Introduction : "Two worlds" of international security / Bruce D. Jones and Shepard Forman -- "The mission determines the coalition" : the United States and multilateral cooperation after 9/11 / Stewart Patrick -- UN transformation in an era of soft balancing / Stephen John Stedman -- An evolving UN Security Council / David M. Malone -- Too many institutions? European security cooperation after the Cold War / Richard Gowan and Sara Batmanglich -- Whither NATO / Mats Berdal and David Ucko -- The evolution of nuclear nonproliferation institutions / Christine Wing -- 9/11, the War on Terror, and the evolution of multilateral institutions / Eric Rosand and Sebastian von Einsiedel -- Evolution and innovation : biological and chemical weapons / Fiona Simpson -- Normative evolution at the UN : impact on operational activities / Ian Johnstone -- Constructing sovereignty for security / Barnett R. Rubin -- New arrangements for peace negotiation / Teresa Whitfield -- International humanitarian cooperation : aiding war's victims in a shifting strategic environment / Abby Stoddard -- The evolution of regional and subregional collective security mechanisms in post-Cold War Africa / A. Sarjoh Bah -- International courts and tribunals / Cesare P.R. Romano -- Conclusion : international institutions and the problems of adaptation / Richard Gowan and Bruce D. Jones.