The Russian civil war gave Poland the chance to regain the land controlled by the Polish-Lithuanian Commonwealth that was taken by Russia during the split up of Poland. Meanwhile, the Soviet leaders wanted to respond to the leader of Poland, Józef Piłsudski's, moves into Ukraine, by attacking Poland, which the Soviets saw as a land bridge to Western Europe, that they could cross to expand Communism to the west. This started the Polish-Soviet war and ended in a victory for Poland after the battle of Warsaw, which made both sides, want to end the war. More defeats after the defeat near Warsaw made the Soviets want to end the war. The Poles, under pressure by the League of Nations, also wanted to end the war after they had taken a lot of land and their army was tired.