The World Health Assembly adopted the new International Health Regulations on May 23, 2005. The new IHR represent the culmination of a decade-long revision process and an historic development for international law and public health. The new IHR appear at a moment when public health, security, and democracy have become intertwined, addressed at the highest levels of government. The United Nations Secretary-General Kofi Annan, for example, identified IHR revision as a priority for moving humanity toward “larger freedom.” This article analyzes (...) the new IHR and their implications for global health and security in the 21st century.The WHA instructed the WHO Director-General to revise the IHR in 1995 because the Regulations did not provide an effective framework for addressing the international spread of disease. Doubts about the IHR's effectiveness had, however, been present long before 1995. The critiques identified the narrow scope of the regulations, the lack of compliance by states, and the absence of a strategy for responding to rapid changes in public health's global economic and technological environments. (shrink)