Ka kammala wannan magana: A ranar 1 ga Satumba, 1939, Nazi Jamus ta mamaye Poland kuma ta soma Yaƙin Duniya na Biyu. A ranar 17 ga Satumba, 1939, Tarayyar Soviet, bisa ga yarjejeniyar sirri na Yarjejeniyar Molotov-Ribbentrop, ta mamaye Poland daga gabas. A cikin 'yan watanni, Tarayyar Soviet ta kaddamar da
yaƙi da Finland. Sakamakon wannan yaƙin, an tilasta wa Finland ta ba da ƙasa, gami da sassan lardin Viipuri, ga Tarayyar Soviet a cikin Yarjejeniyar Zaman Lafiya ta Moscow a farkon 1940. Finland ta rasa iyakokinta na asali tare da Kogin Rajajoki () a kudu. 22,973 km2, ko kashi 71.5 na lardin a kan Karelian Isthmus, gami da biranen Viipuri da Sortavala, sun zama wani ɓangare na sabon kafa Karelo-Finnish SSR a cikin Tarayyar Soviet. Bayan yarjejeniyar zaman lafiya, an kwashe dukkan mazaunan yankunan da aka ba su, sama da mutane dubu dari huɗu, zuwa tsakiyar Finland.