Quote Originally Posted by Hanna View Post
I realise they tried to take back what they thought was theirs
No. They wanted to protect Leningrad, because Soviet-Finn border was too close to the city and Finland was an ally of Germany. So in case of war finn troops could get to the city too fast and long-range artillery could been used without crossing border. There were long negotiations before this war, in which bigger territories of soviet land were proposed in exchange. Joseph Stalin said: "We can do nothing with geography. As well as you. We can't move Leningrad away from the border, so we'll have to move the border away". But Finland rejected everything. May be they hoped Germany won't let this war happen, but Hitler could not break the agreement with USSR - he was not yet ready to start the war yet.