As of June 30, 2017, the UN had carried out 71 peacekeeping operations since 1948, and had 16 active UN peacekeeping operations worldwide. Eight of these UN peacekeeping operations were in sub-Saharan Africa (see fig. 1). In their earliest days, UN peacekeeping operations were primarily military in nature and limited to monitoring cease-fire agreements and stabilizing situations on the ground while political efforts were being made to resolve conflicts. Today, in response to increasingly complex situations in which conflicts may be internal, involve many parties, and include civilians as deliberate targets, UN peacekeeping operations are more commonly “multidimensional”—deploying civilian and police personnel in addition to military personnel. Multidimensional peacekeeping operations seek to create a secure and stable environment while working with national authorities and actors to make sure the peace agreement or political process is implemented. According to the UN, multidimensional peacekeeping operations are designed to protect civilians and often assist in the disarmament, demobilization and reintegration of former combatants; support the organization of elections; protect and promote human rights; and assist in restoring the rule of law. Figure 2 shows examples of UN peacekeepers serving in different capacities as part of MINUSCA in Bangui, CAR. Each UN peacekeeping operation, including its mandated size and tasks, is authorized through a UN Security Council resolution. The operation’s budget and resources are subject to General Assembly approval. The UN’s approved budget for global peacekeeping operations in UN fiscal year 2017 was about $7.9 billion. Individual operation budgets ranged from about $36 million for the peacekeeping operation in Kosovo to more than $1.2 billion for the peacekeeping operation in the Democratic Republic of the Congo (see table 1). The UN reported in June 2017 that it maintained 95,544 uniformed peacekeepers, 5,004 international civilians, 10,149 local civilians, and 1,597 UN volunteers in support of its operations around the world. According to UN documents, civilian peacekeeping personnel are generally recruited to peacekeeping operations as individuals, while police and military personnel are volunteered by member states to participate as part of their country’s contribution to UN peacekeeping operations. The United States is the largest financial contributor to UN peacekeeping operations. From fiscal years 2014 to 2017, the United States contributed an average of about $2.1 billion per year to these operations. The UN General Assembly sets the assessment levels for UN member contributions to peacekeeping operations every 3 years. The United States’ assessment has averaged about 28.5 percent of the UN peacekeeping budget; however, Congress has authorized payment with appropriated funds at about 27 percent for U.S. fiscal years 2014 through 2016, and 25 percent for U.S. fiscal year 2017. In April 2014, UN Security Council Resolution 2149 established MINUSCA following escalating sectarian violence in CAR that resulted in the destruction of state institutions, thousands of deaths, and 2.5 million people—more than half of CAR’s entire population—in need of humanitarian aid, according to a UN report. The conflict also resulted in 174,000 people being internally displaced and over 400,000 fleeing to neighboring countries, according to the UN report. MINUSCA’s tasks include protecting civilians, given the security, humanitarian, human rights, and political crisis in CAR; supporting the implementation of the transition process, including efforts to extend state authority and preserve territorial integrity; facilitating the delivery of humanitarian assistance and promoting and protecting human rights; supporting justice and the rule of law; and facilitating the disarmament, demobilization, reintegration, and repatriation processes. On November 15, 2017, UN Security Council Resolution 2387 (2017) extended MINUSCA’s mandate for a fourth time, through November 15, 2018. MINUSCA’s approved personnel levels for UN fiscal year 2017 comprised 10,750 military personnel, 400 individual police officers, and 1,680 formed police unit personnel, as well as 790 international civilian and 696 national civilian personnel, 238 UN volunteers, and 40 government- provided personnel, according to a UN Secretary-General report. Table 2 shows average annual personnel deployment for MINUSCA and the number of authorized positions for the first 3 full fiscal years of the operation. Based on data and other input from the UN, DOD, and State, we estimate that it would cost the United States more than twice as much as it would cost the UN to implement a hypothetical operation comparable to MINUSCA, the ongoing UN operation in the Central African Republic (CAR). In addition, the estimated cost of a U.S. operation in CAR far exceeds U.S. contributions to MINUSCA. Based on an estimate we developed in conjunction with DOD and State officials, a hypothetical, comparable U.S. operation would likely cost nearly $5.7 billion, more than twice as much as MINUSCA, the ongoing UN operation in CAR. Our comparison covers the time from which MINUSCA was established in April 2014 through the end of UN