> The whole concept of nationalism and border sovereignty has been with us for essentially all of human history,

Quite the opposite. The modern concept of "border sovereignty" as intertwined with the nation-state is a Westphalian construction. (Students of world history will recognize why this timing is not a coincidence). And even then, they didn't exactly catch on immediately.

Sovereign nation-states are a tiny piece of human history. They're not even the majority of recorded human history.

What, your ancestors between 600k years ago up to 150 years ago are a joke to you? Human history began with European Great Powers?

Göbekli tepe easily refutes your isolationism, as does stone- and bronze-age globalism.

That's partially true; the bit about borders and human history (so long as you sequester 'history' to 'recorded history') - but nationalism is actually newer than you'd think, and there were human societies for thousands of years before there were borders. More recent if you go by the current definition of border (formalized, surveyed borders are also relatively modern).

Is nationalism going to peter out? No, of course not. Do some people care for reasons that are important to them? Sure, I don't want to tell anyone how to feel. I am just another jerk with an opinion like the rest of us.

But if you were to ask me, it's take it or leave it. I'd be more than happy to see free movement in the world. Just another set of rules I'm not using.

It's not just a human thing; people who study wolves find they maintain surprisingly strict borders between different packs, and this behavior continues though a lot of other mammals and even some smaller animals like certain birds and insects.

What are those reasons?

The US (where “open borders” are often characterized as national “suicide” by right-wing figures) had open borders well within living memory.

By ship? No. But you’re from Argentina and made it all the way up to the Rio and want to cross to work on US farms or whatever? Yeah whatever man, totally fine, just walk in. Anyone from the Americas was welcome, no waiting, no la migra hunting them, no nothin’

We didn’t change that until the ‘60s, and the only reason it didn’t cause a ton of problems immediately (farms at that time were already heavily dependent on migrant labor operating a bit under the table, and their lobbies were not quiet on the issue) was that enforcement was and has been, at times (and especially at first) mostly rather half-assed.

[dead]

[dead]