Background of the Winter War

[5] In August 1939, the Soviet Union and Nazi Germany signed the Molotov–Ribbentrop Pact in which Eastern Europe was divided into spheres of interest.

The Finns sought aid from both the German Empire and the Bolsheviks to that end, and on 6 December 1917, the Finnish Senate declared the country's independence.

The Bolshevik leader, Vladimir Lenin, could spare no troops or attention for Finland, and so Soviet Russia recognised the new Finnish government just three weeks after it had declared its independence.

In 1918, the Finns fought a short civil war in which the Bolshevik Red Guards were armed by 7,000 to 10,000 Russian troops stationed in Finland.

The Communist Party of Finland was declared illegal in 1931, and the far-right Patriotic People's Movement (IKL) had won up to 14 seats in the 200-seat Finnish Parliament.

That participation in the Finnish struggle for independence created close ties with Germany, but after the German defeat, Scandinavian relations became more important and the main goal of Finland's foreign policy.

Finnish Nazis and ultranationalist parties such as the Patriotic People's Movement achieved only minor support in several elections, especially in the aftermath of the failed Mäntsälä rebellion in 1932.

Swedish–Finnish cooperation represented a rich vein of shared history in the culture of both nations, and the Swedish-speaking Finns had a common language with Sweden.

In the 1930s Finland purchased Thornycroft torpedo boats from the United Kingdom and refrained from buying bomber aircraft from Germany because of British protests.

[15] The Finnish Defence Forces called their military operation plan against the Soviet Union Venäjän keskitys ("Russian Concentration") in the 1920s.

The main defense line would be on the Karelian Isthmus; the Finnish forces would repel Soviet attacks in favourable positions and destroy the enemy by counterattacks.

In the Winter War, the VK2 scenario was flexible, with its basis proved to be correct, but the Finnish general staff badly underestimated the numerical superiority of the Red Army.

This led to a situation where officers were promoted very quickly and often commanders in middle and higher-ranks positions did not have enough experience and sufficient competence.

During the collectivization and the ethnic cleansing, the Soviets captured, killed and deported Ingrian peasants, which provoked widespread criticism by the Finnish media in 1930.

The Soviet Union used the Communist International to announce a doctrine in which bourgeoisie equalled fascism and that communism was the natural agency of the proletariat.

The Soviets considered that the empire had obtained an optimal balance of security and territory, and their thoughts were shaped by a historical precedent: the 1721 Treaty of Nystad, which was intended to protect Saint Petersburg from the Swedes.

[4] In 1938, Sweden was no longer a major threat to Russia, but the Soviets had not forgotten the role that the Finnish-controlled Åland islands had played as a base of operations for the German Expeditionary Force helping the Whites during the Finnish Civil War.

[2] In April 1938, a junior diplomatic official, Boris Yartsev, contacted Finnish Foreign Minister Rudolf Holsti and Prime Minister Aimo Cajander and stated that the Soviets did not trust Germany and that war was considered to be possible between the two countries in which Germany might use Finland as a base for operations against the Soviet Union.

[33] In the mid-1930s, the Soviet ambassador in Helsinki, Eric Assmus,[34] and the Leningrad Bolshevik Party leader Andrei Zhdanov[35] had presented a similar proposal.

The Soviets reduced their demands: a Red Army operation was no longer an option, and the focus was shifted on securing the Gulf of Finland.

The Soviets wanted to be informed of key elements of the Finnish–Estonian Gulf blockade, the secret military plan against the Baltic Fleet.

Many years later, the minister then in charge, Urho Kekkonen, admitted that it had been a simple gesture to suggest to Moscow that Finland did not harbour a German fifth column.

In addition, the violent collectivisation, the Great Purge, the show trials and the executions in the Soviet Union had given the country a very bad reputation.

The Finnish government sent its ambassador in Stockholm, Juho Kusti Paasikivi, instead of its foreign minister, Eljas Erkko, to limit his powers as a negotiator.

In exchange, the Soviets would cede Repola and Porajärvi from Eastern Karelia, an area twice as large as the territory demanded from the Finns.

On the Soviet side of the border, penal labour worked hard to add some density to sparse road and rail networks.

The Supreme Council of War ordered the Commander of Leningrad Military District Merestkov to draft an invasion plan, instead of Chief of Staff Boris Shaposhnikov.

[44] The necessary assault troop deployments and commands were not initiated until October 1939, but operational plans made in September called for the invasion to start in November.

Andrei Zhdanov had already commissioned a celebratory piece from Dmitri Shostakovich, Suite on Finnish Themes, to be performed as the marching bands of the Red Army would parade through Helsinki.

[48] On 30 November, Soviet forces invaded Finland with 27 divisions, totalling 630,000 men, bombed civilian boroughs of Helsinki and quickly reached the Mannerheim Line.