Making Peace While Staying Ready for War: The Challenges of U.S. Military Participation in Peace Operations Section 2 of 7
December 1999


In the past decade, U.S. military forces have deployed more frequently to operations other than war. Those operations include missions to provide humanitarian aid, peacekeeping, or the forced cessation of hostilities in areas of conflict. Geopolitical changes and shifts in U.S. foreign and security policies since the end of the Cold War--combined with the U.S. military's ability to project power around the globe--may have contributed to the growing role for the United States in peace operations worldwide. And as the nation's role has grown, so has the amount it spends on such operations.

The U.S. military's increasingly frequent involvement in peace operations raises two key questions. First, are U.S. forces well structured and prepared to meet the challenges involved in carrying out those operations on a routine basis? A military that is designed for conventional war may have trouble continually performing other missions. In particular, it may have trouble providing the right kinds of forces in the required numbers, at the right time, and with the necessary training and equipment for peace operations.

Second, does participating in peace operations detract from the ability of U.S. forces to carry out their primary mission--fighting and winning two nearly simultaneous major theater wars? This question is a relatively recent one. During the Cold War, military planners assumed that forces capable of defending Europe against Soviet aggression would be more than adequate to meet U.S. commitments elsewhere without significantly affecting the military's ability to perform its primary conventional mission. But lately, signs have emerged that peace missions could be taking a toll on the military's ability to pay for routine operations, maintain the combat skills needed for conventional wars, and keep its equipment and personnel ready and available for such wars.

Those challenges are of particular concern to the Army, which provides the majority of funding for peace operations and thousands of ground troops to take part in them. In this analysis, the Congressional Budget Office (CBO) examines four options for restructuring or expanding the active-duty Army to improve its ability to conduct peace operations while staying ready for conventional war. Those options are by no means the only possibilities that exist. Rather, they illustrate the main types of approaches that the Army could consider.


During the Cold War, the U.N. Security Council rarely approved the creation of peace operations. The United Nations implemented only 13 such operations between 1948 and 1978, and none at all from 1979 to 1987. Since 1988, by contrast, 38 peace operations have been established--nearly three times as many as in the previous 40 years.

The U.S. contribution to international peace operations, in both military forces and funds, has risen dramatically during that period. Major deployments of U.S. forces have increased in both frequency and size, reaching roughly 50,000 troops last year (see Summary Figure 1). At the same time, U.S. funding for peace operations has grown substantially--from less than $100 million in 1988 to almost $4 billion 10 years later (see Summary Figure 2). That funding is provided through several vehicles: contributions to the United Nations for peace operations, funding to carry out other international peace missions outside the United Nations' aegis, and appropriations for the Department of Defense (DoD) to support the use of its forces in peace operations.


SOURCE: Congressional Budget Office based on Nina M. Serafino, Military Interventions by U.S. Forces from Vietnam to Bosnia: Background, Outcomes, and "Lessons Learned" for Kosovo, CRS Report for Congress RL30184 (Congressional Research Service, May 20, 1999); Richard F. Grimmett, Instances of Use of United States Armed Forces Abroad, 1798-1999, CRS Report for Congress RL30172 (Congressional Research Service, May 17, 1999); General Accounting Office, Peacekeeping: Assessment of U.S. Participation in the Multinational Force and Observers, GAO/NSIAD-95-113 (August 1995); General Accounting Office, Military Operations: Impact of Operations Other Than War on the Services Varies, GAO/NSIAD-99-69 (May 1999); Alfred B. Prados, Iraq Crisis: U.S. and Allied Forces, CRS Report for Congress 98-120 F (Congressional Research Service, September 2, 1998); Maureen Taft-Morales, Haiti Under President Preval: Issues for Congress, CRS Issue Brief IB96019 (Congressional Research Service, April 15, 1999); Stephen Daggett, Bosnia Peacekeeping: An Assessment of Administration Cost Estimates, CRS Report for Congress 95-1165 F (Congressional Research Service, December 4, 1995); Robert L. Goldich and John C. Schaefer, U.S. Military Operations, 1965-1994 (Not Including Vietnam): Data on Casualties, Decorations, and Personnel Involved, CRS Report for Congress 94-529 F (Congressional Research Service, June 27, 1994); General Accounting Office, Bosnia Peace Operation: Mission, Structure, and Transition Strategy of NATO's Stabilization Force, GAO/NSIAD-99-19 (October 1998); General Accounting Office, Bosnia: Military Services Providing Needed Capabilities but a Few Challenges Emerging, GAO/NSIAD-98-160 (April 1998); and Theodros S. Dagne, Somalia: Prospects for Peace and U.S. Involvement, CRS Report for Congress RL30065 (Congressional Research Service, February 17, 1999).



