The war in Ukraine is three days old.
Any domestic consequences for Putin in Russia will take time, months, even years to develop. They’re entirely possible, but don’t hold your breath yet.
And while it’s fun to speculate, we really have no idea of Putin’s mental state. At his age, is he really still the ice-cold calculating cold warrior who runs circles around his elected opponents who are just politicians, and he has a cunning plan to restore the USSR, just without communism?
Or is he just an aging dictator who is looking to close that big gap of freedom and democracy on Russia’s western border represented by Ukraine, so he is safely surrounded by authoritarian regimes he can control?
The Russians aren’t going to lose this war, and any crisis so dramatic the Russians would use nukes is hard to fathom. But this won’t be easy, it’ll be messy; above all it won’t be fast, and it won’t be over for the Russians any time soon. However the military situation plays out, probably messy and inconclusive too, the idea of just installing Medvedchuk or another pro-Putin Ukrainian leader and then pulling out is certainly a pipe dream.
Poland and the Baltics may be safe for now just because Russia is busy elsewhere. Ukraine won‘t be the same as Hitler rolling over Czechoslovakia, just an appetizer.