Germans suffered TWO humiliating defeats in world wars and had to go through painful transformation processes for decades. On top of that they’ve had support of western world.
Russians revel in numbers they’ve lost. 20 millions dead across Soviet Union? Who gives a shit? Можем повторить! (We can do it again!).
So long as kleptocracy is alive in Russia - it will never change. And this won’t happen in our lifetime.
US had to withdraw from Vietnam after humiliating defeat against Vietcong and Chinese/Soviet supplied Vietnam army after huge backlash from general population, as far as I know.