What motivates states to follow international norms, rules, and commitments? All social systems must confront what we might call the problem of social control—that is, how to get actors to comply with society's rules—but the problem is particularly acute for international relations, because the international social system does not possess an overarching center of political power to enforce rules. Yet, taken in balance with other values, a measure of order is a valued good. Some take this absence of centralized power to mean that the international system is like a Hobbesian state of nature, where only material power matters; others see it as evidence that international rules have force only when they are in the self-interest of each state. I show that these two conclusions are premature because of their shallow reading of international society and misinterpretation of the ways in which authority works in domestic society.