Finland was invaded by the Soviet Union exactly 85 years ago. On November 30, 1939, a Soviet force of 120,000 troops, 1,000 tanks, 600 artillery pieces and planes crossed the frontier with Finland. The army of Finland was vastly outnumbered and outgunned with only 33,000 men, fewer than 70 aircraft and a dozen tanks. With such overwhelming odds, Stalin expected to overrun Finland in two weeks, but his army was ill equipped, badly trained and the invasion poorly planned.
That winter in Finland was also severe but the Finns were used to intense cold. They wore winter clothing and white camouflage to blend in with the snow, could navigate through forests on skis, were excellent marksmen and were highly motivated. With few good roads, the Soviet forces were often trapped in traffic jams, leaving them open to ambush by an unseen enemy hiding in snow and forests. They had poor clothing, their tanks and transports became snarled up in deep snow, fuel froze and guns became jammed. The Finns used guerrilla tactics, making lightning attacks on skis, targeting the Soviet army’s supply lines — especially their food and shelters — while destroying tanks and artillery pieces with improvised weapons such as petrol bombs.
The Russians suffered immense casualties, but in February 1940 they used sheer force of numbers to launch a huge offensive that crushed Finnish positions until their defences fell. The Finns had hoped that a spring thaw would bog down the Soviet advance in mud and water, but by mid-March the Finns were exhausted and asked for a ceasefire. They had lost 69,000 killed or wounded and the hoped-for help from western Allies failed to materialise. The war ended on March 13 after more than three months in which Soviet losses were staggering — an estimated half a million killed or wounded, and 700 planes and 2,300 armoured vehicles destroyed.
Finland kept its independence but lost over a tenth of its territory, with 400,000 citizens displaced. The Soviet losses led Stalin to reorganise and re-equip his army, but its poor performance in Finland encouraged Hitler to invade Russia in 1941, only for him to underestimate the severe Russian winter.