SOURCE: Congressional Budget Office based on Stephen Daggett and Nina M. Serafino, Costs of Major U.S. Wars and Recent U.S. Overseas Military Operations, CRS Report for Congress 94-995 F (Congressional Research Service, May 5, 1997); Nina M. Serafino, Peacekeeping: Issues of U.S. Military Involvement, CRS Issue Brief IB94040 (Congressional Research Service, September 13, 1999); Nina M. Serafino, The U.S. Military in International Peacekeeping: The Funding Mechanism, CRS Report for Congress 94-95 F (Congressional Research Service, February 8, 1994); General Accounting Office, Peacekeeping: Assessment of U.S. Participation in the Multinational Force and Observers, GAO/NSIAD-95-113 (August 1995); and Marjorie Ann Browne, United Nations Peacekeeping: Issues for Congress, CRS Issue Brief IB90103 (Congressional Research Service, August 20, 1999).



Forces from all of the U.S. military services have taken part in peace missions, but this paper focuses on the ground forces of the Army and Marine Corps. Those two services often play similar roles in peace operations and face similar challenges in preparing for and participating in them. The fundamental differences in their purposes and operational structures affect how the two services respond to those challenges.

Differences Between the Marine Corps and the Army

The Marine Corps's primary purpose is to be ready to respond rapidly to crises around the world. The main tool it uses for rapid response is the Marine expeditionary unit (MEU). A MEU normally has a strength of about 2,200 personnel and is built around a reinforced infantry battalion, a squadron of aircraft, and a service-support group. It requires three to five naval amphibious ships to deploy. The Marine Corps follows a rotation schedule that usually keeps three MEUs deployed around the world at any given time. MEUs have taken part in numerous peace operations, including those in Lebanon, Iraq and Kuwait, Somalia, Haiti, Rwanda, Bosnia, and Kosovo.

The primary purpose of the Army, by contrast, is to fight and win the nation's wars. It does not routinely deploy forces according to a schedule. Instead, the Army responds to each peace operation separately, putting together a package of deploying forces to meet the specific mission. That package is typically built around a core combat unit, which serves as the staff headquarters to coordinate operations; additional support units are attached as needed for the particular mission. Army forces have taken part in many peace operations, including those in the Sinai, Iraq and Kuwait, Somalia, Haiti, Rwanda, Macedonia, Bosnia, and Kosovo.

The Challenges of Participating in Peace Operations

As the number of peace operations involving U.S. forces has increased, so has the complexity of those operations. Today's peace missions are apt to involve such tasks as supervising elections, protecting specified safe areas, interacting extensively with local people, guarding surrendered weapons, ensuring the safe delivery of food supplies, and helping rebuild government agencies or police forces. Many of those tasks are far removed from the ones U.S. forces expect to perform during conventional warfare. The Army and Marine Corps face five major challenges in preparing for such missions: readying personnel for deployment, providing enough of the right kinds of forces, using reservists, training personnel sufficiently for peace operations, and providing the necessary equipment and supplies.

Readying Personnel for Deployment. The Army has had trouble providing units that have a full complement of personnel for some peace operations. During peacetime, Army units are often staffed below the level required for deployment, with personnel constantly coming and going for leave, school or other training, and scheduled job rotations. If a unit has to deploy on relatively short notice, it can borrow personnel from nondeploying units. But those depleted units in turn can suffer a decline in readiness, and the loaned soldiers may not be suited to the positions they are asked to fill.

The Marine Corps faces the same challenge but does not have the same problems as the Army because its personnel practices are geared toward routine, scheduled deployments. The Marines stabilize staffing early in a unit's predeployment training cycle, and personnel remain in the unit until the deployment has ended.

Providing Enough of the Right Kinds of Forces. Certain kinds of combat-support and combat-service-support capabilities--such as transportation, civil affairs, and water purification--are critical for peace operations. As a result, those specialties are in much greater demand for peace operations than other specialties are. In the Army, however, a large percentage of those high-demand specialties are in the reserve component (the National Guard and Reserve). Thus, the few units of that type in the active force can experience frequent deployments, which can have a deleterious effect on their troops' morale and willingness to stay in the service (retention). The Army's experiences in Somalia and Haiti suggest that several specialties in the active Army have inadequate, or just barely adequate, rotation bases to support extended or continuous peace operations. (The rotation base is the units that are available to deploy to an operation.)

