What isn't dead is the potential for violent conflicts based on ethnicity. I suspect one of the reasons why so many Americans don't see any downside to multicu

What isn't dead is the potential for violent conflicts based on ethnicity. I suspect one of the reasons why so many Americans don't see any downside to multiculturalism is that the American military and law enforcement are so strong that the very concept of an alienated ethnic minority threatening stability or existence of the entire country is ludicrous. Most other countries in the world are weaker. Hitler used the pretext of "protecting ethnic Germans" to invade several places, and so does now Putin. In the Russian propaganda since 2014, the theme of "protecting Russian speakers against Ukrainian oppression" is pretty central. Needless to say, European countries are now fairly wary about their own Russian minorities, the Baltic states most of all. (It does not help that Russians were shipped there by Stalin in the thousands precisely to sway demographics.) As I said, the US may be immune to this kind of threat, but Japan is in a different situation. For example, looking at the development in China, Tokio would be absolutely rational to be wary of large-scale immigration from there.