and had a bad time under their rule

A fascist dictatorship being replaced with a communist one.

I'd like to hear more about this alternative history you got rolling around your skull where Finland became communist. I live in the reality where they joined nazis (as Stalin knew they would, which is why he had to move the border away from Leningrad), participated in starving a city to death and threw POWs into death camps, not the other way around. And then they turned around, seeing the writing on the wall, and avoided justice that way.

And now they're still nazis.