Every 4 years, as part of the Quadrennial Defense Review, DOD conducts a comprehensive examination of the national defense strategy, force structure, force modernization plans, infrastructure, budget plan, and other elements of the defense program, and establishes a defense program for the next 20 years. This process helps ensure that DOD can effectively support the broader national security strategy of the United States. The 2001Quadrennial Defense Review Report was issued shortly after the September 11, 2001, terrorist attacks and outlines a new defense strategy to (1) assure allies and friends that the United States can fulfill its commitments, (2) dissuade adversaries from undertaking activities that threaten U.S. or allied interests, (3) deter aggression and coercion, and (4) decisively defeat any adversary, if deterrence fails. Operation Noble Eagle was an immediate response to the September 11, 2001, terrorist attacks; is intended to directly defend the homeland; and is ongoing. Operation Noble Eagle missions include combat air patrols over major American cities and enhanced security at federal installations. A combat air patrol is an airborne air defense activity involving fighter aircraft patrolling a given area. To support fighter coverage, other military activities have included aerial refueling and airborne early warning; comprehensive radio and radar coverage of the patrolled area; and command and control centers to direct fighter pilots when a threatening aircraft is detected. Concerns about terrorist threats to federal installations increased following the 9-11 attacks; therefore, DOD enhanced installation security to harden facilities against attacks and deter future attacks through the deployment of additional personnel (such as military police). In April 2002, the President approved a revision to DOD’s Unified Command Plan, creating the new U.S. Northern Command. U.S. Northern Command was activated on October 1, 2002, and is scheduled to be fully operational on October 1, 2003. Its area of responsibility includes the continental United States, Alaska, Canada, Mexico, and the surrounding waters out to approximately 500 nautical miles, which includes Cuba, the Bahamas, British Virgin Islands, and Turks and Caicos. Figure 1 displays U.S. Northern Command’s area of responsibility as indicated by the darkened boundary line. U.S. Northern Command is responsible for the air, land, and maritime defense of the continental United States. Its mission is to conduct operations to deter, prevent, and defeat threats and aggression aimed at the United States, its territories and interests within assigned areas of responsibility, and as directed by the President or Secretary of Defense, provide military assistance to U.S. civil authorities, including consequence management operations. In June 2002, the President proposed creation of the Department of Homeland Security and in November 2002, Congress approved legislation consolidating 22 federal agencies within the new department. In July 2002, the administration published the National Strategy for Homeland Security, which defines homeland security as a “concerted national effort to prevent terrorist attacks within the United States, reduce America’s vulnerability to terrorism, and minimize the damage and recover from attacks that do occur.” The National Strategy for Homeland Security broadly defines DOD’s contributions to national homeland security efforts to include the prosecution of military missions abroad that reduce the terrorist threat to the United States; military missions conducted within the United States that DOD conducts under extraordinary circumstances with support, as needed, by other agencies; and support to U.S. civil authorities under emergency circumstances, where DOD is asked to act quickly and provide capabilities that other agencies do not have or for limited scope missions where other agencies have the lead. In August 2002, DOD proposed the creation of a new Office of the Assistant Secretary of Defense for Homeland Defense. Congress approved it with passage of the Bob Stump National Defense Authorization Act for Fiscal Year 2003. The new office establishes a senior civilian officer within the Office of the Secretary of Defense with a principal focus on the supervision of the homeland defense activities of DOD (i.e., the assistant secretary supervises the execution of domestic military missions and military support to U.S. civil authorities and develops policies, conducts analyses, provides advice, and makes recommendations for these activities as well as emergency preparedness and domestic crisis management matters to the Under Secretary for Policy and the Secretary of Defense). The assistant secretary also supports the development of policy direction to the Commander of U.S. Northern Command and guides the development and execution of U.S. Northern Command plans and activities. The Assistant Secretary of Defense for Homeland Defense is also responsible for representing DOD when interacting with federal, state, and local government entities. In September 2002, the President released The National Security Strategy of the United States of America. The strategy identifies U.S. interests, goals, and objectives vital to U.S. national security; and explains how the United States uses its political, economic, military, and other elements of national power to protect or promote the interests and achieve the goals and objectives identified above. Military and nonmilitary missions differ in terms of roles, duration, acceptance, and capabilities normally employed. Generally, military missions are those primary warfighting functions that DOD performs in defense of the nation and at the direction of the President functioning as the Commander-in-Chief. Conversely, in nonmilitary missions, DOD provides military capabilities in support of U.S. civil authorities as directed by the President or Secretary of Defense. Table 1 provides more details on the key differences. Military missions involve warfighting functions, 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 ongoing today. In the latter mission, the President directed the Commander, North American Aerospace Defense Command (NORAD), to order combat air patrols to identify and intercept suspect aircraft operating in the United States. Because this is a military mission, DOD is the lead federal agency and is prepared to apply its combat power, if needed. Requests for nonmilitary missions generally seek DOD support to help after the impact of natural or man-made disasters, or assist indirectly with law enforcement. These requests are evaluated against criteria contained in DOD’s Directive, Military Assistance to Civil Authorities. 