The land originally belonged to Germany, who made a vow to never expand their borders beyond a certain eastern point after reunification. So only Russia really

The land originally belonged to Germany, who made a vow to never expand their borders beyond a certain eastern point after reunification. So only Russia really had a claim to it. https://en.wikipedia.org/wiki/Treaty_on_the_Final_Settlement_with_Respect_to_Germany https://en.wikipedia.org/wiki/Treaty_on_the_Final_Settlement...