소련·러시아는 기회가 생길 때마다 국경을 서쪽으로 옮기고 동유럽을 이용해 1차 방어선을 되도록 멀리 두려고 했다.
Whenever there was a chance, the Soviet Union, or Russia, tried to move the border to the west side, and keep the 1st line of defense as far as possible by using Eastern Europe.