“History shows there are no invincible armies.”
—Russian Premier Joseph Stalin, Radio Broadcast, July
Not only did 1939 mark the year in which Nazi Germany invaded Poland, setting off World War II; it also was the year in which Joseph Stalin, General Secretary of the Soviet Union, decided that a buffer zone was needed for the important city of Leningrad, only 32 kilometers from the Finnish border. Just north of Leningrad lay the Mannerheim fortification line extending across the Karelian Isthmus. When negotiations between the Soviet Union and Finland broke down, the Soviets immediately attacked, confident they would be able to defeat the Finns within a couple of weeks.
Russian confidence was shaken by the fierce resistance put up by Finland, who quickly set aside political differences in order to defend their country. World sympathy lay with little Finland in the brief struggle known as the Winter War. Sweden and Norway sent volunteers and supplies to the out-matched Finns, and more materiel came from Britain and France, but the American arsenal yielded neither equipment nor supplies.
Despite international sympathy, small Finland could not withstand the giant USSR. The Soviets had four times as many troops, 100 times as many tanks, and 30 times as many aircraft as the Finns. The Winter War