Finland has always maintained a neutral attitude during World War II. It is a neutral country and did not assist any party participating in the war. During World War II, Finland and the Soviet Union fought two wars, the Winter War and the Continuation War.

During World War II, Finland and the Soviet Union fought twice: the Winter War from 1939 to 1940 (in this war, Sweden provided partial assistance to Finland, and under the leadership of Marshal Mannerheim, it set a record The classic of defeating more with less) and the Continuation War from 1941 to 1944 (Nazi Germany provided important help to Finland, and the Finns recovered the Karelia region through this war).

Finland maintained a neutral attitude during World War II. In 1944, the Soviet Union launched a counterattack and reoccupied the territory recaptured by Finland.

During the Battle of Lapland from 1944 to 1945, Finland drove the Germans out of northern Finland.

Many treaties signed with the Soviet Union in 1947 and 1948 stipulated Finland's obligations and restrictions towards the Soviet Union. Finland also made more territorial concessions based on the 1940 peace treaty. After the collapse of the Soviet Union in 1991, Finland was finally able to decide its own destiny and joined the European Union in 1995.