The network of public agencies, private firms, nonprofit organizations, ad hoc groups, and individual volunteers that deals with natural and technological hazards and disasters did a remarkable job of responding to and helping us recover from the September 11th attacks. That national emergency management network, along with the national security and law enforcement networks, provides a foundation for our war on terrorism, helps us mitigate the hazard of terrorism, and improves our preparedness for future violence. However, coordinating the efforts of the networks will be a real challenge for the director of homeland security and his or her state and local counterparts. Coordination will necessitate using legal authority to assure compliance, economic and other incentives to encourage compliance, formal partnerships to encourage collaboration, informal understandings to encourage cooperation, and personal encouragement to influence appropriate action. A top–down, command–and–control approach to the war on terrorism, such as the proposed Department of Homeland Security is intended to provide, may be counterproductive.