fiscal year 2017, which ended on June 30, 2017—a total of 3 years and 3 months, the first 39 months of MINUSCA. Over this time period, UN costs for MINUSCA totaled approximately $2.4 billion. Using roughly the same basic parameters for MINUSCA, including similar deployment levels of military and civilian personnel over the same time period, in consultation with DOD and State officials, we estimate that a comparable, hypothetical U.S. operation would likely cost nearly $5.7 billion, more than twice the UN cost for MINUSCA (see table 3 for a detailed comparison of estimated U.S. costs and actual UN costs). This estimate does not include, among other things, the cost for State diplomatic security and office space for civilian staff, the inclusion of which could further increase the total estimated U.S. cost for such an operation. During the same time period, from April 10, 2014 through June 30, 2017, the United States contributed approximately $700 million to the UN to support MINUSCA. Therefore, the estimated cost of a U.S. operation (nearly $5.7 billion) would be almost eight times greater than the United States’ contribution to MINUSCA. See figure 3 for a comparison of these costs with the U.S. estimate. Various factors contribute to the differences in costs between actual UN expenditures for MINUSCA from April 10, 2014 through June 30, 2017— the first 39 months of MINUSCA—and a hypothetical, comparable U.S. operation over the same time period, including disparities in the cost of sourcing and transporting equipment and supplies, staffing and compensating military and police personnel, and maintaining facilities and communications and intelligence systems. These disparities reflect operational, structural, and doctrinal differences in the way the United States likely would undertake a hypothetical, comparable operation, should such an operation be deemed in the U.S. national interest. High U.S. costs to source and transport supplies and equipment to the Central African Republic (CAR) contribute to the difference between our cost estimate for the hypothetical U.S. peacekeeping operation and the UN’s actual costs for MINUSCA. In the hypothetical U.S. operation, based on input from DOD and IDA officials and the output of the IDA cost estimating tool, the United States would fly in most of its consumable supplies from outside CAR. Specifically, materials such as water, ice, food, and other subsistence items would be airlifted into CAR from Italy, a supply location validated as reasonable by DOD and IDA officials given its proximity to the operation and because MINUSCA relies on a UN global service center there, one of two such UN centers in Europe. The estimated U.S. cost of airlifting water alone over the 39-month time period for the hypothetical operation would total nearly $700 million. The United States would still deploy its equipment and personnel to CAR from the United States, at a cost of nearly $600 million. Transportation of equipment and supplies within CAR would cost an additional estimated $316 million. In contrast, the UN does not fly in water or consumables on the same scale as the United States would in the hypothetical operation. Instead, the UN relies on some in-country or local infrastructure and consumables. Military and formed police unit equipment is provided by the troop- and police-contributing countries. The UN reimburses these countries for equipment at set rates. The UN cost of reimbursing countries for deploying their equipment to CAR likely would be less than the amount the United States would spend on airlifting the equipment to CAR alone. For example, the UN cost of freight, deployment, and country reimbursements for military and formed police equipment was approximately $229 million over a 2-year period (July 2014 through June 2016), while in the hypothetical operation the U.S. cost of deploying equipment alone would be over $382 million, which is about $154 million more than the UN cost over a similar 2-year period (September 2014 through August 2016). The United States would staff and compensate its military and police personnel differently than the UN, leading to differences between the estimated U.S. costs and actual UN costs. While neither the hypothetical U.S. cost estimate nor UN expenditures include the cost of salaries for active duty personnel or troops contributed by other countries, respectively, the United States would bear the additional cost of salaries for the share of personnel drawn from military reserves. According to DOD officials, 10 percent of infantry unit personnel would have been reservist personnel in a hypothetical, comparable U.S. operation, based on the average ratio of active to reserve personnel deployed by the United States in fiscal years 2015 through 2017, roughly the same time period as the first 39 months of MINUSCA. As a result, the total estimated cost of the hypothetical U.S. operation reflects the additional U.S. expense of paying full salaries and hardship duty pay for U.S. reservist military personnel. The estimate also includes the incremental costs the United States would incur for deploying active duty military personnel, including hardship duty pay that is not incurred when those personnel are in the United States. For