John T. Flynn's 1944 book As We Go Marching is one of those libertarian classics that gets cited much more frequently than it gets read. Hopefully it will attract a few more readers now that the full text is online.
I don't agree with everything in the book, but it's a stimulating, contrarian analysis of the origins of fascism—in Italy, in Germany, and, Flynn feared, in the United States. For Flynn, the movement emerged
from among those erstwhile socialists who, wearying of the struggle, have turned first to syndicalism and then to being the saviors of capitalism, by adapting the devices of socialism and syndicalism to the capitalist state. The industrialists and nationalists joined up only when the fascist squadrons had produced that disorder and confusion in which they found themselves lost. Then they supposed they perceived dimly at first and then more clearly, in the preachments of the fascists, the germs of an economic corporativism that they could control, or they saw in the fascist squadrons the only effective enemy for the time being against communism.
Somewhere in the boxes behind my desk, there's a paper I wrote as an undergraduate comparing the treatment of fascism in As We Go Marching and in Philip K. Dick's The Man in the High Castle. I'd dig out an excerpt from that too, but I have my pride.