@Svejk
//I know middle-eastern politics are very convoluted but I don't think we should be supporting any Islamists anywhere no matter how expedient it appears to us.//
For once, I agree with you.
With our 20:20 hindsight, we can see that the ones with most to gain from the sarin gas attack were the rebels (or ISIS, if one and the same).
Obama defined nerve gas/WMD as a 'red line' trigger for boots on the ground. He hasn't followed through on that rhetoric, perhaps on word from his advisors that this is precisely what the terrorists want.
In fact, they're so keen on reaching paradise (must be death in battle) that the cruellest thing we can do to them is to let them live long enough to die of old age.
Assad's hands are not 100% clean of the gas attack but it is a weapon of last resort and he wasn't exactly on the ropes, at the time.
9/11 conpiracists hark to 'false flag' attacks (9/11 conspiracies popular among radical Muslims too, apparenty) and the gas attack could have been an actual example of cynically using your own people as victims to justify a war you want to initiate.
Sidebar: awakwardnesses over Ukraine aside, are the Russians showing signs of helping the world out with this problem or are they buying crudely refined petrochemicals from them, or what?