military troops deployed to MINUSCA, the UN pays a standard troop cost reimbursement to the troop-contributing countries, which is intended also to cover incremental expenses but not the cost of troops’ salaries. U.S. costs for civilian police also are significantly higher than UN costs. The United States would pay over $167 million for U.S. civilian police for the duration of the hypothetical operation, while the UN spent $41 million on its individual police officers over the same time frame. The U.S. estimate includes the cost of police salaries and the additional costs of deployment, whereas UN costs for deploying individual police officers do not include salaries, which are borne by the police-contributing countries. Higher U.S. standards for certain aspects of the hypothetical peacekeeping operation in CAR would contribute to costs that exceed those of MINUSCA. Facilities. The higher estimated U.S. costs reflect higher U.S. standards for facilities, according to State officials. The U.S. cost estimate includes more than $1.1 billion for facilities and related costs, which include facility maintenance, food service, laundry, management and administration, and residential leases for civilian personnel. In contrast, the actual UN cost for facilities as part of MINUSCA totaled $292 million over the same time period. Communications and intelligence systems. The United States incurs costs associated with meeting U.S. intelligence standards that are not part of UN operations, which lack comparable intelligence capabilities. The U.S. cost estimate includes $140 million for the cost of Command, Control, Communications, Computers, and Intelligence Systems, which represents additional operational costs to meet higher U.S. standards for U.S. communications and intelligence capabilities. Medical capability. Higher U.S. standards for medical care and medical evacuation capability as compared to the UN are another factor that would contribute to higher U.S. medical costs for a hypothetical operation, according to DOD and State officials. Some UN hospitals may not meet U.S. minimum standards for medical care, according to DOD officials. Although medical costs do not constitute a significant portion of the U.S. cost estimate, estimated U.S. medical costs ($132 million) greatly exceed actual UN medical costs ($8 million) over the same time period. UN and U.S. peacekeeping operations have various relative strengths, according to U.S. and UN officials we met with. Relative strengths of UN peacekeeping operations include international and local acceptance, access to global expertise, and the ability to leverage assistance from multilateral donors and development banks, according to these officials. Relative strengths of U.S. peacekeeping operations would include faster deployment and superior command and control, logistics, intelligence, and counterterrorism capabilities, according to U.S. and UN officials. According to U.S. and UN officials, UN peacekeeping operations benefit from greater international and local acceptance, access to global expertise, and the ability to leverage assistance from multilateral donors and development banks. UN peacekeeping operations also provide indirect benefits to the military capacity of participating countries. International and local acceptance. As a multilateral organization, the UN benefits from greater international and local acceptance for its peacekeeping operations, according to State, DOD, and UN officials. These officials noted that the UN’s multinational character contributes to a reputation for local impartiality. Conversely, the United States acting alone may not be viewed as impartial and could face challenges gaining or maintaining international or local support for peacekeeping operations, according to State and DOD officials. Global expertise. UN officials noted that the UN has unmatched convening power and access to expertise and experience from across the globe to implement the objectives of multidimensional peacekeeping operations. The UN is able to bring in people with subject matter expertise, native language skills, and knowledge of local customs to work for these operations, according to U.S. and UN officials. Leveraging multilateral assistance. U.S. officials told us that the UN is better able to leverage assistance from multilateral donors and multilateral development banks to expand the scope of assistance provided in support of the goals of peacekeeping operations. For example, according to a UN report, MINUSCA is partnering with the UN Development Fund to provide capacity building related to elections, police, courts, and prisons. The report also noted that the UN, European Union, and World Bank supported the Central African Republic government in developing a “National Recovery and Peacebuilding Plan” while harmonizing humanitarian and development funding to ensure complementarity with the UN peacekeeping operation. Developing international military capacity. U.S. officials told us that UN peacekeeping operations provide an indirect benefit of helping to professionalize the military units from many developing countries that contribute troops to the UN. We have previously reported that building military capacity of foreign partners to