Capitalists and communists in many countries helped cause their rise to power.

You're just saying that because "both sides" feels true to you. It's not, though. Communists in Germany were the bitterest opponents of the Nazis, before the latter even had a strong party formation. And as the first line of the poem goes, Communists were the first ones "they" came for (although this is usually omitted in liberal retellings".

If you've ever heard of Antonio Gramsci you know that imprisoning or killing communists was the first order of business under Mussolini.

You can name any country that went fascist, and we can point out where the capitalists were easing it along and the communists were fighting it tooth and nail.