Who made the decision to use chemical weapons on the one year anniversary of the US government’s red line declaration? Consider how ruthless and clever that decision was, to challenge US credibility on a day that would guarantee media focus on the slaughter and American response. Consider the nature of the challenge: if the US did nothing, its credibility would be even lower than it was post-Egypt; if the US lobbed a few cruise missiles at various sites, its credibility would also be zero. These outcomes would be to the advantage of several parties. Consider further that ambiguity was injected as to who was responsible for chemical attacks. Conspicuously, it was only a month ago that Russia delivered a report to the UN claiming that rebels had used sarin in March. Someone wants to be the strong horse; someone knows a fool when he sees one. We’re not alone in seeing Putin as possibly behind this.
(Of course it could always be Iran which was the prime mover, instead of Russia. They have important strategic reasons of their own to make the US look weak and foolish.)