>>508876042 (OP)>How realistic is it at this point?0% chance.
Only potential areas of interest are the Suwalki gap (where Poland and Lithuania try to walk back signed treaties ensuring Russian passage to and from Kaliningrad.
And ofc the Baltics where the Russian minority are facing extreme discrimination and lack of human rights.
As for fighting in the rest of Europe?
Russia, nor the USSR never considered a non nuclear war for the rest.
So that's the only type of war there would be, a bombing campaign from a distance that ends in negotiations or nukes (like the Ukrainian regime in exile orchestrating massive terror campaigns from Europe).
Following brief negotiations between Russia and the US where Russia essentially says "we know you are pulling the strings, but we will limit out punishment to your puppets" and the US reluctantly promises not to send nukes back.
Russia doesn't need the land, and they don't need the people.
Apart from what would be classified as their diaspora.
That is why you signed up to spend 5% of GDP (10% of the budget roughly) on military stuff that is useless in a nuclear war.