I think that, with his Syrian adventure, Putin has stayed true to his foreign policy grand strategy of reasserting Russia’s position on the world stage. It’s also made Ukraine and Crimea yesterday’s news in foreign policy terms. The Western sanctions that followed that episode hurt Russia with falling oil prices and the rouble halving in value. Putin probably hoped that his Syrian foray, which was, of course, contrary to the interests of the Western powers, would deflect their diplomatic attention and perhaps even give him some leverage with them. Who knows, as suggested earlier in the thread, maybe some deal has been made to reward Russia for its military withdrawal.
I think Putin’s primary objective within Syria was to shore up the Syrian government’s position, ensuring that it wouldn’t fall, and to therefore, at minimum, enforce a military stalemate. Having now achieved this aim, he might have felt that there were rapidly diminishing returns in committing further Russian military support to the goal of pushing back the rebels, out of the areas in which they have become heavily entrenched.
Assad’s position is now safe and I don’t think there’s any chance he will step aside as part of a power-sharing agreement or as part of any peace process. I think Russia’s objective now is for a peace settlement that will create a decentralised, federalist Syria with the different regions governing themselves, but with Assad remaining as the figurehead ruling at the top. Russia has already made overtures to the Kurds and even secured a military airport within their area of control in the North of Syria.
It’s difficult, with the current situation on the ground and without some added external impetus, to see an alternative to the Russian plan that isn’t a continued and prolonged stalemate, descending into regional fiefdoms and warlordism, like Afghanistan or Somalia. Since Russia is maintaining some military presence in the country, the Syrian Army may continue to make progress against the rebels, albeit at a slower, reduced rate, and therefore be able to continue to put pressure on them to come to the negotiating table on Assad’s terms.
If Russia succeeds with this peace-plan, Putin will see himself as the one who was able to cut the Gordian Knot, succeeding where the West and others have failed. He’ll view this as a source of prestige for both himself and his country, and another successful piece of one-upmanship over Obama and his other political adversaries on the world stage.