Unlike the Army, the Marine Corps has traditionally incorporated rotation-base requirements into its structure. That approach allows the service to maintain its regular MEU deployments and the schedule that keeps marines overseas for six months followed by about 18 months at home. Nevertheless, the Marine Corps has also faced shortages of certain types of personnel, such as linguists and joint communications systems specialists.

Using Reserve Forces. Because the Army has put many of its high-demand support units in the reserve component, it has had to depend increasingly on reservists to help with peace operations. The Army has been able to use some volunteer reservists in those operations, but it has also had to rely on involuntary call-ups to obtain particular specialties or fully staffed reserve units. Both approaches present problems. There is no guarantee that the reservists who are willing to volunteer for a specific peace operation will have the capabilities and training needed for that operation. But calling up reservists involuntarily requires Presidential action, which is sometimes not forthcoming for political reasons. And when it is, frequent or extended use of reservists could ultimately hurt recruitment and retention in the reserves.

Perhaps because the Marine Corps is structured to deploy regularly, it has not had to use reservists frequently in peace operations. But additional deployments or extended operations could force it to do so, in which case it could face the same difficulties that the Army has encountered.

Providing the Right Training for Peace Operations. For many types of units, particularly those whose primary purpose is combat, the skills needed for peace operations may be different from the skills needed to fight conventional wars. Thus, a growing number of military and nonmilitary officials and observers are acknowledging that units likely to take part in peace missions need additional training in the skills particular to those missions.

The Army does not have a standardized training program that all units follow. Instead, commanders choose the training for their unit on the basis of its stated purpose and expected missions. As a result, the amount of routine training that a unit receives in the skills needed for peace operations can vary according to the commander. Marines, in contrast, train for a standard set of missions, which include many tasks that might be required during peace operations.

Providing the Necessary Equipment and Supplies. Forces deploying to peace operations need not only the right personnel and training but also sufficient equipment and supplies. Army units are not always fully equipped in peacetime, and the Army has had some difficulty getting units equipped before they deploy. In past peace missions, some units had to take equipment from nondeploying units, and some did not have the kinds of equipment they needed to operate in the theater to which they were sent.

The Marine Corps has experienced trouble with equipment resupply. Each Marine Corps unit is outfitted by its commander on the basis of probable missions and shipboard space available. One source of resupply is stocks located on board prepositioned supply ships. The peace operation in Somalia exposed some shortcomings in the Corps's prepositioning system involving shortages of certain types of equipment and some equipment that was returned to the ships in poor condition. The Marine Corps is working to fix those problems, and the Army is trying to overcome some of its difficulties with supplies by enhancing its own prepositioning program.


Some observers have questioned whether increased U.S. participation in peace operations has affected the military's ability to carry out its primary combat mission. They worry in particular about the costs of such operations, their effects on the military's warfighting skills and the readiness of its personnel and equipment, and whether the United States will still have enough forces available to fight two major regional wars.

Paying for Peace Operations

Funding peace operations while trying to maintain readiness for conventional war poses challenges for the Department of Defense. The costs to DoD of carrying out peace operations have risen dramatically in the past decade: from about $200 million in 1990 to over $3.6 billion in 1998. DoD covers some of those costs by transferring or reprogramming money within its budget. Some funding is also available from the department's Overseas Contingency Operations Transfer Fund. But DoD must often rely on supplemental appropriations from the Congress to pay for peace operations.

The costs of such operations are small compared with the overall defense budget, and DoD typically does receive supplemental appropriations to cover them. But those appropriations frequently arrive late in the fiscal year, by which time costs have already been incurred. In the meantime, DoD must pay the costs from its regular budget--generally from the operation and maintenance account. That account also pays for such things as training exercises, equipment maintenance, and basic supplies for troops, so diverting funds from it for peace missions can harm U.S. forces' readiness for conventional war.

Maintaining Conventional Warfighting Skills

Another serious challenge for the military services is trying to maintain the conventional warfighting skills of units that participate in peace operations. In some cases, taking part in those operations could actually improve warfighting skills by providing "real" deployment experience and "real" missions, thus increasing a unit's cohesion, leadership skills, and opportunities to work in environments more like those of wartime. Moreover, some of the tasks that troops perform are common to both conventional missions and peace operations. However, participating in peace operations can take time away from training for conventional war. And even when tasks or missions overlap between conventional and peace operations, the manner in which they are performed, the rules of engagement, and the goals are often different.