address security-related threats is an important goal of U.S. national security strategy and foreign policy. According to U.S. and UN officials, the relative strengths of U.S. peacekeeping operations would be faster deployment and superior command and control, logistics, intelligence, and counterterrorism capabilities. Deployment speed. State, DOD, and UN officials highlighted the United States’ ability to deploy troops and police to peacekeeping operations more quickly than the UN. Unlike the U.S. military, which can draw from a ready pool of military personnel, the UN must seek troops from UN member states, which takes time. UN officials told us that the UN faces a shortage of both troops and UN police, which slows deployment. Further, a 2015 report by the UN High-level Panel on Peacekeeping stated that the UN “has struggled to get sufficient forces on the ground quickly enough and relies on under-resourced uniformed capabilities.” The report also stated that aviation, medical, and engineering specialists, among others, are difficult to mobilize in advance of infantry units. Command and control. State, DOD, and UN officials told us that U.S. operations would enable the U.S. military to have direct command and control, whereas UN operations, which are inherently multinational, face challenges with command and control over troops from several different countries. The UN High-level Panel report noted that UN peacekeeping operations’ weak command and control is a well-known constraint that limits the type of operations the UN can undertake. Logistics support. U.S. and UN officials told us that U.S. operations have superior logistics systems. U.S. procurement likely would be faster than UN procurement, which lacks a standing supply chain and, therefore, relies on third-party vendors, according to UN officials. In addition, the UN High Level Panel report stated that UN peacekeeping operations’ logistics systems and structures in the field are under severe strain, which can limit the mobility of these operations. Intelligence capability. U.S. and UN officials agreed that U.S. operations would involve superior intelligence capability. The UN only recently established an intelligence policy—in May 2017—having recognized that some peacekeeping operations had been deployed in fragile political and security environments with asymmetrical and complex threats. However, UN officials acknowledged that the scope of UN intelligence capability remains limited. Counterterrorism capability. DOD officials told us that a U.S. peacekeeping operation would have the capability to include a counterterrorism component and would not be constrained in the use of force, if needed, in response to terrorist threats. UN peacekeeping operations, on the other hand, lack the capabilities and specialized military preparation to engage in counterterrorism operations, according to the UN High-level Panel report. The UN report stated that counterterrorism should be undertaken by the host government, a capable regional force, or an ad hoc coalition authorized by the UN Security Council. According to the UN report, UN peacekeeping operations may engage in proactive and preemptive use of force to protect civilians and UN personnel from threats; however, offensive force to degrade, neutralize or defeat an opponent is a fundamentally different type of posture that should be authorized by the Security Council only under limited and exceptional circumstances. We provided a draft of this report to DOD, State, and the UN for review and comment. DOD provided a letter, reproduced in appendix II, which stated that it had no comments. State did not provide comments. The UN provided technical comments, which we incorporated into our report as appropriate. We are sending copies of this report to the appropriate congressional committees, the Secretaries of Defense and State, and the Secretary- General of the United Nations. In addition, the report is available at no charge on the GAO website at http://www.gao.gov. If you or your staff have any questions about this report, please contact me at (202) 512-9601 or melitot@gao.gov. Contact points for our Offices of Congressional Relations and Public Affairs may be found on the last page of this report. GAO staff who made significant contributions to this report are listed in appendix III. The objectives of this report were to (1) compare the reported costs of a specific United Nations (UN) peacekeeping operation to the estimated costs of a hypothetical, comparable operation implemented by the United States; (2) identify factors that affect cost differences; and (3) identify stakeholder views on the relative strengths of UN and U.S. peacekeeping operations. To compare the reported costs of a specific UN peacekeeping operation to the estimated costs of a hypothetical, comparable operation implemented by the United States, we selected the UN Multidimensional Integrated Stabilization Mission in the Central African Republic (MINUSCA) as a case study. We compared the reported UN expenditures for MINUSCA, which included both military and civilian components, with estimated costs for a hypothetical U.S. operation with a similar level of military and civilian personnel. Our comparison covers a total of 