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 it is in the interest of DOD to conduct the requested mission), 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 support for national security special events (such as the presidential inauguration and 2002 Olympic Games), and for other purposes. According to DOD, during this same period, it rejected several missions based on the above criteria. For example, in November 2001, DOD declined a request from the U.S. Capitol Police to provide military medical personnel; however, DOD did not indicate which criteria were used to reach this decision. Since September 11, 2001, the threat of another catastrophic terrorist event has altered some military operations. Before September 11, 2001, DOD generally emphasized deterring and defeating adversaries through overseas power projection, and still does. Since then, DOD has deployed U.S. forces overseas to prosecute the war on terrorism in Afghanistan and elsewhere. Moreover, The National Security Strategy of the United States of America, published after September 11, 2001, emphasizes preventing terrorist attacks against the United States. The strategy states that the immediate focus of the United States will be those terrorist groups having a global reach and any terrorist or nation that sponsors terrorism which attempts to gain or use weapons of mass destruction. Such threats may now be subject to a preemptive strike by U.S. military forces if necessary, to prevent these threats from materializing or reaching the United States. Some operations associated with domestic military missions have also changed to proactively respond to terrorist threats. Prior to September 11, 2001, DOD’s strategy defended air, land, and sea approaches to U.S. territory from military adversaries presumed to originate outside the United States. If necessary, DOD had planned to deploy U.S. military forces within the United States to counter the military threats. DOD still plans to do so should these threats emerge in the future. However, the current defense strategy, published in the 2001 Quadrennial Defense Review Report, states that the highest priority of the U.S. military is to defend the homeland from attack by any enemy, which includes terrorists. An example of how domestic military operations have changed to meet terrorists’ threats can be seen in NORAD operations. Before September 11, 2001, NORAD primarily focused its attention on aircraft approaching U.S. airspace and acted to prevent a hostile aircraft from entering U.S. airspace. Since then, NORAD has expanded its focus so that it now also monitors aircraft operating within the United States as well as aircraft approaching U.S. airspace. Also, before September 11, 2001, NORAD had planned to order Air Force units to intercept military adversaries’ bombers. NORAD still plans to do so if these threats emerge in the future. However, as of September 11, 2001, NORAD also orders combat air patrols over U.S. cities to prevent terrorist attacks. In another example, before the attacks of 9-11, many federal installations operated at a normal force protection condition or routine security posture that allowed for open access to the installations, in many cases. However, since then, DOD has used additional military personnel to enhance security by verifying identification of all personnel and vehicles entering the installation and conducting patrols of critical infrastructure on the installation. Also, in April 2002, the President approved a revision to DOD’s Unified Command Plan, creating the new U.S. Northern Command, which has responsibility to militarily defend the continental United States and other nearby areas. Moreover, DOD continues to support U.S. civil authorities for nonmilitary missions as it did prior to September 11, 2001. 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, and it does not apply to National Guard personnel when under the direct command of states’ governors. Congress has authorized DOD to use its personnel and equipment in a number of circumstances, for example, to: assist with drug interdiction and other law enforcement functions (10 U.S.C. §124 and 10 U.S.C. §§371-378 (excluding 375)); protect civil rights or property, or suppress insurrection (the Insurrection 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 some 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 a review of 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, Congress directed DOD to review and report on the legal implications of members of the armed forces operating on U.S. territory and the potential legal impediments affecting DOD’s role in supporting homeland security. In March 2003, the Commander of U.S. Northern Command stated, “We believe the Act, as amended, provides the authority we need to do our job, and no modification is needed at this time.” According to DOD, on May 29, 2003, DOD informed Congress of the results of its legal review, which concluded that the President has sufficient authority to order the military to provide military support to civilian law enforcement authorities, when necessary. DOD does not believe that the Posse Comitatus Act would in any way impede the nature or timeliness of its response. In response to adjustments in its strategic focus, DOD has created new organizations and is implementing a campaign plan for domestic military missions, but it has not evaluated or adjusted its force structure. The terrorist attacks of September 11, 2001, required that the nation, including DOD, take extraordinary actions on that day. In the new security environment, DOD continues to defend the United States at home against terrorists, which are nontraditional adversaries. We could not assess the adequacy of the organizational changes and the plan at the time of our review because the organizations were not yet fully operational, and the campaign plan was only recently completed. However, DOD has not evaluated its force structure for domestic operations and these forces remain organized, trained, and equipped to fight overseas military adversaries. Domestic military missions provide less opportunity to practice varied skills required for combat and consequently offer limited training value; thus, some forces have not been tailored to perform their domestic military missions. In addition, servicemembers are experiencing high personnel tempo. These factors indicate that the current mission approach may not be sustainable and risks eroding 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 were not yet fully operational at the time of our review, because they had only recently been established and were not fully staffed. First, the Senate confirmed the President’s nominee to be Assistant Secretary of Defense for Homeland Defense in February 2003. The assistant secretary is to provide overall supervision for domestic military missions and military support to U.S. civil authorities. This office was not fully operational at the time our review was completed, with approximately two-thirds of the staff positions vacant. Second, U.S. Northern Command was activated only in October 2002 and was not planned to be fully operational before October 2003. As of mid-April 2003, only 46 percent of U.S. Northern Command’s staff positions had been filled. According to a U.S. Northern Command official, the command was grappling with the need to conduct its ongoing missions while staffing the command’s remaining positions. The activation of U.S. Northern Command provides 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 military forces to defend U.S. territory from land- and sea-based threats while NORAD defended the United States from airborne threats (and still does). The Commander of U.S. Northern Command is also the Commander of NORAD, thereby providing unity of command for air, land, and sea missions. DOD’s planning process requires DOD 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. Since the plan was only recently completed, the services have had little time to determine if training and equipment adjustments were needed to support the plan. DOD has not evaluated or adjusted its force structure, which generally remains organized, trained, and equipped to fight military adversaries overseas. However, some forces are not well tailored to