Can international institutions affect state behavior, and if so, how? This question has motivated decades of research that has substantially deepened our understanding of how international processes affect states. This dissertation contributes to this body of research by focusing on global cooperation in environmental politics and human rights. This type of cooperation poses complex challenges because negotiators face incentives to water down treaty commitments in order to enhance participation and strategies for enforcing obligations are limited. I argue that the ability of these institutions to affect state behavior by encouraging domestic pressure for fulfillment of states' international commitments makes certain types of institutions more likely to deliver intended effects on state behavior. I also suggest, however, that this mechanism may be in danger because of growing restrictions on non-governmental organizations (NGOs) whose work is critical to the mobilization process. Therefore, this dissertation contributes new insight into the link between international institutions, domestic political dynamics, and state behavior, and offers policy recommendations for enhancing the impact of such institutions.