The Winter War (also known as the Soviet-Finnish War or the Russo-Finnish War) broke out when the Soviet Union attacked Finland on November 30, 1939, three months after the start of World War II. As a consequence, the Soviet Union was expelled from the League of Nations on December 14th. Stalin had expected to conquer the whole country by the end of 1939, but Finnish resistance frustrated the Soviet forces, which outnumbered them three to one. Finland held out until March 1940, when a peace treaty was signed ceding about 10% of Finland's territory, and 20% of her industrial capacity, to the Soviet Union.
Franco-British preparations for support of Finland through northern Scandinavia (the Allied campaign in Norway), intended to occupy the Northern Scandinavia with its iron ore mines at the same time, became a strong reason for Nazi Germany's invasion of Denmark and Norway within a month after the war (Operation Weserübung). Furthermore, it has been persuasively argued that the poor showing of the Soviet forces had a significant effect on Adolf Hitler's decision to attack the Soviet Union in 1941 (Operation Barbarossa).
Although the Winter War typically is considered a military disaster for the Soviet Union, and indicative of an inherent weakness in the Soviet system, it may be noted that even the German Wehrmacht, as it would become apparent in 1941, was simply not prepared for offensive winter warfare. Neither would the armies of France, Britain, or USA have been.
Finland had a long history of being a part of the Swedish kingdom when it was conquered by Russia in 1808. Following the end of World War I, and the revolution that brought Soviet power to government in Russia, Finland had declared itself independent on December 6, 1917. The German–Finnish ties remained close, although Finnish sympathy for the National Socialists was very sparse. These strong ties were founded when Finland's underground independence movement during the First World War was supported by Imperial Germany. In the subsequent Civil War Germany-trained Finnish Jaeger troops and regular German troops played a crucial role. Only Germany's defeat in World War I hindered the establishment of a Germany-dependent monarchy under Väinö I of Finland.
The relationship between the Soviet Union and Finland was tense and frosty—both the two periods of forced russification at the turn of the century, and the legacy of the failed socialist rebellion in Finland contributed to a strong mutual distrust. Josef Stalin feared that Nazi Germany would attack sooner or later, and was keen to avoid a German attack on Leningrad (now: Saint Petersburg) via Finnish territory. In 1932, the Soviet Union signed a non-aggression pact with Finland. The agreement was reaffirmed in 1934 for ten years.
Nazi Germany and the Soviet Union had signed a mutual non-aggression pact, the Molotov-Ribbentrop Pact, on August 23, 1939. The pact also included a secret clause allocating the countries of Eastern Europe between the two signatories. Finland was agreed to be in the Soviet "sphere of interest". The German attack on Poland, September 1st, was followed by a Soviet invasion from the east. In a few weeks they had divided the country between them. The countries in the neighbourhood realized their fate could be the same. During the fall of 1939 Stalin demanded that Finland and the Baltic countries allow the Soviet Union to set up military bases on their soil - supposedly for defensive purposes. The Finnish government felt it had little alternative but to refuse Stalin's demands; on November 30 the Soviets attacked with 23 divisions, totalling 450,000 men, which quickly reached the Mannerheim Line. The war was based on a bogus border incident - the so-called Shelling of Mainila where Soviet claimed losses from artillery firing, blaming it on the Finns. While the claims have never been considered credible by the Finns, they were only recently proved false by formerly classified documents.
A puppet regime was created in the occupied Finnish border town of Terijoki (now Zelenogorsk) on December 1, 1939, under the auspices of the Finnish Democratic Republic and headed by Otto Ville Kuusinen for both diplomatic purposes (it immediately became the only government for Finland that was recognized by the Soviet Union) and for military ones (it was hoped to cause socialists in Finland's Army to defect). It was not particularly successful. This republic existed until March 12, 1940, and was eventually incorporated with the Russian Karelo-Finnish SSR.
Initially Finland had a mobilized army of only 160,000 men, but the Finnish troops turned out to be a fierce adversary employing guerrilla tactics, fast-moving ski troops in white camouflage suits, and capitalizing on their local knowledge. A certain improvised petrol bomb adapted from the Spanish Civil War was used with great success, and gained fame as the Molotov cocktail. The conditions of the winter 1939/40 were harsh; temperatures of -40°C were not unusual, and the Finns were able to use this to their advantage.
In addition, to the surprise of both the Soviet leadership and the Finns, it turned out that the majority of the Finnish Socialists did not support the Soviet invasion but fought alongside their compatriots against the common enemy. Many Finnish Communists had moved to the Soviet Union in the 1930s to "build Socialism," only to end up as victims of Stalin's Great Purges, which led to widespread disillusion and even open hatred of the Soviet regime among Socialists in Finland. This partial healing of the wounds and rifts after the Civil War in Finland (1918), and Finland's language strife, is still referred to as "the Spirit of the Winter War," although it should also be noted that many communists were not allowed to fight in Finland's conscription army because of their political background.
