Post-Cold War world divides people primarily by culture, not ideology or economics.

Evidence

In the late 1980s the communist world collapsed, and the Cold War international system became history. In the post-Cold War world, the most important distinctions among peoples are not ideological, political, or economic. They are cultural. Peoples and nations are attempting to answer the most basic question humans can face: Who are we? And they are answering that question in the traditional way human beings have answered it, by reference to the things that mean most to them. People define themselves in terms of ancestry, religion, language, history, values, customs, and institutions. They identify with cultural groups: tribes, ethnic groups, religious communities, nations, and, at the broadest level, civilizations. People use politics not just to advance their interests but also to define their identity. We know who we are only when we know who we are not and often only when we know whom we are against. — Samuel P. Huntington, The Clash of Civilizations and the…, 41

Categorization

• XREF: The identity-through-opposition thesis recalls the us/them construction common to nationalism studies and the tribalism literature, and echoes the reader’s prior filing on communication technology shaping community identity.
• SEED: An essay angle: ‘We know who we are by whom we are against’ as the engine of modern political polarization across both identity politics and civilizational discourse.