perform domestic military missions. When performing domestic military missions, combat units are unable to maintain proficiency in combat skills through practice in normal training. Domestic missions to date generally have required only basic military skills and thus offered limited training value—which can have an adverse affect on unit readiness. In our review, we found that four Army military police combat units guarding federal installations in the United States could not train for battlefield conditions, as the Army requires. Similarly, Air Force fighter units performing domestic combat air patrols were inhibited from executing the full range of difficult, tactical maneuvers with the frequency that the Air Force requires. Moreover, from September 2001 through December 2002, the number of personnel exceeding the established personnel tempo thresholds increased substantially, an indicator that the present force structure may not be sufficient to address the increase in domestic and overseas military missions. To prevent significant near-term attrition from the force, a key concern during periods of high personnel tempo, DOD has used its stop loss authority to prohibit servicemembers affected by the order from leaving the service. Under high personnel tempo, U.S. forces could experience an unsustainable pace that may lead to an erosion of unit readiness for combat if servicemembers leave the service. While on domestic military missions, some servicemembers cannot practice their primary combat training to maintain proficiency. During Operation Noble Eagle, DOD provided enhanced domestic installation security and combat air patrols, both of which generally require only basic military skills but offer little opportunity to practice the varied combat skills needed for wartime proficiency. As a result, military readiness may erode. According to Army and Air Force officials, because combat skills for these units are perishable, to maintain or regain proficiency, a resumption of normal combat training may be required before subsequent overseas deployment. Army training focuses on combat mission performance that replicates battlefield conditions. To acquire the skills necessary for combat, each unit commander establishes a mission essential task list consisting of critical tasks that the unit needs to be proficient on to perform its overseas wartime mission. However, the four military police units that we reviewed were often unable to train and, thus, they were unable to maintain proficiency for their required mission essential tasks due to the long Operation Noble Eagle deployments. For example, one unit could not practice for two of its mission essential tasks—to establish and sustain an internment and resettlement facility, and process and account for internees—that it performs in combat. In another example, two military police units could not practice their combat skills, which include providing battlefield control of roads and logistical pipelines. Instead, the four Army military police units from the active, reserve, and National Guard we reviewed were generally guarding gates, checking identification, inspecting vehicles, and conducting security patrols of critical installation infrastructure, such as command and control centers, and housing, shopping, and recreation areas. Moreover, we found that some Army servicemembers on Operation Noble Eagle deployments used skills unrelated to their normal missions. Consequently, their units’ combat proficiency may be at risk. Specifically, the Army provided over 8,100 Army National Guard personnel from about 100 units to provide installation security at domestic Air Force bases. However, only one unit, a military police unit, had primary skills relevant to the mission; the remaining units were comprised of field artillery, engineer, and infantry personnel that have specialized combat skills such as providing fire support to tactical combat units; rehabilitating the combat zone to enhance lines of supply and communication; and destroying or capturing the enemy or repelling enemy assaults by fire. None of these units needed its combat skills on its Operation Noble Eagle missions. Similarly, the domestic combat air patrol mission represents another instance where servicemembers cannot always practice their primary combat training for proficiency. To maintain their warfighting skills, fighter pilots perform training sorties when not deployed abroad. Training sorties involve the employment of tactical maneuvers, and the use of weapons or weapons simulators against other aircraft or ground targets. For example, an offensive counterair-training sortie is designed to train for destroying, disrupting, or degrading enemy air and missile threats located in enemy territory. When on a domestic combat air patrol, a pilot may gain some training benefit by performing certain activities, such as an aerial refueling or a night landing. However, according to several Air Force officials, domestic combat air patrols do not constitute adequate training for overseas combat missions. For example, one Air Force official said that combat air patrols involve little more than making left turns flying in a circle in contrast to the difficult, tactical, defensive, and offensive maneuvers performed while on a training sortie or possibly on a combat mission. Air Force 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 maintain proficiency for their combat missions. For example, in one of the seven most heavily tasked Air National Guard fighter wings, the average pilot was unable to meet training requirements in 9 out of 13 months between September 2001 and September 2002. Another wing reported that Operation Noble Eagle had resulted in a 5-month period when no training was performed. Even a short-term tasking can inhibit training needed to maintain combat proficiency. According to Air Force officials, three training sorties are generally lost for every short-notice, 4-hour domestic combat air patrol performed. To mitigate the impact on pilot readiness, the Air Force rotates the units tasked to perform domestic combat air patrols when a continuous airborne alert posture is required. In doing so, the Air Force has sought to ensure that all fighter units are able to train sufficiently for overseas combat missions, thereby preserving flexibility in the use of these units for both domestic combat air patrols and for combat missions overseas. However, it is unclear whether managing the force structure in this way fully mitigates the impact on pilot training, particularly during periods of frequently performed domestic combat air patrol missions. According to one Air Force official, under the current force structure, domestic combat air patrols operating at levels experienced in the months after September 11, 2001, would not be sustainable for more than a few weeks before the units began suffering severe training effects and thus an erosion in military readiness. DOD is undertaking planned changes to the Defense Readiness Reporting System, which are designed to assess the impact of homeland defense and civil support missions on the readiness of forces to execute their warfighting mission. In March 2003, we reported that as of January 2003, DOD had not developed an implementation plan for the Defense Readiness Reporting System that contained measurable performance goals, identified resources, suggested performance indicators, or included an evaluation plan to assess progress in developing this system. Even though