Responsibility for the 2013 chemical attack has been a hotly contested, politically divisive issue, with a wide consensus in the West that the Syrian government was to blame, while Syria and its allies claimed that it was a “false flag” opposition attack, intended to bring about US intervention.

Rootclaim’s 2017 analysis went against this Western consensus, calculating an 87% likelihood that the Syrian opposition carried out the attack. Following the discoveries discussed below, this has now been updated to 96%, one of our most certain conclusions.