3 years and 3 months—from MINUSCA’s establishment in April 2014 through June 30, 2017, the end of UN fiscal year 2017. We selected MINUSCA because it is in sub-Saharan Africa, where most UN peacekeeping operations established since 2003 have taken place, and has a typical scope and budget compared to other UN peacekeeping operations in sub-Saharan Africa, according to U.S. and UN officials. In addition, MINUSCA is one of the most recent UN peacekeeping operations; thus, initial expenditures for the operation are relatively current. Because the results of our cost comparison are based on a single case study, they cannot be generalized to all UN peacekeeping operations. To determine the UN’s costs for MINUSCA, we analyzed UN budget and expenditure data covering the initial start-up period (April 2014 to June 2014) and the first 3 UN fiscal years (July 1, 2014 to June 30, 2017). We spoke with officials of the UN Departments of Peacekeeping Operations, Field Support, and Management at UN Headquarters in New York, New York, to better understand the characteristics of MINUSCA and the different costs affecting MINUSCA’s budget and expenditures. We assessed UN expenditure data through discussions with cognizant UN officials and a review of external audits of UN budgetary information and found them sufficiently reliable for our purposes. We also analyzed data on U.S. contributions to UN peacekeeping operations for fiscal years 2014 through 2017 from the Department of State’s (State) Bureau of International Organization Affairs to determine total U.S. contributions to MINUSCA, and UN peacekeeping operations overall. To estimate the costs of a hypothetical, comparable operation implemented by the United States, we developed a hypothetical scenario for a U.S. operation based on the MINUSCA budget and supporting documents, assuming deployment of the same number of military, civilian, and police personnel in the Central African Republic (CAR) over the same time period (April 2014 through June 2017). To estimate the military portion of the operation, we interviewed Department of Defense (DOD) officials and staff at the Institute for Defense Analyses (IDA), a DOD-sponsored non-profit corporation involved in developing cost estimates for U.S. contingency operations. The Office of the Undersecretary of Defense-Comptroller and IDA generated a cost estimate for the military components included in the hypothetical operation using the Contingency Operations Support Tool (cost estimating tool). DOD uses this tool to develop cost estimates for all military contingency operations. The cost estimate included only the incremental costs of the operation—those directly attributable to the operation that would not be incurred if the operation did not take place. For example, the estimate produced by the cost estimating tool did not include the direct salaries of active duty personnel as those costs would be incurred by the United States regardless of a possible decision to undertake the hypothetical operation. We assessed the cost estimating tool’s applicability to developing a hypothetical cost estimate for the purposes of this report through discussions with DOD and IDA officials, and compared the tool to the accurate and comprehensive characteristics of a high-quality cost estimate, as described in the GAO Cost Estimating and Assessment Guide. While we found the DOD cost estimating tool generated a sufficiently reliable cost estimate for a hypothetical U.S. peacekeeping operation, we did not assess the overall reliability of the tool or its capability to generate accurate or comprehensive estimates for future U.S. operations. To generate our estimate of U.S. military costs using the DOD’s estimating tool, we used UN military deployment numbers as a baseline for the scale of a hypothetical, comparable U.S. peacekeeping operation, while using unit sizes and rotations in deployment that were considered appropriate for the U.S. military, according to DOD and IDA officials. We based the hypothetical U.S. operation, and hence the cost estimate, on the following assumptions, which correspond approximately with MINUSCA’s actual UN personnel deployments: Theater of operation: Central African Republic (CAR) Type of operation: military contingency Operation time frame: April 10, 2014 through June 30, 2017 Military contingents: as of June 30, 2017, 11,495 total personnel Infantry: 10 units of 630-785 personnel per unit, approximately 90 percent active duty / 10 percent reserves Communication / signals: 1 unit, 124 personnel per unit Engineering: 4 units, 200 personnel per unit Military police: 1 unit, 120 personnel per unit Formed police units (military police): 12 units, 140 personnel per Hospital / medical: 1 level III hospital, 248 beds, 495 personnel Helicopter units: 2 UH-60 C3 units, 1 MH-60M Assault attack helicopter unit, 100 personnel per unit Quick reaction force: 1 unit, 160 personnel per unit Special forces: 1 tactical civilian affairs unit, 1 Marine special operations intelligence unit, 160 personnel per unit Unmanned aerial vehicle: 1 unit, 84 personnel Transportation: 1 heavy transport unit, 120 personnel per unit Operational tempo: 1.0 for all phases of operation and units, except aviation units (set at 