But Polish people were forced to lie about russia's involvement after WWII..
The only one lying is you.
No, we were not forced to lie about anything. I got my first communion in 1950 in Radom and later the confirmation in Warsaw - both without any resistance from the scary communists and their Soviet "minders".
I spent 20 years in "communist" Poland form 1945 till I left in 1966. Nobody forced me to do anything, lying included. Nobody tried to brainwash us about anything.
The worst: we were asked once to demonstrate in front of the US Embassy during Vietnam war. I didn't go. No consequences. I never participated in May 1 parades, either, and still managed to leave the country in 1966.
There was no "Soviet invasion" of Poland. The Red Army liberated Poland from Germans and left in 199x. Poland just happened to be on the way to Berlin. Duh, stupid.
BTW, the US Army liberated Germany and never left. They are even in Syria - without permission, of course. I guess when your fist is big enough you don't need permission. See Iraq.