Diplomatic relations between the two states were broken off several times during the twentieth century. The first came on 29 November 1939 with the outbreak of the Winter War between the USSR and Finland. With the negotiated conclusion to the war, diplomatic relations resumed on 12 March 1940. Relations were once more interrupted on 22 June 1941, with the Axis invasion of the Soviet Union and Finland's participation on the Eastern Front against Soviet forces as part of the Continuation War. With the defeat of the Axis powers in the Second World War, diplomatic relations were once more reestablished on 6 August 1945, and on 18 July 1954 the mission was upgraded to the level of an embassy. Following the dissolution of the Soviet Union in 1991, Finland recognized the Russia Federation as its successor state on 30 December 1991, and ambassadors have continued to be exchanged between the two countries.