From the Chateau: People like to form into competing groups. This natural impulse is encoded in every human being’s DNA. It is a deeply embedded encoding, and can’t be excised. It can only be controlled by authoritarian measures, i.e. ultimately at the point of a gun. More 20th century borders is likely the manifestation of these ancient desires seeking to congeal into ever smaller, and thus more closely related, human tribes, and now being free to do so. It should be no surprise to a realist of human nature that more borders would lead to more war.
Naturally, the hopelessly naive among you might ask, “Why not just dissolve borders like we are doing here in the USA? Fewer borders should mean less war, right?” Incorrect. What instead will happen — and what we are seeing happening today in the USA — is a chaotic scramble — a BIOLOGICAL IMPERATIVE — to form de facto borders within the essentially borderless nation. (The modern USA is the closest approximation we have to an essentially borderless nation ruled by a legitimate government. There is no way to explain the unsupervised migration of 50 million Mexicans in 30 years that starts with the premise that we have a working border mechanism in place.)
De facto internal borders are based on race, ethnicity, religion, ideology, and social status, just as hard borders. La Raza is an internal border. The Congressional Black Caucus is an internal border. Journalism is an internal border (80-90% of journalists are registered Democrats). Cosmopolitan elites are an internal border. Schools are an internal border (ever notice how students congregate in a lunchroom cafeteria? How about the quickness with which urban white elites set off for the decidedly less diverse suburbs when the kids reach schooling age?). J-Date is an internal border. NASCAR is an internal border. Libertardian blogs are an internal border. Gay Pride and Puerto Rican Day parades are internal borders. Gerrymandered districts are internal borders. Neighborhoods are internal borders. Of course, one notable group has no recognized internal border at all. And we know what happens to undefended, borderless lands: they get overrun.