Most contemporary theories of international cooperation treat states as unitary actors and, therefore, focus primarily on the functional benefits of cooperation or the collective action problems states confront in realizing it. 1 Less attention is paid to the impact of international negotiations and institutions on domestic politics, or to the consequences for international cooperation. This essay offers a theory of when and how international cooperation redistributes domestic power resources between state and society. Redistribution, it is argued, generally empowers national executives, permitting them to loosen domestic constraints imposed by legislatures, interest groups, and other societal actors. These shifts in domestic 'influence have important consequences for the nature of international cooperation. More specifically, I advance three arguments, each of which challenges existing understandings of international cooperation. First, international negotiations and institutions reallocate political resources by changing the domestic institutional. informational and ideological context in which domestic policy is made. Functional theories of international cooperation tend to assume that states are unitary actors, thereby overlooking that the domestic political benefits of cooperation are often distributed unevenly. Below I identify a typology, arguably comprehensive, consisting of four causal mechanisms by which international cooperation redistributes domestic political resources: shifting control over domestic agendas (initiative), altering decision-making procedures (institutions), magnifying informational asymmetries in their favor (information), and multiplying the potential domestic ideological justifications for policies (ideas). By examining these factors, we can predict whether cooperation will augment or undermine the power of domestic actors. Second, this reallocation of control over domestic political resources generally favors those who participate directly in international negotiations and institutions most often. though not invariably. national executives. National constitutions tend to grant executives special foreign-policy prerogatives. Diplomatic practices and international institutions, often established by agreement among executives, tend to recognize and reinforce these prerogatives. Where executives have primary access to international institutions, negotiations provide opportunities for national leaders to form "executive cartels," in which each colludes to strengthen the others' control over their own domestic instruments and increasing the cost of domestic opposition. The formation of "executive cartels" challenges the emphasis of existing "two-level" theory, which tends to stress the incentives for executives to "tie their hands," that is, to encourage tighter domestic constraints in order to increase international bargaining power. This analysis argues that executives are more concerned about domestic politics and therefore have an incentive to "cut slack," that is, to loosen binding domestic constraints. 2 This model demonstrates how executives can systematically exploit international negotiations and institutions to do so. Third, this shift in domestic rower resources toward executives feeds back into international bargaining. often facilitating international cooperation. Often the ability to "cut slack" provides an added incentive for national executives to seek international cooperation. Governments can exploit common gains from cooperation, because they are better able to circumvent opposition from particularistic interests. In extreme cases, executives may welcome multilateral restrictions on national sovereignty in place of unilateral action, even in the absence of a direct international quid pro quo, as long as it increases their autonomy at home-a paradoxical prediction for conventional theories of international relations.