“This directive [HSPD 21] establishes a National Strategy for Public Health and Medical Preparedness (Strategy), which builds upon principles set forth in Biodefense for the 21st Century (April 2004) and will transform our national approach to protecting the health of the American people against all disasters…. (5) This Strategy draws key principles from the National Strategy for Homeland Security (October 2007), the National Strategy to Combat Weapons of Mass Destruction (December 2002), and Biodefense for the 21st Century (April 2004) that can be generally applied to public health and medical preparedness. Those key principles are the following: (1) preparedness for all potential catastrophic health events; (2) vertical and horizontal coordination across levels of government, jurisdictions, and disciplines; (3) a regional approach to health preparedness; (4) engagement of the private sector, academia, and other nongovernmental entities in preparedness and response efforts; and (5) the important roles of individuals, families, and communities. (6) Present public health and medical preparedness plans incorporate the concept of “surging” existing medical and public health capabilities in response to an event that threatens a large number of lives. The assumption that conventional public health and medical systems can function effectively in catastrophic health events has, however, proved to be incorrect in realworld situations. Therefore, it is necessary to transform the national approach to health care in the context of a catastrophic health event in order to enable U.S. public health and medical systems to respond effectively to a broad range of incidents. (7) The most effective complex service delivery systems result from rigorous end-to-end system design. A critical and formal process by which the functions of public health and medical preparedness and response are designed to integrate all vertical (through all levels of government) and horizontal (across all sectors in communities) components can achieve a much greater capability than we currently have. (8) The United States has tremendous resources in both public and private sectors that could be used to prepare for and respond to a catastrophic health event. To exploit those resources fully, they must be organized in a rationally designed system that is incorporated into pre-event planning, deployed in a coordinated manner in response to an event, and guided by a constant and timely flow of relevant information during an event. This Strategy establishes principles and objectives to improve our ability to respond comprehensively to catastrophic health events. It also identifies critical antecedent components of this capability and directs the development of an implementation plan that will delineate further specific actions and guide the process to fruition”. (White House, Homeland Security Presidential Directive (HSPD-21), Subject: Public Health and Medical Preparedness, October 18, 2007).