This popular text for courses on international organizations and international relations provides a comprehensive yet accessible introduction to the United Nations, exploring the historical, institutional, and theoretical foundations of the UN as well as the political processes and issues facing the organization today. Thoroughly revised throughout, the fourth edition focuses on major events since 2006, including the influence of emerging powers such as China, India, and Brazil, the crisis in UN peacekeeping, and the continuing decline of the UN's relevance in international economic relations. This edition also includes a new chapter on the future of the United Nations, as well as new case studies on peacekeeping in the Democratic Republic of Congo, human trafficking, and the challenges of state building for human security in Haiti. Helpful student resources include the Charter of the United Nations, a list of acronyms, discussion questions, suggested resources for additional research and reading, and a glossary.