"The National Prevention Framework describes what the whole community--from community members to senior leaders in government--should do upon the discovery of an imminent threat to the homeland. An imminent threat is intelligence or operational information that warns of a credible, specific, and impending terrorist threat or ongoing attack against the United States. This Framework helps achieve the National Preparedness Goal of a secure and resilient Nation that is optimally prepared to prevent an imminent terrorist attack within the United States.1 The processes and policies described in this document will be conducted in accordance with existing laws and regulations. This Framework provides guidance to individuals and communities, the private and nonprofit sectors, faith-based organizations, and all levels of government (local, regional/metropolitan, state, tribal, territorial, and Federal) to prevent, avoid, or stop a threatened or actual act of terrorism by  Describing the core capabilities needed to prevent an imminent act of terrorism;  Aligning key roles and responsibilities to deliver Prevention capabilities in time-sensitive situations;  Describing coordinating structures that enable all stakeholders to work together; and  Laying the foundation for further operational coordination and planning that will synchronize Prevention efforts within the whole community and across the Protection, Mitigation, Response, and Recovery mission areas."
Federal Emergency Management Administration: http://www.fema.gov/