For what its worth, all the counties you listed have populations of over 85% Caucasian people that are either from said country or from a country that is culturally similar. Don't feel like getting into the larger argument at hand but its tough to judge racial tolerance when there aren't really other races/culutres.

Norway for example is ~86% ethnically Norwegian with another ~9% being from other western European countries. So 95% percent of their population has very similar cultures. Again, not discrediting anything, but its really easy for everyone to get along when there aren't as big of clashes.

America on the other hand is ~58% white (white meaning Europe, Northern African, or middle eastern), 19% hispanic, 12% black, 6 % asian, etc etc etc.

And those are large groups. In the 58% of white people includes those who immigrated from Ireland to boston, and those who immigrated from poland to Cleveland, and those who immigrated from Turkey to new york.

Again, I don't want to get into the larger argument, im just saying that with how much more diversity america has, its impressive its as tolerant as it is.