Russian Empire aftermath of World War I Kresy Belarus Soviet-Polish War World War I Soviet Union West Poland
The Soviet Union sought to re-annex some of territories that were under control of those states, formerly acquired by the Russian Empire in the centuries prior and lost to Russia in the aftermath of World War I; that included land such as the Kresy (Western Belarus and Western Ukraine) region ceded to Poland after losing the Soviet-Polish War of 1919–1921.