Army units have shown a clear drop in their training readiness for conventional war after taking part in peace operations. Not surprisingly, those units with the greatest overlap between the conventional warfighting tasks that they train for routinely and the tasks that they performed during peace operations suffered the least degradation in training readiness. The Army has concluded that combat-support and combat-service-support units suffer less degradation in readiness than combat units do.

The Marine Corps does not appear to have had as much trouble as the Army in maintaining training readiness, which probably reflects the difference in the two services' primary roles. Whereas the Army focuses on fighting and winning large conventional wars, the Marine Corps tries to prepare for any mission it might encounter while deployed at sea. As a result, the Marine Corps includes peace operations as one of the 29 missions it routinely trains for.

Maintaining Equipment Readiness

While taking part in peace operations, units need to keep their equipment ready for war. The effect of peace operations on equipment readiness varies, depending on such things as the service, the length and type of peace operation, and the type of unit.

Army units that deploy to peace operations with their own equipment have experienced declines in equipment readiness after operations. However, the units have usually restored their equipment to predeployment levels of readiness within two to four months after their return.

The Marine Corps has also experienced problems with equipment. Some commanders have been reluctant to lend out their troops to clean, recondition, and return equipment borrowed from prepositioned supply ships. And in some instances, after returned equipment was clean and ready to be loaded onto those ships, commanders sent their mechanics to remove parts in order to improve the readiness of their own similar equipment.

Managing Personnel Readiness

Another major problem that the services face is managing personnel readiness (keeping enough people in the right places) while participating in peace operations. In the Army, deployment of a unit can have a negative ripple effect on the personnel readiness of many other units, because the deploying unit may have to borrow individual soldiers or groups of soldiers from nondeploying units. That means the readiness of those nondeploying units will usually decline. Moreover, those units will still be expected to carry out their mission regardless of their decrease in personnel, and in some cases, they may even have to take on some of the duties of the deploying unit.

For its part, a deploying unit can face serious declines in personnel readiness when it returns from a peace operation. Any personnel losses from rotation or leave that were delayed because of the deployment are likely to occur all at once after the unit's return. In addition, soldiers who were temporarily attached to the unit for the deployment generally go back to their original unit. That sudden exodus can have a significant impact on a unit's leadership, institutional memory, and personnel stabilization.

Marine Corps units also experience a sharp decline in personnel readiness following a deployment. When a MEU returns to port after its six-month stint at sea, the readiness of its various components drops significantly as individual marines take leave, change assignments, or undergo training. However, that decline is expected as part of the normal rotational cycle. Another MEU is dispatched to take the place of the returning one, so overall regional capability is not diminished.

Having Enough Forces Available to Fight Two Major Regional Wars

Another significant challenge for the services is ensuring that a sufficient number of forces are available to fight two major regional wars. Participating in peace operations could mean that some forces needed to carry out that national military strategy would not be available to do so. Under current doctrine, if a major regional war erupted, units deployed to a peace operation might need to make the transition to wartime duties quickly. But experience has shown that some forces returning from peace operations need a lengthy recovery period. During that time, they would not be fully ready for conventional war.

That problem is compounded for the Army because of the ad hoc manner in which it creates task forces for peace operations. Nondeployed units that loan personnel to deploying units can suffer a decrease in readiness either directly because of the loss of personnel or indirectly because of the inability to train with their full complement of people. In such a situation, both deployed and some nondeployed units could be unavailable for conventional war. That potential shortage could be an especially great concern to Army planners because the Army's analysis shows that the service would need every deployable unit in its active component, and all of the support units in the reserve component, to fight two major theater wars nearly simultaneously.

Once again, the Marine Corps does not face the same problems as the Army because of the differences in the two services' primary purposes. Whereas the Army's main purpose is to fight and win the nation's wars, the Marine Corps focuses on preparing for a variety of crises. The Marine Corps would have a role in any conventional conflict, but its main purpose would remain to respond to crises whenever needed. Since more than one MEU is deployed at all times, the Marine Corps would still have forces available to respond to a crisis if some of its troops were involved in peace operations.


