So while I think Gabe is right that some sort of grand bargain in which Russia exchanges support for Syria for guarantees about American behavior in the post-Soviet space would be win-win, it will simply never happen unless the domestic political situation in the US changes beyond all recognition.
It was an honest attempt to resolve the un-resolvable, but as Adam Ozimek of Modeled Behavior points out in this awesome post, we overlooked one crucial element: PURE RAW MUSCLE POWER!