My money is on Putin knowing that his war is not winnable, but not being able to save face internally by admitting as such. If he can poke the bear enough with incursions into NATO countries like the last few days though, he might be able to draw NATO into direct conflict, at which point a withdrawal/surrender can be sold as “We were attacked by the big bad NATO and had to consolidate our local defenses” rather than a defeat by what should have been an inferior force.