Military missions differ from nonmilitary missions on a variety of factors, as shown in table 1. Military missions involve coordinated military actions, such as campaigns, engagements, or strikes, by one or more of the services’ combat forces. Operations Desert Storm in 1991 and Iraqi Freedom in 2003 are examples of overseas military missions, and Operation Noble Eagle is a domestic military mission started on September 11, 2001, and continuing today. In the latter mission, the President directed the Commander, North American Aerospace Defense Command, to order combat air patrols to identify and intercept suspect aircraft operating in the United States. Since these are military missions, DOD is the lead federal agency and is prepared to apply its combat power if needed. Requests for nonmilitary missions are evaluated against criteria contained in DOD’s Directive, Military Assistance to Civil Authorities. These requests generally seek DOD support to help alleviate suffering, recover from disasters or assist indirectly with law enforcement. DOD’s directive specifies that requests for nonmilitary support be evaluated against the following criteria: legality (compliance with laws), lethality (potential use of lethal force by or against DOD forces), risk (safety of DOD forces), cost (who pays, impact on the DOD budget), appropriateness (whether the requested mission is in the interest of DOD to conduct), and readiness (impact on DOD’s ability to perform its primary mission). According to DOD, in fiscal years 2001 and 2002, it supported over 230 nonmilitary missions in a variety of settings, such as assisting in fighting wildfires, recovering from tropical storms, providing post-September 11, 2001, assistance to New York City and Virginia, providing support for the presidential inauguration, and for other purposes. According to DOD, during this same period, the Department rejected a handful of missions based on the above criteria. The 1878 Posse Comitatus Act prohibits the use of the Army and Air Force “to execute the laws” of the United States except where authorized by the Constitution or Acts of Congress. Federal courts have interpreted “to execute the laws” to mean the Posse Comitatus Act prohibits the use of federal military troops in an active role of direct civilian law enforcement. Direct involvement in law enforcement includes search, seizure, and arrest. The act does not apply to military operations at home or abroad. Further, it does not apply to National Guard personnel when under the direct command of states’ governors. Congress has expressly authorized the use of the military in certain situations. For example, DOD can use its personnel and equipment to: assist with drug interdiction and other law enforcement functions (10 U.S.C. §§371-378 (excluding §375)); protect civil rights or property, or suppress insurrection (the Civil Disturbance Statutes; 10 U.S.C. §§331-334); assist the U.S. Secret Service (18 U.S.C. §3056 Notes); protect nuclear materials and assist with solving crimes involving nuclear materials (18 U.S.C. §831); assist with terrorist incidents involving weapons of mass destruction (10 U.S.C. §382); and assist with the execution of quarantine and certain health laws (42 U.S.C. §§97-98). The President identified as a major homeland security initiative a review of the legal authority for military assistance in domestic security, which would include the Posse Comitatus Act. The President maintained that the “threat of catastrophic terrorism requires a thorough review of the laws permitting the military to act within the United States in order to determine whether domestic preparedness and response efforts would benefit from greater involvement of military personnel and, if so, how.” In addition to this review, the Congress directed DOD to review and report on the legal implications of members of the Armed Forces operating on United States territory and the potential legal impediments affecting DOD’s role in supporting homeland security. In March, 2003, the Commander of U.S. Northern Command has stated, “We believe the [Posse Comitatus] Act, as amended, provides the authority we need to do our job, and no modification is needed at this time.” At the time of our review, neither the President’s nor the congressionally directed legal reviews had been completed. It is too early to assess the adequacy of DOD’s new management organizations or its plans, although forces may not be fully tailored to the current domestic missions. DOD has established new organizations for domestic missions at the policy and operational levels, and written a new campaign plan for the defense of the United States. At the same time, DOD has used existing forces for these missions since September 11, 2001. However, at the time of our review, the organizations were not yet fully operational; plans had been developed before issuance of a counterterrorism threat assessment and before DOD officials had reached agreement on the nature of the threat; and force capabilities were not well matched to their domestic missions, potentially leading to an erosion of military readiness. Two new organizations—the Office of the