Well, Russia has been repeatedly invaded. Overrun by the Mongols. The French, the Germans, the British, the Germans again. And threatened with nuclear attack by the US, after Japan surrendered. So they're paranoid, perhaps understandably.
While rudely stated, The factual content of rijrjrgyg's post is an undeniable outrage of history "Losing statehood" would, in comparison, be a walk in the park.
"World War II casualties of the Soviet Union":
https://en.wikipedia.org/wiki/World_War_II_casualties_of_the...
So, no, Russia's WWII losses don't make Poland's problems a "walk in the park".
You know, if they wouldn't try to capture Iran for themselves, they wouldn't be threatened with nuclear attacks.
Don't portrait USSR or Russia as purely innocent entities.
PS and invasion by Britain (if you're talking about Crimean war) was after Russian Empire broke the treaty by attacking Turkey.