This dissertation brings "diplomacy" back into the international relations literature by proposing a theoretical framework to analyze the role that diplomacy plays in international disputes. Drawing front an extensive literature on the historical development of diplomatic institutions, I describe how diplomacy has evolved as a collection of institutional arrangements and instruments for conflict resolution. Through the course of (mostly European) history of international politics dating back to antiquity, diplomacy has served as an alternative to military might and warfare. Although diplomacy is one of the oldest institutions in international politics, it has not been the subject of rigorous theoretical or systematic empirical analysis. Its traditional absence from the international relations literature is primarily due to the difficulty in empirical observation in conjunction with the rise of behavioralism and the prevalence of strategic (or military) studies during the Cold War.
This dissertation offers a series of theoretical models that specify empirically identifiable mechanisms of diplomacy that tell us how to begin to ask empirical questions about how and why diplomacy works in international disputes. Specifically, through reconstructing a natural history of diplomacy, I offer a stylization of three basic machineries of diplomacy: (i) diplomatic communication that reveals states' preferences so that they can identify whether their preferences overlap in order to avoid war; (ii) diplomatic negotiation, by which states sort through their preferences to reach an agreeable settlement in order to avoid an imposed settlement via coercion and force; and (iii) diplomatic manipulation that restructures state leaders' preference so that they find it easier to acquiesce to a coerced settlement, and hence expands the range of agreeable settlements, thereby reducing the risk of war.
I develop the strategic logic of each of these mechanisms by analyzing a series of game-theoretic models that build on the rationalist literature on the origins of war and crisis bargaining. Over all, diplomacy works because it minimizes political costs associated with an attempt to bring peace and hence diffuses the risk of unwarranted wars. Diplomacy therefore is a system for conflict resolution without military force. I find that such a characterization of diplomacy is embedded in various aspects of its institution.
My Research