Interstate compacts are legal agreements between states that allow them to act collectively to address issues that transcend state borders. Interstate compacts that may affect the balance of power between states and encroach upon or impair the supremacy of the United States must have congressional consent. Since the late 1940s, states have entered into interstate compacts to facilitate the sharing of resources across state lines in response to disasters. In passing the Federal Civil Defense Act of 1950, Congress encouraged states to enter into interstate agreements that provided a legal framework for mutual defense aid and disaster assistance. By the early 1950s, virtually all states and other jurisdictions entered into defense aid and disaster compacts. However, after years of minimal financing and public support, the Federal Civil Defense Act did not play a significant role in facilitating disaster response. After Hurricane Andrew devastated southern Florida in 1992, Congress enacted many of the repealed provisions of the Federal Civil Defense Act into the Robert T. Stafford Disaster Relief and Emergency Assistance Act in 1994. Responding to similar concerns raised following Hurricane Andrew, the Southern Governors’ Association created the Southern Regional Emergency Management Assistance Compact to enable member states to provide mutual aid in managing any emergency or disaster that had been designated as such by the governor of the impacted state. It also provided for mutual emergency-related activities, testing, and training. In 1995, the Southern Governors’ Association opened membership to all U.S. states and territories, revising the terms of the agreement and adopting the new name, the Emergency Management Assistance Compact (EMAC). Congress consented to the compact in 1996. EMAC is a mutual aid agreement among member states and is not a government agency. Overall governance is provided by the EMAC Committee, whose chair is selected annually by the President of the National Emergency Management Association (NEMA). Day-to-day work of the EMAC Committee is carried out by an EMAC Executive Task Force whose members are elected by the EMAC membership. The Chair of the EMAC Committee works with the Executive Task Force to develop policies and issue guidance. NEMA provides administrative oversight for the EMAC network. Since 2003, NEMA has assigned one person to serve as the EMAC Coordinator—the only paid employee dedicated full time to EMAC—as well as a part-time consultant who serves in the position of EMAC Senior Advisor. Both of these positions have been funded through a cooperative agreement between FEMA and NEMA to provide administrative and management support for EMAC. EMAC operating protocols outline one process for member states to request and provide assistance, whether these resources are civilian or National Guard. The process describes how to request, provide, receive, and reimburse assistance from other member states in response to a disaster. Before resources can be deployed under EMAC, the governor of an impacted state must first declare an emergency. Representatives from the impacted state then contact EMAC leadership to inform them that interstate assistance may be needed. If desired, the impacted—or requesting—state can ask the EMAC leadership to send a team of emergency management personnel to the state’s emergency operations center to assist with subsequent resource requests under EMAC. The requesting state can then request additional resources through the EMAC network from other member states. These states—often referred to as assisting states—work with the requesting state to identify resources required and other details. Once both the requesting and assisting states approve the final details, resources are deployed to the area of need. Once the missions have been completed and resources have returned home, the assisting states prepare formal requests for reimbursement, which are then sent to, and processed by, the requesting state. Figure 1 provides a summary of this process. In cases when a disaster strikes multiple states, FEMA has a standing agreement with NEMA to request a team of emergency managers to deploy to its national or regional coordination centers to help coordinate EMAC network and federal activities, as appropriate. Although EMAC is an agreement between states, catastrophic disasters can overwhelm the resources of an impacted state, requiring it to seek assistance from the federal government. In the case of a presidentially declared disaster, impacted states can work with FEMA to seek federal financial assistance to cover costs associated with emergency response efforts that may include eligible missions conducted under EMAC. In such cases, the impacted state prepares project worksheets—a form used to collect and document information on the scope and estimated cost for public assistance projects—and submits them to FEMA for review. Once approved, FEMA will obligate funds for the project to the impacted state, which in turn reimburses the assisting state directly. As of June 2007, Mississippi and Louisiana are in the process of seeking financial assistance from FEMA to cover approximately $200 million for missions conducted under EMAC. The National Guard Bureau’s (NGB) mission is to participate with the Army and Air Force staffs in the formulation, development, and coordination of all programs, policies, concepts, and plans for the National Guard. NGB has visibility of all National Guard assets and advises the states on force