Social fascism was a theory developed by the Communist International (Comintern) in the early 1930s which saw social democracy as a moderate variant of fascism.

Fascism is a far-right, authoritarian, ultranationalist political ideology and movement, characterized by a dictatorial leader, centralized autocracy, militarism, forcible suppression of opposition, belief in a natural social hierarchy, subordination of individual interests for the perceived good of the nation and/or race, and strong regimentation of society and the economy.