What makes military threats effective? How do states choose partners when forming alliances and trade pacts? Why do some states gain more in international negotiations? These are some of the many questions that IR scholars have answered using domestic-level theories. This course introduces students to the most prominent theoretical mechanisms developed in this research program and the empirical evidence used to evaluate them. The topics to be covered are in both international security and cooperation. The goal is that at the end of the course students will have a framework of the main domestic actors and their influence on foreign policy.