DOMESTIC POLITICS AND INTERNATIONAL COOPERATION: A SIGNALING MODEL*

Over the past five decades, extensive cooperation has persisted among the industrial countries. Most theories of international politics can only partially, if at all, explain this. Their weakness is that states are treated as unitary actors, and domestic politics is ignored. A general theory of the conditions under which states will cooperate requires consideration of domestic politics. Our goal is to present a formal model revealing how domestic politics affects international cooperation. Our model examines the interaction between international negotiations and domestic politics. It focuses on the structure of domestic actors' preferences, the beliefs of political actors, and the degree of internal divisions as explanatory factors. We try to systematize the counterintuitive argument that more domestic divisions may increase the president's or prime minister's international bargaining capabilities. Generally, we demonstrate how domestic divisions affect international negotiations; in particular, we examine the effects of "divided government" on the substance of international agreements. We also seek to illuminate the extent of autonomy of the executive in foreign negotiations, given the constraints of the domestic political system. We show, first, in many cases international agreement is less likely when domestic actors are more divided. Second, the degree of autonomy available to the executive depends on the beliefs of the legislature about the nature of the international agreement negotiated by the executive and the structure of domestic preferences. In many cases, the conventional wisdom that increases in the divisions among domestic actors augment the degree of executive autonomy does not hold. The degree of executive autonomy is a function of the type of cleavages in domestic politics, not just in their magnitude