I agree about the presence of the general resurgent right-wing movement and ideology in Italy and elsewhere post-9/11, but the term “alt-right” (apparently coined in Nov, 2008 – what a coincidence!) didn’t gain real widespread currency in the U.S. until late 2014. That, not co-incidentally, is when Gamergaters publically cemented the extreme right orientation of the misogynist and racist “manosphere.”
Before 2014 (but only by a few years) I knew these creeps more as “Neoreactionaries” and the “Dark Enlightenment” accelerationists associated with Land, Yarvin, and later Thiel. There were hints of sympathy to white nationalism with these types, but a full-blown open affiliation between with collection of hatemongers* didn’t emerge until after the MRAs and PUAs were drawn into what became the alt-right.
Personally, I saw the first stirrings of all this back in early 2001, when Ian Angell, an IT prof at LSE, talked about and seemed to embrace the concept of the “New Barbarians”. He was predicting elements of the brutal semi-feudal late-stage capitalist world we’re seeing now, gleefully embracing them, and advising readers on how to become winners (or “new barbarians”) in it.
Angell was approaching things from a techie Libertarian “free”-market extremist starting point, and a lot of people on the alt-right either take the same course or quickly come to integrate that philosophy into their thinking along with whatever racist and sexist and eliminationist hobbyhorses they ride.
[* e.g. fascists, neoNazis, KKKers, and other extreme-right thugs like the ones who almost killed you]