International organizations (IOs) abound, ranging from the World Trade Organization, the European Union, and the United Nations. These institutions are forums for international cooperation and global problem solving, and they often have profound effects on the everyday interactions of states, with ultimate consequences for the lives of people worldwide. This course draws on theories of international institutions to explore IOs and address key debates, such as why states create IOs, how decisions in IOs are made, and what impact they have. It examines these questions across several issues, including peace and security, economic relations,  environmental politics, and human rights. IOs to be discussed include the United Nations, the World Bank, the World Trade Organization, the International Criminal Court and regional organisations like the European Union and the African Union.