1.5) Deployment schedule and phasing: phased deployment, including 14 days for predeployment (e.g., training), 5 days for deployment, 180 days for active duty unit sustainment and 270 days for reserve unit sustainment, 5 days for redeployment, and 0 days for reconstitution Housing: contractor-provided semi-permanent housing Transportation: personnel and equipment transported by airlift from the United States (primarily Fort Hood, Texas), material (such as water, food, and other consumables) transported by airlift from Italy We obtained input on the operational design for the military portion of the cost estimate from DOD officials in the Joint Chiefs of Staff, the Office of the Undersecretary of Defense-Policy, and the Office of the Undersecretary of Defense-Comptroller, and IDA officials. However, the military portions of the scenario and their corresponding cost estimate have some limitations. As a result of rounding for some units, U.S. military personnel numbers do not exactly match the MINUSCA deployment levels. In addition, based on input from DOD officials, we attempted to select military units that would provide an essential function per U.S. common practices while keeping the overall personnel deployment level as close as possible to MINUSCA’s deployment level. An actual U.S. military plan may differ significantly from the UN plan as a result of differences between U.S. and UN military operations, structure, doctrine, and circumstances at the time of the operation. To estimate U.S. civilian costs, we matched the number of U.S. civilian police and personnel to the number serving in MINUSCA. We then estimated the costs of deploying these U.S. civilian personnel in CAR for the same time period as MINUSCA. We did not attempt to determine how the U.S. government would actually implement civilian components of a peacekeeping operation in CAR. To estimate U.S. civilian police costs, we met with State’s Bureau of International Narcotics and Law Enforcement Affairs (INL) to identify State’s costs for civilian police contractors providing police training and technical assistance in sub-Saharan Africa. Based on INL’s input we assumed that the base salary of civilian police would be grade 13, step 5 on the Office of Personnel Management’s general schedule salary tables for federal employees. In addition to the average base salary, we identified other costs—with input from INL—including, among others, personal equipment, travel from the United States, and State’s published allowances specific to CAR for local cost of living, post hardship differential, danger pay, and living quarters. We applied the average cost per officer to the average number of UN civilian police officers deployed in MINUSCA. To estimate U.S. civilian personnel costs, we met with State’s Bureau of Budget and Planning to identify the costs of State Foreign Service officers and locally employed staff, based on the number of UN international and national civilian staff deployed to MINUSCA, respectively. We matched the number of State Foreign Service officers for the U.S. cost estimate to the number of UN international staff in MINUSCA, with input from State to align the grade levels. The estimated costs for Foreign Service officers include average salaries based on State’s Foreign Service salary tables and State’s allowances specific to CAR, including local cost of living, post hardship differential, and danger pay. We also met with State Bureau of Budget and Planning officials to estimate other costs for Foreign Service officers, which we included in our cost estimate, including post assignment travel, administrative support costs, residential furnishings, and residential guards, among others, but we did not assess the reliability of these additional costs provided by State. In addition, State’s Bureau of Overseas Buildings Operations provided the actual costs of residential leases for Foreign Service officers in CAR in fiscal year 2017, which we used to estimate the cost of housing Foreign Service officers in CAR. We also matched the number of State locally employed staff to the number of UN national staff deployed to MINUSCA and added their average salaries and other costs in CAR based on data provided by State’s Bureau of the Comptroller and Global Financial Services. While MINUSCA’s expenditures also included costs for sending an annual average of up to about 200 UN volunteers to CAR, State officials told us that the United States generally would not send volunteers through its assistance efforts to a high-risk post, such as CAR. Therefore, we did not include any costs related to volunteers in the cost estimate. We also did not include costs related to host-government-provided personnel serving in MINUSCA. In addition, UN expenditures included about $7 million for “quick-impact projects” to support local government infrastructure and civil society initiatives. We did not include comparable costs for quick-impact projects in our U.S. cost estimate because we did not have a basis for matching these costs. To identify factors that affect cost differences between MINUSCA and a hypothetical, comparable operation implemented by the United States, we reviewed the U.S. cost estimate generated in conjunction with DOD, IDA, and State