I’ve always thought this was the reason that Ambassador Stevens was killed via Whitehouse inaction. Given Stevens’ lifestyle and personality, I figure he was talking too much, too soon and needed to be silenced.
Either that or it was pay back for numerous attempts on Assad’s life. The Russians knew that ISIL was the real bad guys all along. Now ISIL has taken a lot of the military hardware they took from Iraq, and have driven it back into Syria. So yes, fairly soon Syria will become even more unstable then it is, and that will bring in Russians by the thousands.