Soviet arrogance and/or incompetence was an important factor. The attackers weren't expecting much of a struggle, and due to Stalin's purges, the commanders of the Red Army had suffered 80% peacetime losses. These were commonly replaced by people less competent but more pleasing to their superiors, and tactics which were obsolete by World War I were sometimes witnessed. Tactics were strictly "by the book," as a failed initiative otherways carried a high risk of execution. The Soviet army was also far less well prepared for winter warfare, particularly in forests, and heavily used vulnerable motorized vehicles. The so-called "Raatteentie Incident," during the month-long Battle of Suomussalmi, where one Soviet division was defeated after marching on a forest road straight into an ambush with vastly outnumbered Finnish soldiers, is still used in military academies as an example of what not to do.
The Finnish equipment shortage is also worth noting. At the beginning of the war, only those soldiers who had been receiving basic training had uniforms and weapons. The rest had to make do with their own clothing with a semblance of insignia added and, in some cases, with their own guns. These mismatched "uniforms" were nicknamed "Model Kajander" after the Prime Minister Aimo Cajander. The Finns tried to alleviate the shortages by making extensive use of the equipment, weapons and ammunition captured from the enemy. Fortunately, the army had not changed the caliber of its weapons after independence and was able to use Soviet ammunition.
World opinion at large supported the Finnish cause. The World War hadn't really begun yet; for the time being the Winter War was the only real fight going on, on which the world's interest was focused. The Soviet aggression was generally deemed totally unjustified. Various foreign organizations sent material aid, such as medical supplies. Finnish immigrants in the United States and Canada returned home, and many volunteers travelled to Finland (one of them actor-to-be Christopher Lee) to join Finland's forces: 1,010 Danes, 695 Norwegians, 372 Ingrians, 346 Finnish expats, and 210 volunteers of other nationalities made it to Finland before the war was over. Foreign correspondents in Helsinki wrote, and even greatly exaggerated, reports of supposed Finnish ingenuity and successes in combat.
Sweden, which had declared herself to be a non-belligerent rather than a neutral country (as in the war between Nazi Germany and the Western Powers) contributed with military supplies, cash, credits, humanitarian aid and some 8,700 Swedish volunteers prepared to die for Finland. Maybe most significant was the Swedish Voluntary Air Force, in action from January 7, with 12 fighters, 5 bombers, and 8 other planes, amounting to a third of the Swedish Air Force of that time. Volunteer pilots and mechanics were drawn from the ranks. The renowned aviator Count Carl Gustav von Rosen, related to Hermann Göring, volunteered independently. There was also a volunteering work force, of about 900 workers and engineers.
The Swedish Volunteer Corps with 8,402 men in Finland, and with the only common volunteers who had finished training before the war ended, started to relieve five Finnish battalions at Märkäjärvi in mid-February. Together with three remaining Finnish battalions, the corps faced two Soviet divisions and were preparing for an attack by mid-March, which was inhibited by the peace. 33 men died in action, among them the commander of the first relieving unit, Leutenant Colonel Magnus Dyrssen.
The Swedish volunteers remain a focus of dissonance between Swedes and Finns. The domestic debate in Finland had in the years immediately before the war given common Finns hope of considerably more support from Sweden, such as a large force of regular troops, that could have had a significant impact on the outcome of the war — or possibly caused the Russians not to attack at all. Since more substantial support was expected, Finnish evaluations of gifts, credits and volunteers from Sweden tend to be made on the foundation of deep and bitter disappointment.
Franco-British plans for a Scandinavian theatre
Already within a month, the Soviet leadership began to consider abandoning the operation, but Finland's government was reached by a preliminary peace feeler (via Sweden's government) first on January 29. Until then, Finland had factually fought for its existence. When credible rumours reached the governments in Paris and London, the incentives for military support were dramatically changed. Now Finland fought "only" to keep as much as possible of her territory in Leningrad's neighbourhood. But of course the public could know nothing about this — neither in Finland, nor abroad. For public opinion, Finland's fight remained a life and death struggle.
In February 1940 the Allies offered to help: The Allied plan, approved on February 5 by the Allied High Command , consisted of 100,000 British and 35,000 French troops that were to disembark at the Norwegian port of Narvik and allegedly support Finland via Sweden while securing the supply routes along the way. The plan was agreed to be launched on March 20 under the condition that the Finns plead for help. It was hoped that this would eventually bring the two still neutral Nordic countries, Norway and Sweden to the Allied side — by strengthening their positions against Germany, although Hitler already in December had declared to the Swedish government that Western troops on Swedish soil immediately would provoke a German invasion.
