After almost 6.75 years of O in the Whitehouse, Putin knows he can do whatever he wants for the remainder of O’s term. Russia has very real economic and demographic problems but they are not going to go quietly into the night. Putin also knows that neither Europe or the US are serious about stopping radical Islam, and that leaves him as the only adult in the room on that topic.
I don’t think he is looking for WWIII, but I doubt he will shy away from it if Europe & the US get in his way. The question then is whether Europe and the US will go to war to stop him.