the new system may have the potential to improve readiness reporting, without an implementation plan there is little assurance that the new system will actually improve readiness assessments by the time of its expected full capability, in 2007. Without such a plan, it will also remain difficult to gauge progress toward meeting the 2007 target date. DOD did not agree with the recommendations from our March 2003 report that it (1) develop an implementation plan with, among other things, performance goals that are objective, quantifiable, and measurable, and (2) provide annual updates to Congress on the new readiness reporting system’s development. However, as stated in the March 2003 report, we retained those two recommendations because we continue to believe that it is important for DOD to develop an implementation plan to gauge progress in developing and implementing the new readiness reporting system and to provide annual updates to Congress. Personnel tempo data indicate that the current mission approach is significantly stressing U.S. forces. Between September 2001 and December 2002, personnel tempo increased dramatically for Army and Air Force personnel due to ongoing missions or commitments around the world and increasing support for Operations Noble Eagle and Enduring Freedom. DOD believes that if servicemembers spend too much time away from home, a risk exists that they will leave the service and that military readiness may ultimately suffer. Personnel tempo is the amount of time that a member of the armed forces is engaged in their official duties that makes it infeasible to spend off duty time at the member’s home, home port (for Navy servicemembers), or in the member’s civilian residence (for reserve components’ personnel). The National Defense Authorization Act for Fiscal Year 2000 requires that DOD formally track and manage for the number of days that each member of the armed forces is deployed, and it established two thresholds— servicemembers deployed more than 182 or 220 days away from home out of the preceding 365 days. The National Defense Authorization Act for Fiscal Year 2001 established a third threshold, which requires that servicemembers who are deployed for 401 or more days out of the preceding 730-day (2-year) period receive a $100 high deployment per diem allowance. DOD data indicate that tempo is high and increasing for active, reserve, and National Guard personnel. For example, in September 2001, over 6,600 Army personnel had exceeded the first threshold, spending 182 to 219 days away from home during the previous 365 days. By December 2002, that number had risen to over 13,000 (of which Army Reserve and Army National Guard personnel represented about 20 percent). During the same period, the number exceeding the second threshold and spending 220 to 365 days away had risen from about 800 to over 18,000 (which was comprised of about 75 percent Army Reserve and Army National Guard personnel), as shown in figure 2. The number of Army personnel exceeding the third threshold of 401 or more days away from home in the preceding 730 days increased slightly, starting at about 650 in September 2002 and rising to about 990 (of which about 35 percent were Army Reserve and Army National Guard personnel) in December 2002. The Air Force reported similar trends. In September 2001, about 2,100 Air Force servicemembers were away from home for 182 to 219 days, but that had risen to about 8,300 (which were comprised of about 75 percent Air Force Reserve and Air National Guard personnel) by December 2002. Also, as with the Army, Air Force servicemembers away 220 to 365 days had risen from about 1,600 to over 22,100 (of which Air Force Reserve and Air National Guard personnel represented about 70 percent), as shown in figure 3. The number of Air Force personnel exceeding the third personnel tempo threshold of 401 or more days away from home in the preceding 730-day period also increased during the latter period of 2002, starting at about 3,700 in September 2002 and rising to more than 8,100 (of which Air Force Reserve and Air National Guard personnel represented about 65 percent) in December 2002. DOD believes that the potential exists for retention problems stemming from high personnel tempo. To prevent servicemembers with key skills from leaving the services, DOD issued 23 orders since September 11, 2001, to prevent erosion in combat capabilities that may stem from attrition, an action known as stop loss authority. These orders affected personnel with designated individual job skills or, in some cases, all of the individuals in specific types of units that were critical for overseas combat and domestic military missions. However, many of the stop loss orders had been terminated since September 11, 2001. For example, the Navy’s individual stop loss order went into effect on April 27, 2003, and subsequently the Navy terminated this order in mid-May 2003. Table 2 shows the estimated number of personnel affected by the stop loss orders in effect as of April 30, 2003. Officials from the four services who manage the implementation of these orders cautioned that they are short-term tools designed to maintain unit-level military readiness for overseas combat and domestic military missions. Moreover, the officials added that the orders are not to be used as a long-term solution to address mismatches or shortfalls in capabilities and requirements, or as a substitute for the routine recruiting, induction, and training of new servicemembers. DOD must balance domestic and overseas missions with a renewed emphasis on homeland defense. Moreover, current operations both home and abroad are stressing the forces, as shown in personnel tempo data. Complicating the situation is the fact that some units are not well structured for their domestic missions, cannot practice the varied skills needed to maintain combat proficiency while performing domestic missions, and receive little training value from their assigned domestic duties. Therefore, military force readiness may erode and future personnel retention problems may develop, if action is not taken to address these problems. We recommend that the Secretary of Defense assess domestic military mission requirements and determine if steps should be taken to structure U.S. forces to better accomplish domestic military missions while maintaining proficiency for overseas combat missions. In written comments on a draft of this report, DOD generally concurred with the need to do an assessment that is expressed in our recommendation. DOD stated that our draft report provides an accurate assessment of DOD’s need to balance its domestic and overseas mission with a renewed emphasis on homeland defense. DOD added that our draft report describes the stress that high operational tempo could have on personnel. However, in its comments, DOD stated that it does not believe that an independent force structure assessment is required to better match force structure to perceived new domestic support requirements; rather, DOD stated that force structure changes should be determined through the ongoing force management processes that will culminate with the fiscal year 2005 Quadrennial Defense Review. If DOD can incorporate a force structure assessment as part of its ongoing force management processes, then it would generally fulfill the intent or our recommendation. However, we believe that DOD should examine the merits of taking actions to alleviate stress on the forces in the near term rather than wait