Fully revised and updated, this popular and broad-ranging textbook provides a systematic introduction to the structure, policies and performance of international organizations. Despite being a relatively new phenomenon, international organizations are involved in innumerable issue areas. This core text analyses IOs at the regional and global levels to show how institutions such as the UN, OECD, AU, EU and many others contribute to contemporary global governance and the norms and rules which guide transnational responses to problems such as climate change, weapons of mass destruction and global terrorism.