re: I assumed that.
What my insight, limited by lack of direct experience as it is, tells me is that Communism purports to be the dictatorship of the proletariat. Fascism is the dictatorship of the bourgeosie. Each uses the imagined threat of the other as the justification for its own tyranny, but the true cause lies in the greed and ambition of the tyrants. This is not a clash of ideas or philosophies, it is the toxic end result of careerism.