Also known as America! You asked “how could veterans bring pizza back the US [sic] if somehow pizza was unknown in Italy.” To prove that, you quoted a section that showed veterans did not “bring pizza back” to America, it was already here. (Nobody claimed pizza “was unknown in Italy” prior to WWII, so I’ll ignore that part.)

WWII caused pizza to stop being seen as an immigrant food in America. It also caused the American pizza processes to intermix with those in Naples, both changing it into its modern form and helping it expand across the Italian peninsula.

I’ll note that you’ve misquoted once source, Wikipedia, complained you couldn’t access a second, and provided zero of your own all while rejecting evidenced culinary history. Curious to be proven wrong with sources versus stubbornness.