That's all Putin is doing in Syria. He's just preempting the tidal wave of jihadis that'll be coming his way once the current fracas is over.  He figures it's better to exterminate these US-backed maniacs in Syria now than face them in Chechnya, St Petersburg and Moscow sometime in the future.  Can you blame him? After all, if Washington's strategy works in Syria, then you can bet they'll try the same thing in Beirut, Tehran and Moscow.

So what choice does Putin have?

None. He has no choice.  His back is against the wall. He has to fight.  No one in Washington seems to get this. They think Putin can throw in the towel and call it "quits" at the first sign of getting bogged down. But he can't throw in the towel because Russia's facing an existential crisis.  If he loses, then Russia's going to wind up on the same scrap heap as Afghanistan, Iraq or Libya. You can bet on it. So the only thing he can do is win. Period. Victory isn't an option, it's a necessity.