Hitler hated communists, and Russia was the main communist threat to Western Europe according to Hitler. They were included with the Jews, Slavs and other minorities that he hated.
Like everyone else that Hitler planned to destroy, he blamed communists for Germany's failure in World War 1, and the resulting crisis in the 1920s and 30s
Like everyone else that Hitler planned to destroy, he blamed communists for Germany's failure in World War 1, and the resulting crisis in the 1920s and 30s