Legitimacy and authority in international politics

The idea that the legitimacy of international institutions affects state behavior is increasingly common in discussions of international relations, and yet little has been said about what the term legitimacy means or how it works. This is peculiar, since legitimacy is widely cited in domestic social studies as a major reason, along with coercion and self-interest, that actors obey rules. I examine the concept of legitimacy, defined as the internalization of an external rule, as it is used in domestic studies and in international relations, and find that the existence of institutions that states accept as legitimate has important implications for theories of international relations. Using the norms of sovereign nonintervention as an illustration, I compare coercion, self-interest, and legitimacy as three motivations for rule-following by states. Self-interest and coercion, alone or together, are insufficient to sustain the pattern of behavior we recognize as the system of sovereign states. The degree of settledness of borders, especially among states of unequal power, indicates that the institution of sovereignty owes part of its persistence to the widespread acceptance by states of the norms of sovereignty as legitimate. This is important for international relations because the existence of legitimate rules signals the presence of authority, which is inconsistent with the received image of the international system as anarchic. I conclude the article by charting a course of further research into the ideas of legitimacy, authority, and anarchy.