until the fiscal year 2005 Quadrennial Defense Review because the missions causing the stress are continuing. Based on our analysis of personnel tempo trends through December 2002 and on discussions with officials conducting domestic military missions, we believe that U.S. military force readiness may erode because of the poor match between the types of forces needed for the domestic military missions we reviewed, the forces available, and the limited training value derived from the missions. Moreover, future personnel retention problems may develop in the meantime due to the pace of operations, which consequently may become unsustainable. Additionally, current operations in Iraq, which were not considered in our analysis of military personnel tempo data, can be expected to impact a significant portion of the military force structure for the foreseeable future. Lastly, homeland defense missions are another factor of military personnel tempo because these missions are ongoing. Therefore, we believe our recommendation is valid as originally drafted. DOD’s comments are reprinted in appendix II, along with our evaluation of them. In addition, DOD provided technical comments, which we incorporated as appropriate. We conducted our review from July 2002 through April 2003 in accordance with generally accepted government auditing standards. Unless you publicly announce its contents earlier, we plan no further distribution of this report until 30 days from its issue date. At that time, we will send copies of this report to other appropriate congressional committees and the Secretary of Defense. We will also make copies available to other interested parties upon request. In addition, the report will be available at no charge on the GAO Web site at http://www.gao.gov. If you or your staff have any questions about this report please call me at (202) 512-6020 or e-mail me at deckerr@gao.gov. The GAO contact and key contributors are listed in appendix III. To determine how the Department of Defense’s (DOD) military and nonmilitary missions differ and how they have changed since September 11, 2001, we conducted in-depth interviews with officials from the Office of the Secretary of Defense, including but not limited to the Office of the Executive Secretary, Office of the Special Assistant for Homeland Security, the Office of the Assistant Secretary of Defense for Homeland Defense, the Office of the Assistant Secretary of Defense for Reserve Affairs, and the General Counsel; the Joint Staff’s J-3 Directorate for Operations and J-5 Directorate for Strategic Plans and Policy; U.S. Joint Forces Command’s Joint Force Headquarters for Homeland Security; the Director of Military Support; the U.S. Army Reserve Command; the National Guard Bureau Homeland Defense Office; and the Army and Air National Guard. We visited and met with officials from U.S. Northern Command, who also provided detailed responses to our written questions, which we analyzed and used to continue a dialogue with the officials. We also analyzed documents prepared by U.S. Northern Command and the Joint Force Headquarters for Homeland Security. We reviewed DOD directives that govern civil support missions, including DOD Directive 3025.1 Military Support to Civil Authorities issued January 15, 1993, and DOD Directive 3025.15 Military Assistance to Civil Authorities issued February 18, 1997. Also, we analyzed Director of Military Support data for fiscal years 2001 and 2002 to learn about the types of nonmilitary support that DOD provided to federal agencies. To better understand DOD’s missions, we reviewed key documents such as the Secretary of Defense’s Annual Report to the President and the Congress for 2002, the National Strategy for Homeland Security, The National Security Strategy of the United States, the 2001 Quadrennial Defense Review Report, and the defense strategy issued as part of the 2001 Quadrennial Defense Review Report. To more fully understand the legal context of DOD’s civil support missions in the United States, we reviewed laws and defense directives relevant to DOD’s civilian support activities. We also examined the 1878 Posse Comitatus Act and its restrictions on direct DOD assistance to civilian law enforcement. We identified and examined a series of statutory exceptions to the Posse Comitatus Act. In addition, we reviewed DOD’s directives governing civil support missions and assistance to law enforcement to identify DOD’s criteria for accepting or rejecting requests for such assistance. To assess whether DOD’s organizations, plans, and force structure are adequate to address domestic military missions, we identified DOD’s new organizations and responsibilities with DOD officials and visited the U.S. Northern Command, reviewed plans, and compared the types of domestic missions performed by the forces with their primary missions. Specifically for DOD’s organizations, we reviewed appropriate documents, including the U.S. Northern Command Campaign Plan and the April 2002 revision to the Unified Command Plan, and we discussed organizational changes with knowledgeable officials throughout DOD. We also attended several congressional hearings that addressed the establishment of new organizations and their roles and responsibilities. With respect to understanding how plans address DOD’s domestic missions, we reviewed our prior audit work related to the review of the 2001 Quadrennial Defense Review Report and risk management. Also, we discussed DOD’s planning process with an official at the Office of the Secretary of Defense and at U.S. Northern Command and we discussed the development of the campaign plan with U.S. Northern Command officials. To obtain an understanding of whether forces performing domestic military missions are tailored to perform these missions, we selected two Operation Noble Eagle missions performed in the continental United States by DOD forces since September 11, 2001. Specifically, we reviewed installation security provided by Army military police units and combat air patrols flown by Air Force fighter units. We selected these specific missions because: (1) Joint Force Headquarters for Homeland Security officials indicated that Army military police combat units were deploying at high rates due to the events of September 11, 2001, and (2) the combat air patrol mission was the first domestic military mission performed under Operation Noble Eagle. To understand installation security missions, we interviewed officials at U.S. Forces Command; the U.S. Army Reserve Command; and the U.S. Army Training and Doctrine Command. We also visited and interviewed officials at military police combat units that deployed for these missions, including an Army active duty combat support company, an Army Reserve internment and resettlement battalion, and an Army National Guard guard company. We also conducted a 2-day videoconference with command officials from an Army National Guard combat support company. We analyzed documentation such as briefings, mission orders, and training documents from the four units. We selected these military police units judgmentally based on the deployment data received from U.S. Forces Command, taking into consideration the number of days the units had performed installation security; the number of personnel deployed on the missions; the type of military police unit involved; whether the unit was from the active Army, Army Reserve, or Army National Guard; and whether the unit completed its mission or would do so prior to the conclusion