By 1939, the Soviets demand the border be moved away from Leningrad and that Finland cede island in the Gulf of Finland. On November 30, 1939, the Soviet Union invaded Finland to take control of land the Soviets thought was critical for the defense of Leningrad.
Throughout the war, 1.5 million Red Army soldiers participated in the attack on Finland’s borders. With a Finnish force that peaked at 362,000 troops, a swift Soviet victory was expected. Few believed that the Finnish army stood any chance against one of the largest armies ever assembled. Soviet ground, naval, and air forces were vastly superior in size to the small Finnish forces.
While the Russians attacked all along the border, their main concentration of forces was north of Leningrad, on the Karelian Peninsula.
The winter in Finland from 1939 to 1940 was especially harsh and posed significant challenges to unprepared, poorly equipped and unmotivated Red Army forces. The Soviets felt they would roll over Finland in just three weeks and did not give their soldiers winter supplies. Soviets were impressed with German blitzkrieg tactics and wanted to replicate them in Finland.
By using unconventional tactics, and exploiting harsh Finnish climatic and geographic conditions, the Finns resisted the Russian ‘bear’ for three months in an offensive that Russian military planners had expected to last for only three weeks.
After repeated unsuccessful attempts to defeat the Finns using maneuver doctrine, the Soviets reorganized, retrained, and massed their forces on a narrow front. They then attacked, gradually exhausting the defending Finns.
Soviet losses were heavy, and the country's international reputation suffered. The Soviet losses were greatly disproportionate to what they actually gained through negotiated peace.
The Winter War (The Soviet-Finnish War) 1939-1940
