Oh wait!
He's bluffing with separatist regions.
Oh wait!
He's bluffing with invading Ukraine.
Oh wait!
He's bluffing with actual war.
Oh wait!
... TL;DR: Putin thinks a nuclear war is winnable. https://www.vox.com/2015/6/29/8845913/russia-war
NB: do you really think Putin cares how you feel?