The Spanish Civil War is actually slightly inaccurate. The Communist Party were sided with the Liberal Republicans instead of the revolutionaries - like the anarchists, and other socialists - and later prosecuted those revolutionaries and accused them of being fascists while a lot of them were still in the frontlines fighting actual fascists. The Communist Party were just serving the interests of the USSR, which at that point wanted a liberal government in Spain (due to their relation to France, if I recall correctly) and not a workers’ revolution.