NightFox
Wildling
Night Fox -
Finland actually fought two wars against the Soviet Union - the Winter War and the Continuation War.
At the end of the Winter War Finland had pushed the Soviets back almost to Leningrad. Much of those gains were then lost in the Continuation War.
But the major loss of land for Finland occured after WWII, when the western world rewarded Stalin by allowing him to seize and keep a massive chunk of Finnish land, known as the "ladies right arm" for its shape.
Yes sir, that's what I pointed out the Winter War (pre Operation Barbarossa) and The Continuation (post German Invasion), at the end of the Winter War the Finnish ceded Territory to the Soviets, which IMHO was only possible due to the Zhukov faction of the Soviet High Command coming to prominence after the Pavlov faction was discredited by Finnish military successes. At the conclusion of The Winter War (1940) Finland ceded large areas of Karelia and Salla to the Soviets (approximately 10% of their pre-war territory), the Finnish didn't win the Winter War they lost it.
During The Continuation the Finnish pushed all the way to the Leningrad District (primarily due to the fact that the Soviets had their hands full with the Germans) however they were soundly defeated and driven back to approximately their original Winter War line of defense by a Soviet Offensive in 1944 (despite being heavily resupplied by the Germans), at the conclusion of WW II the Finnish were forced to pay reparations to the Soviets (Finland having sided with Germany during Operation Barbarossa).
However IMHO it's likely that Finland's efforts were successful in keeping it from avoiding the same fate as the Baltic States (annexation by the Soviet Union) given that it's fairly clear that was Stalin's intention from the outset. All in all IMHO the whole story is a fascinating sub-plot of WW II that many people seemed to have missed in history class.