High Quality Content by WIKIPEDIA articles! The Winter War was fought in the four months following the Soviet Union's invasion of Finland on November 30, 1939. This took place three months after the German invasion of Poland that triggered the start of World War II. Sweden did not become actively involved in the conflict, but did indirectly support Finland. In the "Statsrådsdiktamen" on 19 February 1940, Sweden's king Gustav V publicly rejected pleas from Finland's government for military intervention in the Winter War to help defend Finland against the Soviet invasion. This statement from the king was aimed at pressuring Finland to accept harsh Soviet peace conditions and to quiet a strong Swedish activist public opinion advocating participation in the war.