The Russo-Polish War (1920) was a conflict between the newly established Second Polish Republic and the Soviet Union. It arose from territorial disputes following World War I, as both nations sought to expand their influence in Eastern Europe. The war was marked by significant battles, including the decisive Battle of Warsaw, where Polish forces successfully defended their capital. The conflict ended with the signing of the Treaty of Riga in 1921, which divided disputed territories between Poland and the Soviet Union. This war played a crucial role in shaping the borders and political landscape of Eastern Europe in the interwar period.