Putin could definitely go ahead and push some buttons if he so chooses....and shortly thereafter he and Russia would get their asses vaporized as well!

He may be crazy and a bully, but he's not stupid for himself and his loved ones. Believe that! (in order words, at the end of the day he ain't making THAT move because he knows if he does Mother Russia and everything he loves will be a memory). And IMO he loves himself way too much for that!