As I mentioned when Russian airstrikes in Syria began, the airstrikes have nothing to do with Assad and everything to do with keeping Washington distracted, maintaining the status quo in Syria (that is, prolonging the conflict), and pressuring Turkey (as an expansion on the already decades-old play of keeping Armenia at odds with Turkey and Azerbaijan).
The Russians did what militaries so often do when they want to present a pressuring posture and forced the issue by violating a political target’s airspace while in the course of some other operation (consider the US Navy’s recently deliberate disregard of what the Chinese claim are their “territorial waters” in the South China Sea — though the issue there is almost exactly reversed: the Chinese are the aggressors in the sense that they are laying claim to broad swathes of ocean over which Beijing has never had any practical control). Turkey decided to take the opportunity to send a message to both Moscow and Washington by shooting down a Russian jet.
The important message Ankara is sending is that they will not cooperate on any terms with Moscow, that Ankara still considers itself a Western-ally, and — perhaps most interestingly — forcing the public dialog to become, at least temporarily, about the geopolitical game that is going on instead of the incidental and petty distraction of Assad and ISIS that has been filling the news. ISIS has used terror tactics to get in the news lately (Paris made a big splash, after all), and now Turkey has used a similar technique, though not terrorism by any stretch, to change the focus of public reporting for at least a few days.
If Washington was waiting for a green light in the region before surprising everyone with a sudden shift from Arab to Persian support, this was it. The best move right now would be for Obama to show up in Tehran tomorrow, and Washington to flip sides overnight, both with regard to Tehran/Riyadh and ISIS/Assad. By getting on the Persian side of things Russia has nowhere to go, loses its lever in Iran, and has to (for the first time in two decades) react to Washington instead of being the initiator. The Israelis and Egyptians will play ball — they have before and they will again (and judging by Bibi’s deft use of hyperbolic rhetoric over the last few years, he’s ready to make a deal that let’s Tel Aviv relax), and Turkey is all but shouting out loud in plain language that its time to pinch the destabilizing issues at their source.
Whether anyone who is allowed to make a decision is paying attention is anyone’s guess — the last several years of American policy make me wonder if anyone is paying any attention at all… which is probably why Ankara is trying its hardest to force a focus on the strategic issues that underlie the future-changing alignment shifts in the region instead of letting the public dialog remain purely about peripheral issues like ISIS and Assad.