[thrcanbonly1]

Fascism and it's cuddle buddy, Nazism(nationalist socialist worker's party), come from the spoutings of Antonio Gramsci, who said, in essence, that the people required to make socialism work were too smart to accept the idiocy of it all. So you have to trick them with nationalism and the trappings of nobility and/or an appeal to a (often made up)glorious past.
Nobody will sacrifice for the sake of some people on the other side of the world, (workers of the world, unite! remember that nonsense?)but they will sacrifice for their own perceived kind. That's how he proposed to get socialism going. Probably the most important thinker(in a bad way)of the last couple hundred years. Look at all the damage his followers have done. We are still repairing the damage they did for the last two terms.

[x]

Gramsci was a passionate opponent of fascism. Mussolini sent Gramsci to prison and he died under armed guard. Many of his writings weren't published until long after his death.

What you are discribing is the experience of many socialists in the years surrounding World War I. Mussolini himself, a socialist before the war, went through such an evolution. Gramsci and his other colleagues reviled him for putting nationalism above class-consciousness. Mussolini didn't need Gramsci to tell him what to do. Gramsci and others were commenting on what Mussolini was already doing and there was a rich Italian tradition of Machiavellianism for Mussolini to draw on.

Gramsci and Mussolini came out of a similar enviroment: early 20th century socialists and Marxists read Nietzsche, Bergson, Sorel, and other "new thinkers" and acquired, or at least encountered and explored, an interest in myth, the will and the irrational. Machiavelli also was widely read, analyzed and applied by intellectuals across the political spectrum. The national passions stirred by the war further influenced the thinking of the day. The conclusions drawn varied widely, though. Hitler was influenced by this mix, but at second hand. Later those who wrote about ideologies ignored the common soil of the era in which a variety of ideologies took seed.