The winter war was a fight between the Soviet Union and Finland during WW2. It started the 30 of November 1939; only 3 month after WW2 started. It lasted three and a half months and ended 13 March 1940 with the Moscow Peace Treaty. The war started because the Soviets wanted Finnish territory in exchange for land elsewhere. However Finland refused and USSR invaded the country. There were many casualties during the war and at least 80,000 lost on both sides. After the Moscow Peace Treaty was signed, Finland relinquished 11% of its territory. After, Finland was able to retain its Sovereignty and enhanced international reputation. Unfortunately, the bad performance of the Red Army, made Nazi leader Adolf Hitler think attacking them would be successful; also known as Operation Barbarossa. This failed and the USSR ended up joining the Allies in WW2.