Ideas and concepts have been a driving force in human progress, and they may be the most important legacy of the United Nations. UN ideas have set past, present, and future international agendas in many global economic and social arenas and have also led to initiatives and actions that have improved the quality of human life. This capstone volume draws upon findings of the other 14 books in the acclaimed United Nations Intellectual History Project Series. The authors not only assess the development and implementation of UN ideas regarding sustainable economic development and human security, but also apply lessons learned to suggest ways in which the United Nations can play a fuller role in confronting the challenges of human survival with dignity in the 21st century.