Assistant Secretary of Defense for Homeland Defense and U.S. Northern Command—together provide long-term policy direction, planning, and execution capability but are not yet fully operational, because they have only recently been established and are not fully staffed. Because these organizations had only recently been activated and were still being staffed and structured, we did not evaluate the adequacy of these organizations for their missions. The Senate confirmed the President’s nominee to be Assistant Secretary of Defense for Homeland Defense in February 2003, but this office was not fully operational at the time of our review, with approximately one-third of the staff positions filled. The new Assistant Secretary is to provide overall supervision for domestic missions. U.S. Northern Command was established by the President in an April 2002 revision to the Unified Command Plan and was activated in October 2002. However, the command is not planned to be fully operational until October 2003. As of last week, only about 46 percent of the command’s positions had been filled. During our trip to U.S. Northern Command, we found that a key challenge that the command is grappling with is the need to conduct its ongoing missions while staffing the command’s positions. The activation of the command marks the first time that there has been a unity of command for military activities within the continental United States. Prior to U.S. Northern Command’s activation, U.S. Joint Forces Command provided for military actions to defend U.S. territory from land- and sea-based threats. The North American Aerospace Defense Command defended the United States from airborne threats (and still does). The Commander of U.S. Northern Command is also the Commander of the North American Aerospace Defense Command providing the new unity of command for the three missions. DOD’s planning process requires the Department and the services to staff, train, and equip forces for their military missions as outlined in campaign plans and deliberate plans developed by the combatant commanders, including the Commander of U.S. Northern Command. U.S. Northern Command’s campaign plan was completed in October 2002 and is classified. However, I can note, that although it may reflect current intelligence from DOD and other intelligence community sources, it was completed before the January 2003 issuance of the Federal Bureau of Investigation’s counterterrorism threat assessment, so it may not take all threats into account. Moreover, an official in the Office of the Secretary of Defense acknowledged that DOD officials continue to debate the nature of the threat to U.S. territory, thus DOD itself has not yet reached internal agreement on the nature of the threat facing the United States. Based on our review, DOD’s forces are not tailored for some of the missions that they have been performing since September 11, 2001, and the result could be eventual erosion of military readiness. To respond to the terrorist attacks of that day, the President identified the need to protect U.S. cities from air attack, and in response, DOD deployed 338 Air force and about 20 Navy aircraft within 24 hours of the attacks. Air Force fighter aircraft flew continuously from September 11, 2001, through March 2002, and intermittently thereafter. These combat patrols continue today. While these forces may obtain some training benefit from actually conducting the mission, the benefit is limited by the narrow scope of maneuvers performed during these missions. Specifically, Air Force and Air National Guard fighter units performing domestic combat air patrols are inhibited from executing the full range of difficult, tactical maneuvers with the frequency that the Air Force requires to prepare for their combat missions. In one Air National Guard wing that we reviewed, the average pilot could not meet their training requirements in 9 out of 13 months between September 2001 and September 2002. Consequently, such units may need to resume training after domestic combat air patrols end or they are reassigned, to ensure their readiness for combat operations, their primary missions. Similarly, DOD identified the need to enhance installation security, and it subsequently deployed active, reserve, and National Guard military police units for the mission. However, these units were designed for a different mission, and received limited training benefit from the domestic mission. For example, officials at a military police internment and resettlement battalion told us that while the battalion can provide installation security, its primary mission is to operate enemy prisoner of war camps. Instead, for nearly a year, the battalion carried out a domestic installation security mission, which while important, prevented the battalion from completing required training for its primary overseas combat mission. As a result, the battalion’s military readiness may become eroded, which could mean accepting an increased risk to the battalion if it deploys or resuming training before it deploys again. Current overseas and domestic missions are stressing U.S. forces as measured in personnel tempo data.