Eclectic
I said proof, not propaganda videos. You know, something like an unequivocal statement from the UN that the regime has used CW, or even a definitive statement from one of the politicians itching to get involved. Wee Willie's "belief" doesn't count, after all some people believe in Santa and the Easter
Bunny.
And of course those nice, friendly, rule & fairness-adhering chaps in Al Qaeda PLC. wouldn't dream of using Bio-Chemical weapons on an area of secularist Syrian civilians would they?
As a good percentage of the "rebels" are not Syrian they wouldn't actually be using CW on their "own" people, would they?