[DiogenesKynikos]

> Another central tenet of both Nazism and Bolshevism is their hatred for capitalism and democracy.

Nazi Germany was a capitalist country. The reason why German conservatives brought the Nazis into government was in order to smash the German socialist and labor movement. Portraying Nazi Germany as anticapitalist is deeply ahistorical.

Your argument, that the repression carried out in Poland and the Baltics by the USSR proves it wasn't motivated by fear of Germany, does not logically follow.

> why the USSR tried to invade Finland and allocated a significant part of its entire military to the task while it was allegedly so worried about German attack

The USSR's invasion of Finland was intimately bound up with its fear of German invasion. I'm just reciting some basic history here - nothing new or groundbreaking. The USSR wanted a buffer outside of Leningrad, which was directly on the border, and the right to use naval bases in the Baltic sea. The Soviets did not believe that a small country would be able to remain neutral when push came to shove, so it did not trust Finnish promises of neutrality. Those were the considerations that led the USSR to invade Finland.