availability to support all requirements. NGB serves as a coordinator between the Secretaries of the Army and Air Force and state National Guard assets. This is achieved through coordinating with state governors and adjutant generals. NGB also monitors and assists the states in the organization, maintenance, and operation of their National Guard units. Another aspect of NGB’s coordination is working with other DOD agencies as it carries out responsibilities to address domestic emergencies assigned in accordance with the National Response Plan (NRP). The purpose of the NRP is to establish a comprehensive, national, all-hazards approach to domestic incident management across a spectrum of activities, including prevention, preparedness, response, and recovery. In addition, it contains a catastrophic incident annex that establishes the strategy for implementing and coordinating an accelerated proactive national response to a catastrophic incident, including strategies to rapidly provide key resources to augment state, local, and tribal response efforts during a catastrophic event. The NRP also contains a catastrophic incident supplement with a detailed execution schedule that lists steps that agencies should take at specific times ranging from within 10 minutes of the start of an incident time to within 96 hours after the incident occurs. The purpose of this supplement is to accelerate the delivery of federal and federally accessible resources and capabilities in support of a response to a no-notice or short-notice catastrophic incident. These are incidents in which the response capabilities and resources of the local jurisdiction (including mutual aid from surrounding jurisdictions) will be profoundly insufficient and quickly overwhelmed. Since the inception of the EMAC in 1995, both the number of members and the volume and types of resources requested have grown considerably. States activated EMAC in response to a variety of emergencies, including hurricanes; floods; wildfires; and the September 11, 2001 terrorist attacks. In recent years, the volume and types of resources deployed under EMAC have also increased. Resources deployed under EMAC represented a substantial portion of overall out-of-state assistance deployed in response to the 2005 Gulf Coast hurricanes. EMAC membership has grown from a handful of members in 1995 to 52 today. EMAC grew out of the Southern Regional Emergency Management Assistance Compact, which was created in August 1993 by the Southern Governors’ Association and the Virginia Department of Emergency Services following Hurricane Andrew. When EMAC was formed in 1995, membership consisted of 4 states: Louisiana, Mississippi, Tennessee, and Virginia. Since that time, as figure 2 shows, EMAC membership has grown to 49 states, the U.S. Virgin Islands, Puerto Rico, and the District of Columbia. During this period, states have used EMAC in response to a variety of emergency events, including natural disasters, terrorist attacks, and other disasters and emergencies. For example, the states activated the EMAC process in response to disasters such as the 2005 Gulf Coast hurricanes; tornadoes in Kansas and Kentucky; floods in West Virginia and New Hampshire; wildfires in Texas and Nebraska; the September 11, 2001 terrorist attacks; and a variety of other disasters and emergencies, such as the 2003 Rhode Island Nightclub Fire and the Space Shuttle Columbia Disaster. In 2004 and 2005, the number and types of deployments under EMAC exceeded previous years’ deployments. Although deployment data for 1995 through 2004 are incomplete, EMAC leadership reported that deployments were higher in 2004 than in previous years. Data compiled by the EMAC network demonstrate that the total civilian and National Guard deployments in response to the 2005 Gulf Coast hurricanes were more than 25 times the number of the deployments for the 2004 Florida hurricanes. Figure 3 shows EMAC deployment data for some significant disasters. States have made larger requests for assistance under EMAC, and they have requested a wider range of resources. According to EMAC leadership, prior to 2004, states primarily requested emergency management personnel to support their state emergency operations centers. For example, of the estimated 40,000 people who responded to the September 11, 2001 terrorist attack on New York, New York officials requested only 26 emergency management personnel under EMAC to supplement state emergency management efforts. In 2004, Florida requested a wider variety of resources from other states under EMAC than had been requested in previous disasters. It requested first response personnel, health professionals, logistics support, and emergency management support for county emergency operations centers. In 2005, Louisiana, Mississippi, Texas, Alabama, and Florida requested an even greater variety of resources under EMAC, including 46,503 National Guard personnel, 6,882 law enforcement responders, 2,825 fire and hazardous materials responders, and 9,719 other responders, many of whom were local government assets deployed directly to the impacted areas. Figure 4 shows the variety of civilian personnel deployed under EMAC for selected significant disasters. Resources deployed under EMAC in response to the 2005 Gulf Coast hurricanes constituted a substantial portion of overall out-of-state response efforts. Following Hurricane Katrina in 2005, Louisiana and Mississippi both relied heavily on support from other states to supplement their own emergency response efforts.