Introduction: "Two worlds" of international security. -- "The mission determines the coalition": the United States and multilateral cooperation after 9/11. -- UN transformation in an era of soft balancing. -- An evolving UN security council. -- Too many institutions? European security cooperation after the Cold War. -- Whiter NATO. -- The evolution of nuclear nonprolifferation institutions. -- 9/11, the war on terror, and the evolution of multilateral institutions. -- Evolution and innovation: biological and chemical weapons. -- Normative evolution at the UN: impact on operational activities. -- Constructing sovereignty for security. -- New arrangements for peace negotiation. -- International humanitarian cooperation: aiding war's victims in a shifting strategic environment. -- The evolution of regional and subregional collective security mechanisms in post-Cold War Africa. -- International courts and tribunals. -- Conclusion: international institutions and the problems of adaptation.

1. International courts
2. Humanitarian law -- International cooperation
3. Humanitarian assistance -- United States
4. Terrorism -- Prevention
5. Nuclear nonproliferation
6. Security
7. International -- Governemnt policy -- United States
8. Peace-building
9. Security
10. International