In the autumn of 1939, Finland faced a choice that other countries in the region managed to avoid – to accept the Soviet ultimatum and maintain the semblance of independence, or to refuse and deal with the consequences. As the only country in the Soviet sphere of influence, it chose resistance, starting one of the most unequal conflicts in 20th-century history.
The Cost of Being Part of an Empire
For over a hundred years, from 1809 to 1917, Finland functioned as a Grand Duchy within the Russian Empire. This long period of dependence shaped the way Soviet leaders thought about the region. To Stalin and his entourage, countries like Finland, Estonia, or Latvia were not sovereign states, but temporarily lost provinces that would sooner or later return to the motherland.
The Finnish-Soviet border ran just 32 kilometers from Leningrad, the second-largest city in the USSR and a major industrial hub. The Kremlin portrayed this proximity as a threat to state security, although in reality the Soviet Baltic Fleet completely dominated the German Navy in the area. The argument about defending Leningrad was mainly a convenient diplomatic pretext.
After regaining independence in 1917, Finland consistently built its position as a neutral country aligned with democratic Nordic states. Even during the Russian Civil War, it refused to allow White forces to use its territory, although this could have decided the outcome of the conflict. This neutrality, however, did not fit the Soviet vision for regional order.
The Pact that Redrew the Map of Europe
In the summer of 1939, the world stood on the brink of war, but few expected what happened on August 23. Ideological enemies, Nazi Germany and the Communist Soviet Union, signed a nonaggression pact. The official text of the document was fairly mundane. The real significance lay in a secret protocol that divided Eastern and Central Europe into spheres of influence.
Finland, the Baltic states, and the eastern half of Poland were assigned to the USSR. Hitler needed a free hand to attack Poland, while Stalin received carte blanche to rebuild the borders of the former empire. For the region’s small nations, this signaled the onset of dark times. Barely a month later, Germany and the Soviet Union together crushed Poland, and on September 28 specified the division of their spoils.
The Kremlin acted quickly. Between late September and October 1939, Lithuania, Latvia, and Estonia, under overwhelming military pressure, accepted Soviet ultimatums, permitting the Red Army to station troops on their soil. All three states lost their independence in less than a year. Finland was next in line, but its response was quite different.
The Ultimatum and Refusal
The demands presented on October 12, 1939, were precise and ruthless. Moscow wanted to shift the border 25 kilometers northwest, which meant ceding the fortified Karelian Isthmus along with the famous Mannerheim Line.
Additionally, Finland was to lease the Hanko peninsula for 30 years as a naval base. In return, it was offered a much larger but sparsely populated area of Karelian taiga – hardly an equivalent exchange.
Importantly, the USSR also demanded the dismantling of fortifications that shielded Finland from attack from the east. Accepting these conditions would have meant effectively abandoning any prospect of national defense. The Finnish government, led by Prime Minister Aimo Cajander and Foreign Minister Eljas Erkko, decided to refuse. This was an unprecedented decision in the geopolitical situation of the time.
It is worth remembering that Finland had a nonaggression pact with the USSR, signed in 1932 and extended in 1934 for another decade. Moscow unilaterally broke both agreements in autumn 1939, treating them as worthless scraps of paper. For Finnish politicians, it was clear that no concessions could guarantee their country’s safety.
The Mainila Provocation
Stalin needed a pretext to launch military actions, and the Soviet propaganda machine promptly provided one. On November 26, 1939, Red Army artillery shelled Mainila, a small village on Soviet territory right next to the Finnish border. The Kremlin then announced that Finnish guns were responsible for the attack, killing several Soviet soldiers.
The accusation was absurd. The Finns had already withdrawn artillery from the border area specifically to avoid such incidents and provocations. The Finnish command categorically denied any involvement in the shelling. Moscow demanded apologies and the withdrawal of Finnish troops 20–25 kilometers from the border, which would have meant giving up defensive fortifications. Helsinki refused.
The Mainila incident became the official justification for breaking the nonaggression pact and launching the invasion. Historians now unanimously agree that it was a classic false-flag operation, planned and executed by the Soviets. Stalin, however, believed that a strong push would be enough for tiny Finland to fall within weeks. He was gravely mistaken.
Blind Faith in a Quick Victory
One of the most fascinating aspects of Soviet preparations for war was the dramatic underestimation of Finland’s defensive capabilities. The Kremlin relied on information provided by the underground Finnish Communist Party, whose reports were formulated to match Moscow’s expectations. Telling unpleasant truths was hazardous to one’s health in Stalin’s USSR.
The Great Purge of 1937–1939 devastated the Soviet intelligence services. Both military intelligence (Razvedupr) and civilian intelligence (INO NKVD) lost many experienced officers, shot or sent to the gulag. Those who survived learned not to report anything contradicting the official line. As a result, Stalin planned the war based on a false picture of reality.
When, after three months of fierce fighting, it became clear that Finland was not only defending itself but inflicting heavy losses on the Red Army, the shock in the Kremlin was immense. Only then did the Soviet dictator realize the scale of his own miscalculation. The small democratic republic on Leningrad’s doorstep turned out to be a much tougher nut to crack than anyone in Moscow had expected.
Autor
Marcus Renfell
Marcus Renfell is a historian driven by curiosity and passion. He refuses to accept the “safe,” polished versions of the past. Instead, he brings forgotten, overlooked, and distorted stories back to life. His work blends scholarly precision with the art of storytelling, turning historical narratives into vivid, page-turning experiences.
His mission is simple: to prove that history can be gripping, alive, and deeply personal.
His debut book: Women of Science. Stories You Were Never Told
In his first publication, Marcus Renfell shines a light on the remarkable women who shaped the world of science — both the pioneers whose names we know and the brilliant minds history forgot. It’s an inspiring journey through untold stories, groundbreaking achievements, and the resilience of women who changed our understanding of the world.
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