Posted on November 30, 2019December 1, 2019 by Erik Chipchase The old man does not care if you have a permit! Mannerheim wants you people off the lawn, Pronto! The Winter War was a military conflict between the Soviet Union and Finland. It began with a Soviet invasion of Finland on 30 November 1939, three months after the outbreak of World War II, and ended three and a half months later with the Moscow Peace Treaty on 13 March 1940.