Societal conflicts are not only caused by ethnic and cultural differences, but by class conflict and struggle as well. Even the most homogeneous communities soon stratify themselves into economic castes and populations with conflicting interests. And of course, even the most xenophobic nations are always ready to go overseas as well as within their borders in search of resources, markets, labor and even slaves when some of those classes deem it in their interest. The history of the lily-white, Protestant, Anglophonic Americans, and their experience with Africans and European labor bears this out. Even the concept of "nationhood" wasn't completely specified until after the Civil War. Parallel developments also occurred in Spanish and Portuguese South America.

Contrary to nationalist fantasy, the nation-state is a relatively recent invention, dating back at most several hundred years. Prior to that, political structures generally encompassed many separate and unrelated ethnic groups, as they did in Rome, China, the Ottoman Empire and even Great Britain! Even modern Continental European countries are composed of traditional ethnic regions each with their own culture and language, usually now relegated to provincial status, when not suppressed entirely. Homogeneity is always imposed from the Metropole, it does not arise spontaneously in the hinterlands.

Left to themselves, people historically tend to form tribes based on kinship, not nations based on geography.