Two interesting points I'd like to raise: 1) Up to 1941 European communists were in a difficult position because the Soviet Union was allied to Hitler. pearl Harbor changed this and communist Resistants (Spanish and French in France) , Greeks, Poles etc.... became much more active when they no longer had political issues. 2) The Rotfront Partei in Germany was Hitler's enemy : their members are were massively deported and sent to DACHAU years before the war started. They are forgotten Resistants. Accusing the Communinsts of bunring the Reichstag comforted Hitler's might. The fear of the 1918 Revolution and Rosa Luxemburg brought many votes to the Nazis.