However, only a small fraction of the troops was intended for Finland. Proposals to enter Finland directly, via the ice-free harbour of Petsamo, were dismissed. Suspicions that the objective of the operation was to capture and occupy the Norwegian shipping harbour of Narvik and the vast mountainous areas of the North-Swedish iron ore fields from where the Third Reich received a large share of the iron ore critical for the war production, and fear of thereby becoming the battle ground for the armies of the Allied and the Third Reich, caused Norway and Sweden to deny transit. After the war it became known that the commander of the Allied expedition force actually was instructed to avoid combat contact with the Soviet troops.
The Franco-British plan initially hoped to capture all of Scandinavia north of a line Stockholm–Göteborg or Stockholm–Oslo, i.e. the British concept of the Lake line following the lakes of Mälaren, Hjälmaren , and Vänern, which would contribute with good natural defence some 1,700–1,900 kilometres south for Narvik. The expected frontier, the Lake line, involved not only Sweden's two largest cities, but its consequence was that the homes of the vast majority of the Swedes would be either Nazi-occupied or in the very war zone. Later the ambition was lowered to only the northern half of Sweden and the rather narrow adjacent Norwegian coast.
The Swedish government, headed by Prime Minister Per Albin Hansson, declined to allow transit of armed troops through Swedish territory. Although Sweden had not declared herself neutral in the Winter War, she was neutral in the war between France and Britain on one side and the Third Reich and the Soviet Union on the other. Granting transit rights to a Franco-British corps were at that time considered too great a diversion from international laws on neutrality.
The Swedish Cabinet also decided to reject repeated pleas from the Finns for regular Swedish troops to be deployed in Finland, and in the end the Swedes also made it clear that their support in arms and munitions could not be maintained for much longer. Diplomatically, Finland was squeezed between Allied hopes for a prolonged war and Scandinavian fears of a continued war spreading to neighbouring countries (or of the surge of refugees that might result from a Finnish defeat). Also from Wilhelmstrasse distinct advice for peace and concessions arrived — the concessions "could always later be mended."
While Berlin and Stockholm pressured Helsinki to accept peace also on bad conditions, Paris and London had the opposite objective. From time to time, different plans and figures were presented for the Finns. To start with, France and Britain promised to send 20,000 men to arrive by the end of February, although under the implicite condition that on their way to Finland they were given opportunity to occupy North-Scandinavia.
By the end of February, Finland's Commander-in-Chief, Field Marshal Mannerheim, was pessimistic about the military situation, which is why the government on February 29 decided to start peace negotiations. That same day, the Soviets commenced an attack against Vyborg.
When France and Britain realized that Finland was seriously considering a peace treaty, they gave a new offer for help: 50,000 men were to be sent, if Finland asked for help before March 12. But actually, only 6,000 of these would have been destined for Finland. The rest was intended to secure harbours, roads and iron ore fields on the way.
By the end of the winter it became clear that the Russians had had enough, and German representatives suggested that Finland should negotiate with the Soviet Union. Russian casualties had been high and the situation was a source of political embarrassment for the Soviet regime. With the spring thaw approaching, the Russian forces risked becoming bogged down in the forests, and a draft of peace terms were presented to Finland on February 12. Not only the Germans were keen to see an end to the Winter War, but also the Swedes, who feared a collapse in Finland. As Finland's Cabinet hesitated in face of the harsh Soviet conditions, Sweden's King Gustaf V made a public statement, in which he confirmed to have declined Finnish pleas for support by regular troops.
By the end of February, the Finns had depleted their ammunition supplies. Also, the Soviet Union had finally succeeded in breaking through the previously impenetrable Mannerheim Line, against which they suffered most of their casualties. Finally on February 29 the Finnish government agreed to start negotiations. The Finnish government proposed an armistice March 5, but Soviets wanted to keep pressure on and declined the offer next day, and the fighting continued to the day peace treaty was signed. After four months of fighting, at least 49,000 Russian soldiers had lost their lives. Finnish losses had been limited to around 27,000 men, but peace still came at a high price for the Finns.
Peace of Moscow
In the Moscow Peace Treaty of March 12 Finland was forced to cede the Finnish part of Karelia (with Finland's industrial center, including Finland's second largest city Viipuri, in all nearly 10% of the territory), even though large parts still were held by Finland's army. Some 422,000 Karelians, 12% of Finland's population, lost their homes. Military troops and remaining civilians were hastily evacuated to avoid becoming subjects of the Soviet Union.
Finland also had to cede a part of the Salla area, the Kalastajansaarento peninsula in the Barents Sea and four islands in the Gulf of Finland. The Hanko Peninsula was also leased to the Soviet Union as a military base for 30 years.
The Finns were shocked by the harsh peace terms. It seemed as if more territory was lost in the peace than in the war. Sympathy from world opinion, and from the Swedes in particular, seemed to have been of little worth. For better or worse, the harsh terms drove the Finns to seek support from the Third Reich and made many Finns regard revenge as justified.
Only a year later hostilities resumed in the Continuation War.