Background
This analysis is based on an older version of our inference model which is accurate but more difficult to read

Question

Did opposition forces have access to sarin?

23 Nov, 2016

Who carried out the chemical attack in Ghouta on August 21, 2013?

Scenariosinfo icon

Calculated Conclusionsinfo icon

Conclusionsinfo icon

1

99.6%
Had sarin:
Opposition forces had sarin
99.6%

2

0.4%
No sarin:
Opposition forces did not have sarin
0.4%
Implied plausibility
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Likelihoods based only on other elements of the analysis, not considering evidence of this sub-topic.
Had sarin
36%
No sarin
64%
Compatibility with evidence
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Likelihoods based only on evidence of this sub-topic, assuming all hypotheses equally plausible.
Had sarin
99.6%
No sarin
0.4%
Conclusion
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Final likelihoods, combining plausibility and evidence.
Had sarin
99.6%
No sarin
0.4%

Analysis

Evidence (4 items)

Russia and Syria reported that biomedical samples from the victims of attacks on August 24-25 in Jobar and Ashrafiyah Sahnaya tested positive for sarin exposure. One sample taken by the UN from the Jobar attack a month later tested positive, while from the Ashrafiyah attack, a UN sample taken 5 days after the attack and 3 samples taken a month later all tested negative.

Had sarin
96.2%
No sarin
3.8%
Had sarin
96.2%
No sarin
3.8%

In July 2013, a Syrian national connected to Jabhat al-Nusra in Syria, and four Turkish citizens, were accused of attempting to acquire chemicals (in Turkey) in order to produce sarin.

Sources: Al-Monitor
Had sarin
76%
No sarin
24%
Had sarin
76%
No sarin
24%

A video uploaded to Liveleak.com in April 2014 purports to show the aftermath of a chemical attack by Jabhat al-Nusra fighters.

Had sarin
82%
No sarin
18%
Had sarin
82%
No sarin
18%

A video uploaded to Youtube in July 2013 by a pro-Assad channel includes a purported recording of members of an opposition group (

Liwa al-Islam
) referencing sarin gas.

Alleged reference to Sarin gas by Liwa al-Islam fighters
Had sarin
55%
No sarin
45%
Had sarin
55%
No sarin
45%

Discussioninfo icon

This topic is part of a broader analysis. To view the discussion page of the main analysis, click below:
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