officials, and identified significant areas of cost for the United States and the assumptions incorporated in the estimate or factors specified by U.S. officials that drive those costs. We compared the U.S. cost estimate, including these significant areas of cost, to UN costs to identify differences. We interviewed U.S. and UN officials regarding U.S. and UN standards and policies that explain differences between MINUSCA costs and the estimated costs of a U.S. operation. To identify stakeholder views on the relative strengths of UN and U.S. peacekeeping operations, we reviewed UN reports on peacekeeping operations and interviewed UN, DOD, and State officials. In addition, we reviewed GAO’s 2006 report comparing the costs as well as the strengths of a UN peacekeeping operation in Haiti with those of a hypothetical U.S. operation. We conducted our review from February 2017 through February 2018 in accordance with generally accepted government auditing standards. Those standards require that we plan and perform the audit to obtain sufficient, appropriate evidence to provide a reasonable basis for our findings and conclusions based on our audit objectives. We believe that the evidence obtained provides a reasonable basis for our findings and conclusions based on our audit objectives. In addition to the individual named above, Drew Lindsey (Assistant Director), Howard Cott, Juan Pablo Avila-Tournut, Debbie Chung, Martin de Alteriis, Neil Doherty, Jennifer Leotta, Caitlin Mitchell, Elizabeth Repko, and Alex Welsh made significant contributions to this report.

Answer: To promote international peace and security, the UN had 16 ongoing peacekeeping operations worldwide as of June 30, 2017, with a total budget of almost $8 billion in UN fiscal year 2017 and contributions of over 100,000 military, police, and civilian personnel from more than 120 countries. The United States is the largest financial contributor to UN peacekeeping operations, providing an average of about 28 percent of total funding annually. The Department of State Authorities Act, Fiscal Year 2017, includes a provision for GAO to compare the costs, strengths, and limitations of UN and U.S. peacekeeping operations. This report (1) compares the reported costs of a specific UN operation to the estimated costs of a hypothetical, comparable operation implemented by the United States; (2) identifies factors that affect cost differences; and (3) identifies stakeholder views on the relative strengths of UN and U.S. peacekeeping operations. GAO worked with the UN, DOD, and State to generate a cost estimate of a hypothetical U.S.-led operation in the Central African Republic comparable to MINUSCA. GAO developed this estimate using DOD's cost estimating tool for contingency operations and State data on civilian costs, assuming a U.S. operation using roughly the same levels of military and civilian personnel as MINUSCA. The cost estimate should not be construed as suggesting that the United States would likely implement such an operation in the Central African Republic or that it would implement such an operation in the same way. GAO is making no recommendations. Based on United Nations (UN) and Departments of Defense (DOD) and State (State) data, GAO estimates that it would cost the United States more than twice as much as it would cost the UN to implement a hypothetical operation comparable to the UN Multidimensional Integrated Stabilization Mission in the Central African Republic (MINUSCA). MINUSCA cost the UN approximately $2.4 billion for the first 39 months of the operation. GAO estimates that a hypothetical U.S. peacekeeping operation in the Central African Republic of roughly the same size and duration would cost nearly $5.7 billion—almost eight times more than the $700 million the United States contributed to MINUSCA over the same time period. Various factors affect differences between the actual cost of MINUSCA and the estimated cost of a hypothetical, comparable U.S. operation in the Central African Republic. The United States and the UN would source and transport some supplies and equipment differently, affecting the cost of both operations; for example, the United States would airlift water into the Central African Republic, while the UN does not do so to the same extent. The United States also would incur the cost of civilian police and military reservist salaries, while the UN does not pay any troop or police salaries. Finally, some higher standards for facilities, intelligence, and medical services increase the U.S. cost estimate relative to UN costs for similar operational elements. UN and U.S. peacekeeping operations have various relative strengths, according to U.S. and UN officials. These officials said that, because the UN is a multilateral organization, UN peacekeeping operations have international acceptance and are more likely to be viewed as impartial. Officials also said that the UN enjoys global access to expertise and experience, and can leverage assistance from multilateral donors and development banks. Relative strengths of a U.S. peacekeeping operation would include faster deployment and superior command and control, logistics, intelligence, and counterterrorism capability, according to U.S. and UN officials.