Camillo Berneri - Against the Racist Delirium « Robert Graham’s Anarchism Weblog
Berneri was an Italian anarchist and anti-fascist, and one of the first volunteers to fight on the side of liberty in the Spanish Civil War, before meeting his death, almost certainly at the hands of Soviet agents.
As Robert Graham mentions, Berneri stands alongside Rudolf Rocker in developing a critique of fascism and nationalism. I think Berneri's writings here stand out as way beyond his time. They stand up particularly strongly against both Marxist (including Trotskyist) analyses of fascism at the time, which could not get beyond its economic/class dimension. They also stand up well against the ultra-left position common within anarchism at that time (and today) that Nazism/fascism is merely an authoritarian variation on capitalist misrule, and thus not worth defending democracy from.