Syria is a small country which might, God forbid, become the cradle of a big disaster called World War 3.
Those who think, how noble on the part of Europe to open its gates to syrian refugees - think again. It would have been more noble if Europe had done something real to restore the order in Syria, and thus prevent the flood of refugees which is bad for all parties: Europe feels 'invaded" by people of another religion and mentality, the syrian refugees , unrooted from their natural environment, are planted in places where they'll loose their identity and dignity, becoming second-hand citizens for life.
Putin is trying now to do something about restoring that order. It's a bit late, but better late than never, as they say. His chances to succeed , that's entirely another matter. He's not alone, the iranians are there too; their main concern is to consolidate Assad's regime, and so, bring some kind of stability to the region where they also do have interests of their own.
It might work , if the americans won't interfere. It is the americans who have started the whole thing with the "arab spring' concept, and the naive demand for democracy to replace the heads of Mubarak, Khaddafi, Assad - the result being total chaos followed by the appearance in the area of the new, barbaric player called Daesh.
My guess is that Obama ,won't leave office in 2016 without first bringing about an armed conflict with Russia , conflict which might eventually escalate into a world war. The clash has started with the sanctions imposed on Russia over Ukraine dispute, and is now going on with the russians' effort to save Assad which is not what the americans want. I can only hope my guess turns out to be wrong.
Anyway, as an israeli, I don't trust any of the above (russians, americans, certainly not iranians)). We'll just have to wait and see how things evolve.