By Theodore A. Postol, professor emeritus of science, technology, and national security policy at MIT. Postol’s main expertise is in ballistic missiles. He has a substantial background in air dispersal, including how toxic plumes move in the air. Postol has taught courses on weapons of mass destruction – including chemical and biological threats – at MIT. Before joining MIT, Postol worked as an analyst at the Office of Technology Assessment, as a science and policy adviser to the chief of naval operations, and as a researcher at Argonne National Laboratory. He also helped build a program at Stanford University to train mid-career scientists to study weapons technology in relation to defense and arms control policy. Postol is a highly-decorated scientist, receiving the Leo Szilard Prize from the American Physical Society, the Hilliard Roderick Prize from the American Association for the Advancement of Science, and the Richard L. Garwin Award from the Federation of American Scientists.
For background on Dr. Postol’s previous essays on this issue, see:
- Exclusive: Top Missile and Chemical Weapons Expert Debunks Trump’s Claims About Syrian Chemical Weapons
THE NERVE AGENT ATTACK THAT DID NOT OCCUR:ANALYSIS OF THE TIMES AND LOCATIONS OF CRITICAL EVENTS IN THE ALLEGED NERVE AGENT ATTACK AT 7 AM ON APRIL 4, 2017 IN KHAN SHEIKHOUN, SYRIA
This analysis contains a detailed description of the times and locations of critical events in the alleged nerve agent attack of April 4, 2017 in Khan Shaykhun, Syria – assuming that the White House Intelligence Report (WHR) issued on April 11, 2017 correctly identified the alleged sarin release site.
Analysis using weather data from the time of the attack shows that a small hamlet about 300 m to the east southeast of the crater could be the only location affected by the alleged nerve agent release. The hamlet is separated from the alleged release site (a crater) by an open field. The winds at the time of the release would have initially taken the sarin across the open field. Beyond the hamlet there is a substantial amount of open space and the sarin cloud would have had to travel long additional distance for it to have dissipated before reaching any other population center.
Video taken on April 4 shows that the location where the victims were supposedly being treated from sarin exposure is incompatible with the only open space in the hamlet that could have been used for mass treatment of victims. This indicates that the video scenes where mass casualties (dead and dying) were laid on the ground randomly was not at the hamlet. If the location where the bodies were on the ground was instead a site where the injured and dead were taken for processing, then it is hard to understand why bodies were left randomly strewn on the ground and in mud as shown in the videos.
The conclusion of this summary of data is obvious – the nerve agent attack described in the WHR did not occur as claimed. There may well have been mass casualties from some kind of poisoning event, but that event was not the one described by the WHR.
The findings of this analysis can serve two important purposes:
- It shows exactly what needs to be determined in an international investigation of this alleged atrocity. In particular, if an international investigation can determine where casualties from the nerve agent attack lived, it will further confirm that the findings reported by the WHR are not compatible with the data it cites as evidence for its conclusions.
- It also establishes that the WHR did not utilize simple and widely agreed upon intelligence analysis procedures to determine its conclusions.
This raises troubling questions about how the US political and military leadership determined that the Syrian government was responsible for the alleged attack. It is particularly of concern that the WHR presented itself as a report with “high confidence” findings and that numerous high-level officials in the US government have confirmed their belief that the report was correct and to a standard of high confidence.
Methodology Used in This Analysis
The construction of the time of day at which particular video frames were generated is determined by simply using the planetary geometry of the sun angle during the day on April 4. The illustration below of the sun-angle geometry shows the Day/Night Sun Terminator at the location of Khan Sheikhoun on April 4. The angle of the sun relative to local horizontal is summarized in the table that follows the image of the planetary geometry along with the temperature during the day between 6:30 AM and 6 PM.
The next set of two side-by-side images shows the shadows at a location where a large number of poison victims are being treated in what appears to be the aftermath of a poisoning event. The shadows indicate that this event occurred at about 7:30 AM. This is consistent with the possibility of a nerve agent attack at 7 AM on the morning of April 4 and it is also consistent with the allegation in the WHR that an attack occurred at 6:55 AM on that day.
The timing sequence of the attack is important for determining the consistency of the timelines with the allegations of a sarin release at the crater identified in the WHR.
Assuming there was an enough sarin released from the crater identified by the WHR to cause mass casualties at significant downwind distances, the sarin would have drifted downwind at a speed of 1 to 2 m/s and for several minutes before encountering the only location where mass casualties could have occurred from this particular release. The location where these mass casualties would have had to occur will be identified and described in the next section. If there was a sarin release elsewhere, mass casualties would have not occurred at this location but would have occurred somewhere else in the city.
Assuming the victims of the attack were exposed to the plume, the symptoms of sarin poisoning would have express themselves almost immediately. As such, the scene at 7:30 AM on April 4 is absolutely consistent with the possibility of a mass poisoning downwind of the sarin-release crater.
The next figure shows the earliest photograph we have been able to find of an individual standing by the sarin-release crater where the alleged release occurred. The photo was posted on April 4 and the shadow indicates the time of day was around 10:50 AM. Thus the individual was standing by the crater roughly 4 hours after the dispersal event.
If the dispersal event was from this crater, the area where this unprotected individual is standing would be toxic and this individual would be subjected to the severe and possibly fatal effects of sarin poisoning. As a result, this throws substantial suspicion on the possibility that the crater identified by WHR would be the source of the sarin release.
At the time of the sarin release, the temperature of the air was about 60°F and the sun was at an angle of only 8° relative to local horizontal. This means that liquid sarin left on the ground from the dispersal event would remain mostly unevaporated. By 11 AM, the temperature of the air had risen to 75° and the angle of the sun relative to horizontal was at 66°. Thus, one would expect that the combination of the rise in air temperature and the sun on the crater would lead to significant evaporation of liquid sarin left behind from the initial dispersal event. The air temperature and sun angle are such that the area around the crater should have been quite dangerous for anybody without protection to operate.
This is therefore an important indication that the crater was probably not a dispersal site of the sarin.
The final set of three photographs shows arriving victims seeking treatment at a hospital at some location in Khan Sheikhoun. The arrivals at the hospital are at between 9 and 10:30 AM on the day of the attack. This is perhaps late since victims were seriously exposed by 7:30 AM, but victims could have been trailing in after the initial arrival of severely affected victims. This time is considerably earlier than the time at which WHR alleges that a hospital was attacked while treating victims of the poisoning attack.