The American ideal is now a civic society that's not predicated on the idea of having a "people" who the nation-state is created for. Citizens still often think that they have a "people", but that delineation does not extend to all Americans. As an example a second-gen Mexican person is not particularly likely to consider me part of their "clan" even though we are both American. When everyone's foreign, no one is.
Not been my experience in NYC and other places. Quite the opposite. Also have you seen European integration of foreigners up close? Middle East? Asia?
My guess is no, because these places make it far more difficult to assimilate (if not impossible)
I suspect we're disagreeing over what it means to "assimilate" or "be accepted as" one of an ethnic group. Imagine a stirring speech where a speaker says "I have dreamed of a respite from the trials our people have undergone". When the audience hears "our people", they are going to think of a certain group that they imagine themselves belonging to. In America, a miniscule fraction of the population thinks of "everyone who is legally an American" when they hear the phrase "our people".
However, some other place like Paris, the massive city-state of the white Franks, has a carefully guarded culture that they gatekeep as a majority ethnic group. You can live in France, and you can speak French, but you can't "become French" because many of the people who call themselves "French" think specifically of white Frankish/Gaulish/Roman descendents. That's just not happening in major American cities.
So, ghettos. I'm not saying there's not a "little Italy" in most American cities, but a Turkish person living in Germany their whole life is still Turkish. American in Japan, same. These places don't even allow the possibility of assimilation.
Or as my English friend put it, "there's a difference between tolerance and acceptance."
> A big part of American fear is knowing that nearly every single person you interact with that isn't a friend of yours doesn't really consider you their "people".
The other side of this coin: America actually accepts people from other places. Most of the world will always see you as foreign if you come from abroad, even if you have lived there your whole life.