The events of September 11th, 2001 altered the course of arms control intended to eliminate weapons of mass destruction (WMD) and made the role of international disarmament organizations controversial. Whether they can effectively verify compliance with the WMD treaty regime has been questioned by the United States. The study examines this by looking at the management of the three existing verification organizations--the International Atomic Energy Agency, the Comprehensive Test Ban Treaty Organization and the Organization for the Prohibition of Chemical Weapons--and draws conclusions for a future institution on biological weapons. It presents the IAEA verification system for nuclear weapons as a model for evaluating the systems for chemical and biological weapons. The importance of the IAEA's role has been recognized by the 2005 Nobel Peace Prize.