Are many contemporary international theories, mostly derived implicitly or explicitly from the European, Westphalian experience of identical units – nation-states – interacting under anarchy, both universal and inevitable? The world is wider, and older, than many of the ideas embedded in most contemporary international relations theory assume it is. Did that older world act the same way across time and space as does the contemporary, European-derived order? Or, do different international systems have different fundamental organizing principles, which produce distinct patterns of cooperation and conflict?