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.

Isn't that the story of the US since birth? It seems immigration is just always a hot topic, everyone always thinks they can just pull up the latter behind them as to not lose what they have to others. I don't feel anything is different now.

I don’t this can even be debated. Immigration is the number one discussed issue in rich countries and immigration policy is causing massive swings in elections.

What disaster is Japan averting?

There are Ceuta like events of a smaller scale every day at every border of western europe. Dont need to wait 50 years. Not a single european voted for this. French people also voted no to a european economy but those who seized power didnt care