My thought as well. This thing has sprinted along at breakneck speed.-
This is probably less about Syria than it is about Iran, China, and N. Korea.
That may be. "A new sheriff's in town" message, perhaps?
I think some of this has to do with the US, through Tillerson, basically telling Assad we'd basically let him be, and then Assad (allegedly) throws it right back in our face.
The rather muted Russian attempts to forestall US action suggest that the Syrian AF DID gas their own people... If so, the Syrian gov't are damn fools. Trump is NOT Obama.