Russias conquered landmass is surrounded by suppressed ethnicities with an axe to grind. You do not get to have a moment of weakness in that region. You have a moment of weakness and then the aserbeidschanis, the turks, the chechyans and the chinese jump you and turn the yalu river red. Russias benefit was the tech transfer from europe to always stay ahead of the competition. They can not have a peaceful europe.