Provides a framework for analyzing emergency-response performance requirements in the aftermath of a major terrorist attack. Since the terrorist attacks of 2001, emergency responders and decision makers have intensified their efforts to implement steps for improving the nation's ability to respond to large terrorist attacks. Such efforts have been hampered, however, by uncertainty over how the emergency response community should prepare for such attacks. This monograph presents a framework for characterizing what emergency responders must be prepared to do after a terrorist attack. It provides a way to quantify emergency-response performance requirements in terms of life-saving missions.