XXth century fascism was the west's capitalists reaction to communists taking power all around them. Rich assholes started financing rabid anti-communists to kill leftists.

An early version of fascism is described in Marx's 18th Brumaire, in which he describes a failed revolution being followed by a period of terror, when anyone the cops thought was involved with workers movement could be killed in the street.

From the end of WWII to now, imperialists have been financing far-right groups to counter communists/leftist/progressive groups wherever they seem to be getting some power. See operations Gladio and Condor, and also the Jakarta Method