The Continuation War was a conflict fought by co-belligerents Finland and Nazi Germany against the Soviet Union (USSR) from 1941 to 1944 during World War II. In Russian historiography, the war is called the Soviet–Finnish Front of the Great Patriotic War. Germany regarded its operations in the region as part of its overall war efforts on the Eastern Front and provided Finland with critical material support and military assistance.
The Continuation War began 15 months after the end of the Winter War, also fought between Finland and the USSR. There have been a number of reasons proposed for the Finnish decision to invade, with regaining territory lost during the Winter War being regarded as the most common. Other justifications for the conflict included President Ryti's vision of a Greater Finland and Commander-in-Chief Mannerheim's desire to liberate Karelia. Plans for the attack were developed jointly between the Wehrmacht and a small faction of Finnish political and military leaders with the rest of the government remaining ignorant. Despite the cooperation in this conflict, Finland never formally signed the Tripartite Pact that had established the Axis powers and justified its alliance with Germany as self defense.
In June 1941, with the start of the German invasion of the Soviet Union, the Finnish Defence Forces launched their offensive following Soviet airstrikes. By September 1941, Finland occupied East Karelia and reversed its post-Winter War concessions to the Soviet Union along the Karelian Isthmus and in Ladoga Karelia. The Finnish Army halted its offensive past the old border, around 30–32 km (19–20 mi) from the center of Leningrad and participated in besieging the city by cutting its northern supply routes and digging in until 1944. In Lapland, joint German–Finnish forces failed to capture Murmansk or cut the Kirov (Murmansk) Railway, a way point for lend-lease equipment to the USSR. The conflict stabilised with only minor skirmishes until the tide of the war turned against the Germans and the Soviet Union's strategic Vyborg–Petrozavodsk Offensive crushed Finnish resistance in June 1944. The attack drove the Finns from most of the territories they had gained during the war, but the Finnish Army managed to halt the offensive in August 1944.