of our review. To better understand whether the skills required for installation security were well matched to the unit’s primary wartime missions, we compared the required combat training for these units to the types of duties they routinely performed for enhanced installation security. Further, we reviewed Army training regulations and manuals. We also analyzed data pertaining to the Army National Guard deployments to Air Force installations in the continental United States. We determined the types of units that deployed on these missions, including those most frequently deployed, and we examined the primary combat training requirements these units must perform to maintain combat proficiency in their particular specialties. To gain first-hand information about the combat air patrols, we interviewed officials at active duty Air Force and Air National Guard units that performed combat air patrol missions, and analyzed extensive operational, training, and maintenance data. To gain an understanding about operational requirements and command and control issues for combat air patrol missions, we interviewed officials at the Department of the Air Force; the Air National Guard; the Air Force Reserve Command; the Air Combat Command; the Continental United States Region, North American Aerospace Defense Command; and North American Aerospace Defense Command. We selected units to visit based on their participation in combat air patrols since September 11, 2001. We obtained and analyzed flying hours and sortie data for fiscal years 2001 and 2002 for fighter (F15 and F16) wings from Air Combat Command, the Air National Guard, and the Air Force Reserve Command. We also obtained and reviewed Air Force training instructions and unit training performance reports. To determine if military personnel experienced increases in time away from home while performing official military duties, we reviewed data for personnel tempo for each of the military services and their respective reserve components for the period October 1, 2000, through December 31, 2002 (the latest data available). The services report their data to the Defense Manpower Data Center under the direction of the Under Secretary of Defense for Personnel and Readiness. We obtained the Army’s data directly from the Army Personnel Command because at the time of our review, the Defense Manpower Data Center did not have the Army’s recent data in its information management system. To gain further insight into the personnel tempo data, we conducted in-depth interviews with officials from the Office of the Secretary of Defense for Personnel and Readiness, the Defense Manpower Data Center, and the Departments of the Army and the Air Force. We also reviewed DOD’s use of stop loss authority by obtaining the stop loss orders and estimates of affected personnel from officials in the Deputy Under Secretary of Defense for Military Personnel Policy, and each of the military services. We discussed the estimates with the officials to determine the most appropriate way to demonstrate the impacts of stop loss orders. We reviewed the data provided by the Army, Army Reserve, Army National Guard, Air National Guard, Air Force, Defense Manpower Data Center, and Army Personnel Command for completeness and reliability. For the analysis of flying hours and military police deployments, we found and corrected some errors in the data. Specifically, we found errors in the Air Force’s flying hour records and corrected the data by incorporating data provided by the affected unit. For military police deployments we found duplicate deployments in some cases and eliminated the duplicate records. For the analysis of Air Force, Marine Corps, Army, and Navy personnel tempo data, we found and corrected some errors where possible, and did not use the data or specific fields where the data were unreliable or we could not correct the problems. Specifically, for the Air Force data, we eliminated duplicate records and deleted all records of personnel who had overlapping duty dates. For all services, where the personnel tempo end date was missing, we assumed the personnel were still away from home and set the end date to a date after our analytic period. To the extent that the missing date represents completed duties where the end date had not been entered, we are overstating the number of personnel and the extent of days away from home. Through corroborating evidence from comparisons with other DOD data files and our corrections, we confirmed that the data we used present a reliable depiction of the active Army, Army Reserve, Army National Guard, active Air Force, and Air National Guard units involved in Operation Noble Eagle activities; and Army, Air Force, Navy, and Marine Corps personnel deployments from October 1, 2000, to December 31, 2002. The following are GAO’s comments on the Department of Defense’s letter dated June 30, 2003. 1. DOD stated that it is now studying and implementing significant changes in the force structure to better support civil authorities during domestic events. First, during our audit we were not presented with evidence of such studies as they relate to either civil support or homeland defense missions. Second, in our follow-up conversation with a DOD official concerning this statement, the DOD official did not provide specific information about the scope, content, or completion dates of the studies. Finally, DOD stated that it has adjusted its strategic and operational focus to encompass traditional military threats from hostile states, asymmetric threats posed by terrorists, and asymmetric threats posed by hostile states. Our draft report acknowledged the shifts for traditional military threats and the asymmetric threats posed by terrorists. Based on DOD’s comment, we added asymmetric threats posed by hostile states. 2. DOD stated that it is important for the report to note that DOD military forces are not first responders. Rather, DOD provides support as directed by the President or Secretary of Defense using defense capabilities to assist other federal, state, and local authorities in response to their requests. Additionally, DOD stated that our report fails to emphasize that DOD is not the long-term solution to the nation’s domestic prevention, response, and recovery requirements. Our report clearly states that DOD assesses requests from civil authorities based upon its own criteria from DOD Directive 3025.15, Military Assistance to Civil Authorities, and that DOD has some discretion to accept or reject these requests. Moreover, DOD suggested that we use this opportunity to recommend a solution involving the fostering of a more robust state and local response structure. We disagree. We did not comment on such a solution in our draft report because this type of assessment was outside the scope of our review. Ultimately, the President and Congress will determine the future role of DOD, if any, in domestic response missions. 3. DOD commented that our draft report does not mention the planned changes to the Defense Readiness Reporting System. According to DOD, the system’s changes are designed to assess the impact of homeland defense and civil support missions on the readiness of forces to execute their warfighting mission. At DOD’s request, we have incorporated information about this system on page 17. However, in March 2003, we reported that as of January 2003, DOD had not developed an implementation plan for the Defense Readiness Reporting System that contained measurable performance goals, identified resources, suggested performance indicators, or included an evaluation plan to assess progress in developing this system. 