Hot take: I think immigration and multiculturalism is going to be the the biggest and the defining issue of this century. The history books will have "AI" and climate change in the margins as 'exacerbating factors'. We've started to see it in the US, and we're beginning to see the start to it in the EU. Japan--rightly or wrongly--might be averting a future disaster here. Japan is lucky in that they are still a very homogeneous society, and also unlucky in that they are ahead of the curve in population decline. I think the western world is in for a bad time over the next 50 years.