See, those were my arguments too. What I wasn't looking at is the difference between different sub-species of human. Humans are not fungible. Some humans are particularly malignant on average (bantu, central americans etc). I'd be fine with race based open borders, kinda, but even that can cause problems. East Asians, for instance, are low crime, high IQ, civilized humans, but commie-fake-china (Taiwan is the real China, and also NAM'BA WAN!!) is a hostile nation-state which has the first or second most prolific spy-network in the world. How to deal with that? From a solipsistic standpoint, open borders make sense. No one has the right to keep me out of any geographic area. But I'm a civilized human, and I'm not going to rape any native inhabitant, cut off any heads, steal from anyone etc.