Any solution to the Syrian conflict that comes before sarin is deployed will be tricky, and the pressure to deploy sarin has been anted up as rebels continue to advance on Damascus.
Already, Russia has warned Turkey about meddling in the internal politics of Syria, a major arms purchaser from Russia. Those differences have been papered over in recent days, but the use of sarin gas would cast a whole new light on the tenuous agreement.
Russia has tried to place itself as a neutral observer, leaning towards Assad -- the "status quo" would probably be the code they'd use to indicate this predilection -- but it has blocked no less than three UN resolutions asking Assad to step down peacefully or to provide UN support to the rebels.
But Turkey has deployed Patriot missiles to its border with Syria, and ostensibly these could be used at US direction to shoot down planes suspected of carrying chemical weapons. Too, Turkey has a dog in the hunt, since winds do not respect borders.
An ad hoc, presumably emergency meeting between Secretary of State Hillary Clinton and her Russian counterpart, Sergey Lavrov, has been arranged for this afternoon on the crisis. Perhaps Russia is reconsidering her position in support of Assad. Certainly, the chemical weapons -- which must be deployed by February 1 or thereabouts, else they'll lose potency -- raises the stakes for them.