not require the large-scale coordination claimed.

Human Rights Watch found that two rocket trajectories reported by the UN (one in Moadamiyha, one in Zamalka) intersect at a large Syrian Army base.

• First Trajectory (Moadamiyah): 
• The evidence indicates there was no chemical attack in Moadamiyah.
• According to the details given by the UN, the Moadamiyah trajectory is unreliable.
• Second trajectory (Zamalka):
• The azimuth was miscalculated by 60 degrees. It points north, not west.
• Two other impact sites in Zamalka also indicated a northern source.
• The distance from Zamalka to the suspected Syrian army base is 9.5 km, while the UMLACA’s range is 2.5 km.
• See the map above for the correct source of the attack.
• Full details here

The UN reported chemical stabilizers were found in the soil samples, indicating a military source.

• This was a result of a reporter misreading a statement in the UN report. No stabilizers were found. Full details in update 2 here.

The US reported rocket launches from regime-held territory 90 minutes before poisoning reports flooded social media (i.e. 1:00 AM).

• These were part of a regime conventional attack. Eyewitnesses consistently report the chemical attack started at 2:00 AM.
• Full details here (item 3).

US and German intelligence claimed to intercept calls confirming regime culpability.

• These was shown to be highly unreliable here (item 4) and here.

A former Syrian officer claims that he was in charge of chemical warfare, and was ordered to use chemical weapons.

• His story was found to be unreliable, and probably an attempt to provoke international intervention. The evidence:
• Photos of him found online indicate he was not in military service during the war.
• His discussion of chemical weapons shows poor understanding.
• Full analysis here.

The US and UK intelligence claimed Syria has used chemical weapons on a smaller scale on 14 occasions.

• These were analyzed one by one, concluding that the regime has used White Phosphorus and possibly less-than-lethal chemical agents against opposition fighters, but there are no reliable indications of nerve agent use by the regime.
• A similar analysis by the Harvard Sussex program on chemical and biological weapons reached a similar conclusion.
• Full analysis here.

Refuted Supporting Evidence

This section lists evidence that was claimed to support the rebel-attack theory, but was found to be unreliable. Although not relevant to evaluating this scenario, it is provided here to demonstrate the neutrality of the evidence analysis process.

Local activists admitted that the poisoning was a result of an accident involving chemicals brought from Saudi Arabia.

• A close reading of the text indicates the locals are most likely referring to another accident and the reporter heavily edited their quotes to make it seem related.

Hostages have overheard a Skype call in which rebel commanders admit the attack was a rebel provocation.

• Like the calls reported by the US and Germany, these were most likely speculations misinterpreted as actual knowledge.

Full details and more cases here.

Motives

To reliably determine culpability, evidence should be accompanied by a motive. Two possible motives were found plausible:

Targeting Mistake

The Liwa Al-Islam videos indicate that the sarin UMLACAs were intended to be used against regime forces, and the launches are probably in response to the regime attack that started earlier. The attack on Zamalka may therefore have been the result of a targeting mistake – either in azimuth calculation, or in wrongly identifying Zamalka as regime territory.

False flag

Another plausible explanation is a deliberate attack on an opposition neighborhood, in attempt to meet the US’s red line for intervention. This could possibly be an unauthorized decision made by the chemical rocket team.

Detailed discussion of scenarios and motives here. 

Regime Attack Alternative

Besides demonstrating the high likelihood of a rebel attack, the research also exposed the implausibility of the regime attack scenario: To believe that the attack was carried out by the regime, one would need to assume the following:

1. The regime decided to carry out a large-scale sarin attack against a civilian population, despite (a) making steady gains against rebel positions, (b) receiving a direct threat from the US that the use of chemical weapons would trigger intervention, (c) having constantly assured their Russian allies that they will not use such weapons, (d) prior to the attack, only using non-lethal chemicals and only against military targets.
2. The regime pressed for a UN investigation of a prior chemical attack on Syrian troops, and then decided to launch the large-scale sarin attack at the time of the team's arrival, and at a nearby location.
3. To execute the attack they decided to (a) send forces into rebel-held area, where they are exposed to sniper fire from multiple directions, (b) use locally manufactured short-range rockets, instead of any of the long-range high quality chemical weapons in their arsenal, and (c) use low quality sarin.

Detailed discussion and other regime-attack scenarios here. 

Summary

An analysis of all evidence relating to the August 21st chemical attack indicate it was carried out by opposition forces. According to the most likely scenario, they used looted incendiary rockets, refilled them with sarin they manufactured themselves, and launched them from a rebel-held territory 2 km north of Zamalka.

The evidence was presented above in a unique structure that allows the reader to independently verify every claim. The purpose of this structure was to make sure that you, the reader, can reach one of three mindsets:

1. Contradicting evidence – You followed the links and found faulty evidence, or you have reliable contradictory evidence that was not yet considered. If so, please post your findings in the page where that evidence is discussed. We will then scrutinize it and if it holds up, the conclusions may change. Thank you for contributing!
2. Alternative theory – You agree with the evidence but can come up with an alternative theory that better explains it. So far no one was able to come up with a plausible regime attack scenario, but maybe you can. Post your suggested scenario here and we’ll discuss it. Thank you for contributing!
3. Convinced – Awesome, glad we could be of help. All we ask is that you spread the word and help us change the mainstream perceptions. Let’s prove that an open collaborative effort can overcome governments’ propaganda and disinformation. This is not just an intellectual experiment. Every day that passes with the world thinking the regime is behind the attack, is another day where the real perpetrators are accumulating sarin and improving their capabilities. It is just a matter of time until it is used outside Syria.

Many thanks to all the contributors. Amazing work!

Members of the media wishing to publish the report, please email sasa1wawa@gmail.com.