WSoviet Union in World War IIWBackground of the occupation of the Baltic statesWGerman–Soviet Frontier TreatyWBattles of Khalkhin GolWKurapatyWMolotov–Ribbentrop Pact negotiationsWGerman–Soviet military parade in Brest-LitovskWSoviet occupation of the Baltic states (1940)WShelling of MainilaWSoviet invasion of PolandWSoviet–Estonian Mutual Assistance TreatyWSoviet–Latvian Mutual Assistance TreatyWSoviet–Lithuanian Mutual Assistance TreatyWWinter War