According to Giovanni Gentile, the co-founder of fascism and Mussolini’s ghostwriter, fascism is “the most viable form of socialism.”
Mises wrote about “Russian socialism, “ i.e., Communism, and “German socialism,” i.e., fascism/Naziism. There are only small shades of difference. I often say that the difference between the two is roughly the difference between maroon and burgundy. Fascism is perhaps half a baby step to the right of Communism, but in practice, they amount to the same thing.
Fascist leaders like Mussolini and Hitler were admired by early progressives and they shared many ideas.
Fascism is simply a slightly different form of leftism than Communism is.
Fascism and Communism - Two rabid dogs fighting over the same bone.