The Soviet-Finnish War was a war between the Soviet Union and Finland at the beginning of the Second World War, the Soviet-Finnish War broke out on November 30, 1939, the Soviet Union first launched an attack on Finland, although the Soviet Union won, but the casualties were heavy, and the planned purpose was not achieved, because the gap between the strength of the two sides was too large, the final armistice peace talks or Finland cut land reparations, and then on March 13, 1940, the two sides signed the "Moscow Peace Agreement" marked the end of the first phase of the war.
Finland was originally part of the Russian Empire, due to the First World War, Russia's national strength was greatly damaged, the Soviet Union was established at the same time, Finland also took the opportunity to become independent, since the establishment of the Soviet Union, the border between the Soviet Union and Finland has been controversial, and Finland has a close relationship with Germany in the process of independence, so the Soviet Union regards it as a possible accomplice of Germany, and the two sides have maintained a tense confrontation for more than a decade.
The Soviet Union has been negotiating, threatening, and supporting parties against the Finnish government to solve the border problem, and if necessary, to directly recover Finland through military operations, directly annexing the territory or making it a vassal state, while the Finnish government is resolutely independent, saying that the Soviet Union regards itself as the greatest enemy and the only enemy, and continues to avoid war by diplomatic means. From 1930 onwards, finland and Germany had been in close contact with Germany until the outbreak of World War II, and when Germany blitzed Poland, the Soviet Union was more worried about Finland becoming an ally of Germany, so on November 26, 1939, it declared war on Finland on the grounds of "Finnish shelling Soviet personnel".
The Soviet Union launched a full-line offensive on the Soviet-Finnish border, and the League of Nations, which maintained international order at the time, regarded the operation as an illegal attack and kicked the Soviet Union out of the League of Nations on December 14.
The Soviet army had an overwhelming superiority in strength and armament, but shortly before the war, the Soviet high level had just undergone a political purge, so when the Soviet Union invaded Finland, the Soviet army seriously lacked commanders, most of them were inexperienced new officers who had just taken office, which also led to the soviet tactics in the early days of the Soviet-Finnish War, the Soviet Union was clumsy in tactics, suffered great losses, and Finland also showed a resistance beyond the Imagination of the Soviet Union.
Helplessly, the gap between the strength of the Two Countries is too large, it is no longer tactical, the will to fight can not make up, in the late stage of the Soviet-Finnish War, the Soviet army replaced several capable commanders, and finally broke through the Finnish defense line, so Finland was forced to ask the Soviet Union for peace, and on March 13, 1940 signed the "Moscow Peace Agreement", Finland ceded about 10% of the territory, and 30% of the country's assets were compensated to the Soviet Union, the Soviet-Finnish War, the first phase was ended.
Finland maintained its independence and won international prestige, while the Soviet Union invested a huge number of troops but suffered heavy losses, the country's reputation was greatly damaged, and the original plan to occupy all of Finland ended up occupying only 10% of the territory. The Soviet-Finnish War had a great impact on the course of World War II, and the Soviet Union's performance in Finland also made Germany more convinced of its determination to defeat the Soviet Union, and began to contact Finland to let Finland join the plan to fight against the Soviet Union.
Then, at the end of June 1941, the "Continuation War" broke out, Finland and Germany sent troops to try to retake the land occupied by the Soviet Union, and the final result was that on September 19, 1944, the Soviet Union negotiated a peace armistice, Finland and Germany broke diplomatic relations, and at the same time, on the basis of returning to the border line of the first phase of the Soviet-Finnish War, Ceded the Portsamo region to the Soviet Union.