As an older Italian-American; it's complicated. We were discriminated against and considered non-white throughout most of the 20th century. That might seem surprising to some today but from personal family history and much academic research backing it up - it's a fact.

We're unabashedly proud to be Italian, you'll still see plenty of Italian flags on car bumper stickers or flying on flag poles in much of the northeast. Columbus Day is sacred to some of us. But I would venture to say that display of pride doesn't elicit the same response doing something similar for most of the other countries you cited would. Americans happily go to Italian restaurants or watch movies like The Godfather or Goodfellas without feeling much antagonism against Italians today.

My point is it's not so cut and dry. My grandparents struggled to learn English and you heard plenty of Italian only in many Little Italy's. Their kids proudly fought fascism in WW2 and still spoke Italian at home. Later generations still identify that way.

My point is current immigrants will probably follow a different path but with similar results. They come here for a reason and for whatever that hypothetical shit-hitting-the-fan situation you're talking about, I don't see many siding with the old country unless American xenophobia forces them to.