On January 21, 1932, the Soviet Union and Finland signed a non-aggression pact. In spite of this pact, on November 30, 1939, the Soviet army invaded Finland, starting the so-called “Winter War.”
Before the October revolution of 1917 in Russia, Finland had been a part of the Russian Empire. The country received independence from the Bolsheviks, but in the Civil War which took place in Finland in 1918, the Communists suffered a defeat, straining the relations between the Soviet Union and Finland. Finland was afraid of Soviet aggression, and the Soviet Union feared that in case of war, Finland would give the enemies of the Soviet Union an opportunity to attack from Finnish territories.
On July 10, 1931 the government of Finland created the Defense Council, headed by Carl Mannerheim. Mannerheim was sure that the Soviet Union was an unpredictable and dangerous country, calling the Communists “the eastern plague.” In August 1939, the Soviet Union and Nazi Germany signed the Molotov–Ribbentrop Pact. It was a non-aggression treaty with a secret protocol about “spheres of interest” in it. According to that protocol, Finland fell into the Soviet sphere of interest.
On October, 5, 1939, the Finnish delegation, headed by J. Paasikivi, came to Moscow for negotiations. The reason for negotiations was the location of the border between Finland and the Soviet Union. Stalin thought the border was too close to Leningrad and asked the Finnish government to move it.
“Both of us can’t go against geography,” Stalin said, “and it is not possible to move Leningrad instead.” In addition, Stalin wanted to lease the Hanko peninsula and to establish a military base on it. In exchange, Stalin offered to Finland some lands in North Karelia, in the north of Russia.
Before the negotiations, Paasikivi had been instructed to reject all offers, and so he did. Both the Soviet Union and Finland started mobilizing. On November 3, the Soviet Union declared: “We, the civilians, did not achieve any progress. We should call the soldiers to speak.”
On November 26, near the village of Mainila, a border incident took place. A Soviet border guard post was shelled, and Soviet Foreign Minister Vyacheslav Molotov claimed it was a Finnish artillery attack. More than likely, it was a Soviet provocation to renounce the non-aggression pact with Finland, but in the following years, Soviet historiography remained silent about this version of events.
On November 30, Soviet troops received the order to attack. Khrushchev in his memoirs wrote what Stalin had said about Finland that day: “We shall just raise our voices a bit, and the Finns will give up.”
Stalin was not right. It was a short but cruel war.
The main Finnish defense line, known as the “Mannerheim line,” went across the Karelian Isthmus. The landscape of the Isthmus served as a basis for fortification. The features of Karelian nature are the great amount of big boulders, lying here and there, rocks and the stony chines hidden in the forests. In addition, there are many lakes, rivers and swamps in Karelia.
The Belgian General Badu wrote, “Nowhere else in the world were the natural conditions as good for building fortification as in Karelia.” The Mannerheim line was about 100 kilometers wide and consisted of three zones. The first zone, the operational defensive area, was about 40 kilometers wide. It took 10 days for the Soviet army to pass it – there were minefields, abatises and barbed-wire obstacles. There were about 200 mines per kilometer of every road. In addition, the Finns dug holes 7-10 meters deep into the roads and put the explosives in them – about 200 kg of explosive in a hole.
The second zone, the main defense zone, consisted of 22 defensive posts. There was a system of permanent fire positions and fire trenches. All permanent fire positions were protected from tanks and from infantry by barbed-wire obstacles and guard rail posts. For example, one of them had 45 rows of barbed wire attached to iron posts around it.
In the third zone were placed the tactical reserves. The ammunition was kept there, and the reserve troops based there.
The Soviet command had no definitive information about it and did not consider it.
The battles on the Karelian Isthmus were the hardest battles in that war, because the Soviet troops were not ready for the “Mannerheim line.” Only in the middle of December did the Soviet army break through the security area of the line, but could not go any further. Some historians say that the main reason for the failures of Soviet army was the weather. The winter of 1939-1940 was very cold – about 40 degrees below zero and the snow was waist-high.
Finns used the tactics of guerilla war. Small squads of skiers, armed with machineguns, attacked Soviet troops at night and withdrew to the forests after the attacks. In the opinion of the majority of Soviet soldiers, the greatest danger came from “cuckoos” – Finnish snipers who hid in the trees. They killed commanders and, according to some historians, destroyed the field-kitchens.
However, the Soviet army broke through the Mannerheim line in February 1940. The Soviet Union was able to occupy the country and change the government, so Finland asked for peace. The peace treaty was signed on March, 12, 1940. The three-month war took the lives of 67,000 Finnish soldiers. On the Soviet side, 48,475 died and 158,863 were injured.
Because of this war, the Soviet Union was expelled from the League of Nations, and the United States stopped selling aeronautic technologies to the Soviet Union. However, this decision did not do much harm to the Soviet aeronautic industry.