Earlier quoted context omitted.
For a migratory species it is literally inhuman to erect a border. Borders should be jurisdictional boundaries but should be permeable like the states in the US. The rest of the tribalism BS is just that.
Humans stopped being migratory about 12,000 years ago. You probably don't want criminals to freely move into your country. You probably want a country that gets funded by taxes (both short term and long term). No country in the world maintains open borders. Everytime there has been mass unorganized migration it has been a humanitarian disaster. Platitudes only work on paper.
Are all of these unorganized, mass migrations disasters? Or are they in response to disasters?
Most organized mass migrations have been disasters. Forced relocations aren’t fun.
But unorganized mass migrations, where people say “let’s get out of this place and go somewhere better” tend to mitigate pre-existing disasters.