If Europe gives in to Russia in Ukraine, anyone with basic understanding of history can see that they'll turn their attention towards Baltics, Moldova and maybe Finland and Poland. Putin doesn't want to return those "good years" between cold war and Ukraine conflict, he wants to return to the glory days of Cold War when Russia (Soviet Union) was a real superpower.
Over here in Finland, we would absolutely love to have peaceful relations with Russia, based on mutual respect and trade. But we're under no illusion about it being possible with current Russian administration.