4. DOD commented that our draft report used non-standard terminology, referring to military missions (what DOD calls homeland defense) and nonmilitary missions (support to civil authorities). We added language on page 1 (see footnote 1) to establish the meaning of the terms used in our report. 5. DOD stated that it believes it is not clear that homeland defense and support to civil authorities missions are key factors in high personnel tempo. On the contrary, our draft report acknowledges that overseas missions as well as domestic missions contribute to high personnel tempo. Indeed, current personnel tempo could be even higher than is depicted in our draft report because the data displaying high personnel tempo stemming from participation in homeland defense missions or other deployments after December 2002, or from Operation Iraqi Freedom, were not yet fully available at the time of our review. In addition, the personnel tempo data we received from DOD did not record a servicemember’s assigned operation—for example, Operation Noble Eagle. However, we added a statement to footnote 28 in our report that acknowledges this limitation in the personnel tempo data we received. DOD also commented that since 9/11/01, increased requirements have been driven more significantly by overseas operations in Afghanistan, Iraq, and elsewhere in the war on terrorism. While DOD may be correct, our report discussed personnel tempo, not requirements. Personnel tempo refers to the amount of time during which a member of the armed forces is engaged in official duties at a location that makes it infeasible to spend off duty time at the servicemember’s home, homeport (for Navy servicemembers), or civilian residence (for reserve components’ personnel). Therefore, we stand by our finding that high personnel tempo is an indicator that present force structure may not be sufficient to address the increase in domestic and overseas military missions and could lead to an erosion of unit readiness. Lastly, because the assessment of rotating units to maintain combat readiness was outside the scope of our review, we could not evaluate DOD’s statements. 6. DOD commented that activities such as mobilization and preparation for war would almost certainly have an impact on the resources available to respond to homeland defense and support to civil authorities missions. DOD added that our draft report leaves the inaccurate impression that this situation is the norm. However, DOD did not specifically point out where the report suggested such an interpretation. We disagree that our report leaves an inaccurate impression, because it does not have statements implying this cause and effect. However, because servicemembers cannot be in both domestic and overseas locations at the same time, we believe that mobilization and preparation for any one mission, even including war, will necessarily make them unavailable for other missions. DOD also commented that it is important to note that, even during Operation Iraqi Freedom, over 200,000 soldiers and airmen were still available after the mobilization. We agree that a significant number of personnel have not been mobilized even during Operation Iraqi Freedom, but it is unclear what DOD’s figure means. DOD did not provide evidence to support this figure, and we believe that, in any case, it is tangential to our point—that, in general, some forces are not optimally suited to perform domestic military missions. We found that some forces’ skills are mismatched with the needs of domestic military missions and that these forces lose critical training opportunities. Thus, DOD’s statement that 200,000 servicemembers were available does not necessarily signify that these members are well suited for the missions at hand. Lastly, we did not discuss overseas missions at length in this report, because the report reviewed DOD’s domestic military missions. 7. DOD commented that when identifying Title 10 statutes that allow federal forces to perform domestic law enforcement missions, the report does not make clear that these missions are based on worst case scenarios and are not the norm. We agree that the use of federal forces to perform law enforcement missions is not the norm. As suggested by each of the authorized uses of federal forces in domestic law enforcement roles that we identified, such uses are in fact the exception rather than the rule. DOD is correct when it states that it undertakes missions to support civil authorities at the direction of the President or the Secretary of Defense, and, as DOD has pointed out, these missions may be undertaken upon requests for assistance from civil authorities. 8. DOD disagreed with our statement on page 14 that domestic military missions to date have offered limited training value because these missions generally have required only basic military skills. DOD stated that basic military skills require practice, just as do the more sophisticated skills. We agree that basic skills also need practice, and our report made clear that, while performing Operation Noble Eagle missions (such as domestic installation security and combat air patrols), forces are able to employ basic military skills. However, our discussions with service officials revealed that servicemembers were inhibited from executing the full range of difficult tactical maneuvers or from replicating battlefield conditions while deployed on Operation Noble Eagle missions. Moreover, we reviewed DOD training requirements for all the military skills of these forces, both basic and advanced, as well as the DOD requirements for their frequency of practice in order to ensure proficiency. Also, DOD asserts that there will be ample opportunity to increase readiness prior to operational employment. However, DOD did not explain how it could predict the amount of time available to prepare for a future contingency. In any case, based on DOD’s requirements, we have concluded that overall combat readiness may erode. In addition, based on the length or frequency for Operation Noble Eagle deployments that we reviewed, we concluded that although basic military skills have been frequently practiced, combat skills have not generally been practiced. As a result, the combat proficiency of many servicemembers could be jeopardized. Moreover, because DOD did not provide specific criteria for what constitutes the limited scope and duration of domestic missions, we cannot address these comments. Finally, Operation Noble Eagle began on 9/11/01, is continuing, and has no known end in sight, which raises questions about whether this is a “limited duration” mission. Therefore, we stand by our report as originally drafted. 9. In its comments, DOD pointed out that we concluded (now on p. 23) that some units are not well structured for their domestic missions, cannot practice the varied skills needed to maintain combat proficiency while performing domestic missions, and receive little training value from their assigned domestic missions. DOD then asserts that a temporary reduction in a unit’s effectiveness for its primary mission due to homeland security or peacekeeping missions is not necessarily a bad thing. A key DOD official explained to us that effectiveness refers to the extent to which a unit was successful in completing a mission to which it was assigned. However, we did not evaluate the extent to which any military units were successful in completing assigned missions, thus DOD’s comment missed our point. We believe that a unit’s readiness may erode in the future from performing a mission for which it was not designed. DOD also asserted that the ability of units to prepare for and execute a variety of missions with inherent capability adds flexibility. While DOD is apparently asserting that the missions we reviewed are adding flexibility and enhancing responsiveness, DOD did not explain how practicing the basic skills of flying aircraft and standing guard adds flexibility. Consequently, we stand by our conclusion. 