Winter War, whiles knawn as the Forst Soviet-Finnish War an aa, wes a war atween the USSR and Finland. Eftor the war, Finland lost Karelia te the USSR and the region remains a pairt o the Russian Federation the day. The war began wi the Soviet invasion o Finland o the 30 Novembor 1939 (three month eftor the ootbrik o World War II), and ended wi the Moscow Peace Treaty o the 13 Mairch 1940. The League o Nations deemed the attack illegal and buited the USSR oot o the League o the 14 Decembor 1939.
The Soviets myed sindry demands o the Finns, sic as Finland sud exchange muckle border territories for lands iv uthor airts. The Soviets claimed security reasons – abuin aa, the protection o Leningrad, that wes nobbut 32 km (20 mi) frae the Finnish border. When Finland refused, the Soviets invyeded. Myest soorces hes concluded that the Soviet Union forst ettled te conquer the hyel o Finland afore sattlin wi nobbut the annexation o Karelia. The establishment o the puppet Finnish Communist govrenment and the Molotov–Ribbentrop Pact's secret protocols is byeth coonted as evidence o this, hooanivvor, uthor sources hes argied agyen this idea. Finland defended itsel agyen Soviet attacks for mair nor twe month an inflicted muckle losses o the invaders i wintor temperaturs at wes whiles as law as −43 °C (−45 °F).
The battles wes myestly focused o Taipale alang the Karelian Isthmus, o Kollaa i Ladoga Karelia an o Raate Road i Kainuu, but thor wes battles i Salla an Petsamo i Lapland an aa. Eftor the Soviet military reorganised an adopted better tactics, they renewed thor offensive i February an owercam the Finnish defences.