Lenin and Stalin had killed millions before September of 1939. Estimates now sit at well over 20,000,000 people brutally murdered by Communists in Russia and Ukraine. With that being known why would England and France be so quick to declare war on Germany who at the start of the war in 1939 had committed no mass murder of any kind. Why did they side with Russia who also invaded Poland not just in 1939 but also in 1920?
Just after WWI communists had taken over all of Bavaria inside Germany and had to be removed by force. The same communist murderers who killed the czar and millions of other Russians tried to come through Poland to join the communists in Bavaria but the Polish people stopped them outside Warsaw. This showed the German people that communists from inside and outside Germany wanted their country and would commit the same atrocities on them.