10. DOD commented that the report confused the interpretation and application of the Posse Comitatus Act with regard to the use of the military to enforce the laws of the United States. We disagree. Our report identified and summarized laws associated with the 1878 Posse Comitatus Act. We explained the laws’ impact on requests for DOD assistance in domestic law enforcement operations. We also reported that DOD does not believe the act impedes the nature or timeliness of its response. 11. DOD commented that our report indicated that DOD did not complete a congressionally directed legal review on the use of military forces in the United States and any legal impediments affecting DOD’s role in supporting homeland security. We have updated our report to reflect information that DOD has recently provided to us, although DOD did not provide this report to us. In addition to the person named above, Deborah Colantonio, Richard K. Geiger, Kevin L. O’Neill, William J. Rigazio, Susan K. Woodward, Michael C. Zola, Rebecca Shea, and Arthur L. James Jr. also made key contributions to this report. Homeland Defense: Preliminary Observations on How Overseas and Domestic Missions Impact DOD Forces. GAO-03-677T. Washington, D.C.: April 29, 2003. Combating Terrorism: Observations on National Strategies Related to Terrorism. GAO-03-519T. Washington, D.C.: March 3, 2003. Major Management Challenges and Program Risks: Department of Homeland Security. GAO-03-102. Washington, D.C.: January 2003. Homeland Security: Management Challenges Facing Federal Leadership. GAO-03-260. Washington, D.C.: December 20, 2002. Homeland Security: Effective Intergovernmental Coordination Is Key to Success. GAO-02-1013T. Washington, D.C.: August 23, 2002. Reserve Forces: DOD Actions Needed to Better Manage Relations between Reservists and Their Employers. GAO-02-608. Washington, D.C.: June 13, 2002. Homeland Security: Key Elements to Unify Efforts Are Underway but Uncertainty Remains. GAO-02-610. Washington, D.C.: June 7, 2002. Homeland Security: A Risk Management Approach Can Guide Preparedness Efforts. GAO-02-208T. Washington, D.C.: October 31, 2001. Combating Terrorism: Selected Challenges and Related Recommendations. GAO-01-822. Washington, D.C.: September 20, 2001. Combating Terrorism: Observations on Options to Improve the Federal Response. GAO-01-660T. Washington, D.C.: April 24, 2001. Combating Terrorism: Comments on Counterterrorism Leadership and National Strategy. GAO-01-556T. Washington, D.C.: March 27, 2001. Military Personnel: Full Extent of Support to Civil Authorities Unknown but Unlikely to Adversely Impact Retention. GAO-01-9. Washington, D.C.: January 26, 2001. Combating Terrorism: Federal Response Teams Provide Varied Capabilities: Opportunities Remain to Improve Coordination. GAO-01-14. Washington, D.C.: November 30, 2000. Combating Terrorism: Linking Threats to Strategies and Resources. GAO/T-NSIAD-00-218. Washington, D.C.: July 26, 2000. Combating Terrorism: Observations on the Threat of Chemical and Biological Terrorism. GAO/T-NSIAD-00-50. Washington, D.C.: October 20, 1999. Combating Terrorism: Need for Comprehensive Threat and Risk Assessments of Chemical and Biological Attacks. GAO/NSIAD-99-163. Washington, D.C.: September 7, 1999. Combating Terrorism: Issues to Be Resolved to Improve Counterterrorism Operations. GAO/NSIAD-99-135. Washington, D.C.: May 13, 1999. Combating Terrorism: Observations on Federal Spending to Combat Terrorism. GAO/T-NSIAD/GGD-99-107. Washington, D.C.: March 11, 1999. Combating Terrorism: Observations on Crosscutting Issues. GAO/T-NSIAD-98-164. Washington, D.C.: April 23, 1998. Combating Terrorism: Threat and Risk Assessments Can Help Prioritize and Target Program Investments. GAO/NSIAD-98-74. Washington, D.C.: April 9, 1998. Combating Terrorism: Spending on Governmentwide Programs Requires Better Management and Coordination. GAO/NSIAD-98-39. Washington, D.C.: December 1, 1997. Combating Terrorism: Federal Agencies’ Efforts to Implement National Policy and Strategy. GAO/NSIAD-97-254. Washington, D.C.: September 26, 1997.

Summary: The way in which the federal government views the defense of the United States has dramatically changed since September 11, 2001. Consequently, the Department of Defense (DOD) has adjusted its strategic and operational focus to encompass not only traditional military concerns posed by hostile states overseas but also the asymmetric threats directed at our homeland by both terrorists and hostile states. GAO was asked to review DOD's domestic missions, including (1) how DOD's military and nonmilitary missions differ; (2) how DOD's military and nonmilitary missions have changed since September 11, 2001; (3) how the 1878 Posse Comitatus Act affects DOD's nonmilitary missions; and (4) the extent to which DOD's organizations, plans, and forces are adequate for domestic military missions and the consequent sustainability of the current mission approach. DOD's military and nonmilitary missions differ in terms of roles, duration, acceptance, and capabilities normally employed. The threat of terrorism has altered some military operations. For example, as of September 11, 2001, the North American Aerospace Defense Command orders combat air patrols over U.S. cities to prevent terrorist attacks. The 1878 Posse Comitatus Act prohibits the direct use of federal military troops in domestic civilian law enforcement, except where authorized by the Constitution or acts of Congress. Congress has expressly authorized the use of the military in certain situations such as to assist with terrorist incidents involving weapons of mass destruction. DOD has established new organizations (such as U.S. Northern Command) and implemented a campaign plan for domestic military missions, but it has not evaluated or adjusted its force structure. GAO did not assess the adequacy of the new organizations or the campaign plan because the organizations were not yet fully operational, and the campaign plan was only recently completed. DOD's force structure is not well tailored to perform domestic military missions and may not be able to sustain the high pace of operations that preceded and followed the attacks on September 11, 2001. While on domestic military missions, combat units are unable to maintain proficiency because these missions provide less opportunity to practice the varied skills required for combat and consequently offer little training value. In addition, from September 2001 through December 2002, the number of servicemembers exceeding the established personnel tempo thresholds increased substantially, indicating that the present force structure may not be sufficient to address the increase in domestic and overseas military missions. As a result, U.S. forces could experience an unsustainable pace that could significantly erode their readiness to perform combat missions and impact future personnel retention.