This is the only solution, ultimately. These immigration/multicultural policies are not simply misguided, they're a declaration of war of the native people of these nations. So long as the governments stand, the problem will persist.
Maybe the only reason the US "isn't there" is because we have guns. Hear me out. There's a big chasm between kicking someone's ass and mowing people down. There's a tether back from the former, but there's no nonviolent way to walk back the latter. Once you go there, you basically commit to war and have to see it through to the end.
That, and our population is so spread out.