Territorial demands

On 30 November 1939, Soviet forces invaded Finland with 21 divisions, totalling 450,000 men, marking the start of the Winter War between the Soviet Union and Finland, three months after the start of the Second World War.

Although technically a separate conflict, the war impacted and influenced events in the Second World War and both countries would find themselves drawn into the latter conflict.

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Disposition of Finish Units at the start of the Winter War.

The war occurred primarily due to the Soviet demands that Finland give up substantial areas along the border between the two countries – to rent Khanko Island and move the border 60km away from Leningrad - an important Russian Baltic Sea city and port - which lay 20 miles from Finland. The justification the Soviet Union gave for these demands was that it wished to improve the security of Leningrad.

If the Finns agreed to these demands, the Mannerheim Line, Finland's front line of defence, would lose the majority of its fortifications if it were to retreat from the Karelian Isthmus. Even if it were in exchange for twice as much Soviet land elsewhere,

Finland's population's reaction to the Soviet threats prevented the government from handing over all the islands to the USSR. Additionally, Finland's decision to maintain its neutrality with the other Scandinavian nations would be violated by the lease for a military installation at Hanko. How were the Finns to know if Stalin were to make additional demands after making and receiving his demands? 

Map detailing the direction of Soviet forces during the invasion and the territory ceded to the Soviet Union at the end of the Winter War. 

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Invasion

Talks between the two countries had lasted a year to no avail - when the Finnish government ultimately refused these demands, the Soviet Union invaded, after first conducting a False Flag operation in which they falsely accused the Finns of shelling the Soviet village of Mainila, in what became known as the ‘Shelling of Mainila’ (When in fact the Soviets themselves were responsible).

In response, the League of Nations declared the invasion an illegal act and expelled the Soviet Union, although this did nothing to stop the Soviets military action.

Many (although not all) reliable sources conclude that the Soviets actually intended to conquer all of Finland and annex the country completely or establish a puppet Finnish Communist government and indeed, the secret protocols of the Molotov-Ribbentrop pact (a secret agreement between Hitler’s Germany and the Stalin’s Soviet Union) seem to confirm these possibilities.

A Red Army tank advances in snow covered woodland during the conflict. The underequipped Finns initially struggled to counter the Soviets' tanks.

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The Soviet Union had a much larger and more powerful army than Finland – unsurprising given the size disparity between the two countries. On paper, its vast advantage in men and materials – particularly tanks and aircraft - should have made supressing Finland a relatively straightforward task.

The Finns had just 162 aircraft of various vintages compared to the Soviet attack's 3,000 modern and well-equipped aircraft. All the anti-tank guns the Finns owned had been delivered in the previous few days, and anti-aircraft weapons were equally sparse. The shortage of ammo was severe.

A Soviet soldier standing guard by the recently captured Finnish border checkpoint, 30 November 1939. 

The soldier is wearing a 'Budenovka' helmet - A Budenovka is a particular style of hat that was traditionally worn by Communist soldiers during the Russian Civil War that ensued after the Russian Revolution (1917–1922) and other conflicts. The "broadcloth helmet" was the item's official name.

On November 30, the Soviet Union deployed its 7th Army on the Karelian Isthmus, followed by its 8th, 9th, and 14th Armies, each of which had a different purpose. This amounted to 250,000 Red Army soldiers, each of whom had a different level of training and equipment, from well-equipped crack battalions to hastily put-together inexperienced rookies who had just been posted to the unit a few days before.

The blitzkrieg-style strategies that had been so successful for the Germans in Poland and Zhukov in Khalkin Gol were to be utilised by the Soviets using a sizable number of armoured formations and artillery pieces.

A Tupolev ANT-40 (Otherwise known as a Tupolev SB with unretractable ski gear. Note that the wheel bays are completely closed.

The most common Soviet bomber at the time was the SB. Used during the Spanish Civil War in 1936-39. the SB was a fast and well-armed bomber, but by 1939-40 it was becoming obsolete. At the war's outbreak, many units fitted their SBs with skis for operation from snow covered airfields, slowing the aircraft and making them more vulnerable, while the need to wear heavy winter clothing made the gunner's job even harder. December 1939 was a snowy month and both sides lost many crews on snowstorms, more than for enemy actions. The VVS lost at least five planes and crews (4 DB-3 of 1DB/5 OSAP and an I-15 bis) only on 30 November 1939 during snowstorms.

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The Soviets had an overwhelming air superiority, which included a range of modern aircraft as well as less capable models. In opposition to this, the Finns possessed a 160,000-strong force divided into units according to their home regions, no mobile armour, and a meagre number of vintage World War I biplanes.

Bombing of Helsinki

Three hours after the start of the war, the Soviets started to target the Finnish capital, Helsinki, with a series of bombing raids – eight in total. They dropped several hundred bombs on the city, killing 97 people, wounding 260 and destroying 55 buildings.

These actions – the bombings of a civilian area – were strongly condemned by the international community, and the President of the USA, Franklin D Roosevelt requested the Soviets cease these activities. In response, the Soviet Foreign Minister, Vyacheslav Molotov replied: 

Finnish Civilians enter a bomb shelter in Helsinki during a Russian air raid.

Julius Jääskeläinen

Finish Defence

However, the Finns offered fierce resistance, beating back the Soviet attempts for two months and inflicting heavy losses on the attacking forces. Furthermore, the battles often raged in sub-zero temperatures, sometimes dropping as low as −43 °C (−45 °F).

The fighting was mainly focussed on Taipale along the Karelian Isthmus, on Kollaa in Ladoga Karelia and on Raate Road in Kainuu, along with other fighting breaking out in Salla and Petsamo in the Lapland region.

Finnish soldiers pass a destroyed Russian vehicle during the Winter War.

Julius Jääskeläinen

After suffering damaging setbacks, the Soviets reorganised their forces, adjusted their tactics and renewed their offensive in February, gradually grinding down the outnumbered Finns and breaking through their defences.

Moscow Peace Treaty

The fighting eventually ended with the signing of the Moscow Peace Treaty in March 1940. Finland was forced to give up 9% of its territory (more than the Soviets originally demanded), including territories along the Lake Ladoga. Finland did retain its independence, however. The Soviet Union suffered a dent in its international status, given its aggressive actions and the poor initial performance of its military. This poor performance would have a direct impact on the ongoing Second World War as Hitler, having assessed the Soviet failures during the Winter War, decided that the Soviet military would be no match for the German Wehrmacht and that an invasion would be successful.   

Finnish flags lowered at half-mast in Helsinki on March 13, 1940, after the peace treaty became public.

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In June 1941, Hitler acted on his idea and – despite the existence of the Molotov-Ribbentrop pact – launched the Invasion of the Soviet Union – Operation Barbarossa in 1941. And fighting broke out once again between the Finns and Soviets with the Continuation War in 25 Jun 1941.