Suomussalmi (December 7th, 1939 – January 8th, 1940) The greatest Finnish victory during the Winter War against the Soviet Union.
The defeat of Poland in the war against both the Third Reich and the Soviet Union, and the partition of the Polish state by the aggressors (the September 28 pact, 1939) completely changed the situation in this part of Europe. The Baltic Sea states: Lithuania, Latvia and Estonia, in accordance with the pact between Stalin and Hitler, found themselves placed under the Soviet sphere of influence and were quickly put under Moscow’s political and military control. According to this pact, also belonging to the Soviet zone was Finland, against which Stalin planned war. In October and November 1939 Moscow deliberately worsened its relations with Finland, accusing it of armed provocations and of planning aggression against the Soviet Union. On November 30th, 1939 Soviet troops crossed the border with Finland starting the Winter War.