In Chicago at least you can find people from everywhere coexisting, I hear people talking in Russian, Polish, Vietnamese, Korean, Chinese, Japanese, Portuguese, Spanish, Italian, German, etc.. just by walking the isles of Costco.
The funny thing is that in Japan there is no diversification and they look down to other races around their area and let's not start how they look down to women. And how do they feel about the Chinese?.
As for Europe, well there are still rivalries even inside countries, the Germans always looked down to the Spanish workers that emigrated there many decades ago. The French same thing with the Swiss, they even jokingly call them Le petite suisse like in the name of the cheese. Italians don't mix well with Sicilians, etc,etc,etc.. And don't even try to explain the futbol fanaticism, it's out of control and pushes the hatred more so.
The US even if not perfect, is way ahead in diversity than any other place in the planet.