The Army could take a variety of steps to improve its ability to participate in peace operations while maintaining its readiness for conventional war. CBO examined four potential approaches that represent the range of possibilities that the Army could consider (see Summary Table 1). Each approach has advantages and drawbacks, and some would be easier to implement than others. All of them would involve changes to the active-duty Army. Alternatively, the Army could choose to rely more routinely on reserve units for peace operations. But CBO concluded that such an approach would not address many of the concerns outlined above, and the impact of a fundamental change in the use of the reserves is beyond the scope of this analysis.

Approach Changes Costs or Savings (-)
(Millions of 1999 dollars)


Option I: Cycle the Readiness of Some Active Army Units Select three existing active Army brigades; cycle each through high state of alert every six months; rely on alert brigade to carry out peace operations. n.a. -2
Option II: Reorganize Existing Active Army Forces for Peace Operations Designate four existing brigades to carry out peace operations, and create three standing headquarters to lead them. (Increase size of active Army by 750 to 900.) 30 90
Option III: Convert Some Combat Units in the Active Army into Support Units Convert one active-duty heavy division into support units. 940 -60 to -210
Option IV: Add Forces to the Active Army for Peace Operations Create four brigades designed to carry out peace operations and three standing headquarters to lead them. (Increase size of active Army by 20,000.) n.a. 1,900

SOURCE: Congressional Budget Office.
NOTE: n.a. = not applicable (negligible costs).

Option I: Cycle the Readiness of Some Active Army Units

The Army could put some of its active units on a cyclical readiness schedule similar to the one used for Marine expeditionary units. The units on that schedule would train to a high state of readiness and would be "on call" for a specified amount of time (perhaps six months) to deploy on short notice. During that time, the ready units would be fully manned and equipped, with no personnel rotations or absences for individual training.

One way to carry out this option would be to put three brigades--one from each of three existing divisions--in the pool of units on the new schedule. One brigade would be fully ready and on call to deploy for six months. During that period, the second brigade would be training and preparing to be on call for the next six months. The third brigade, having been on call for the previous six months, would be in a recovery period, when its readiness would be low.

Advantages of Option I. The most obvious advantage of this approach is that the Army would have forces ready to deploy to peace operations on fairly short notice. In addition, the turbulence that now occurs when Army units need to deploy to peace operations would decline for both deploying and nondeploying units. For their part, soldiers would have the benefit of increased predictability: those in the on-call units would know that they might have to deploy at any time in the next six months. Another advantage of this option would be improved training for peace operations. Since units in this cycle would be more likely to be sent to such operations, their training could focus on the tasks needed for that mission. Finally, since this option would not add forces to the Army or require any change in equipment, its costs would be negligible.

Disadvantages of Option I. Army divisions typically have command and support elements that brigades do not. Thus, if brigades deployed to peace operations, they might need to take along some of their divisions' support assets. That problem reflects a larger drawback of this option: since the number of units and the size of the Army would not change, the personnel to increase the readiness of the on-call units would have to come from other units. As a result, although the readiness of some units would increase, the readiness of others would inevitably decline. Another disadvantage is that if the units in this cycle concentrated their training on peace operations, their conventional warfighting skills could degrade. Those units might then be less ready if they were needed for a major theater war. In addition, personnel in the on-call units could be subject to frequent deployments, which could hurt their morale and retention.

Option II: Reorganize Existing Active Army Forces for Peace Operations

This option would reorganize four existing brigade-sized units specifically to deploy to peace operations. Unlike the rotating units in Option I, which would be ordinary combat brigades on call for contingencies, these brigades would tailor all of their training, equipment, and special capabilities for peace operations. Therefore, they would contain more support forces, civil affairs personnel, and military police than a traditional combat brigade, but they would also need enough armored equipment to protect themselves during peace enforcement missions. The brigades would be maintained at full strength since they would be expected to deploy on short notice. In addition, this option would create three standing task-force headquarters that would devote their full attention to peace operations. They would develop doctrine and recommended groups of forces and would command the forces that actually deployed to such operations.

Creating the new headquarters units would entail one-time costs of about $30 million. Operating the headquarters and the four brigades would add about $90 million per year to the Army's recurring costs.

Advantages of Option II. By creating specialized units for peace operations and keeping at least one of them fully ready at all times, this option would enhance the Army's preparedness to conduct such operations on short notice. In addition, having standing headquarters would ensure that the planning and execution skills needed for peace operations were practiced on a regular basis. This option would also benefit the remaining Army forces by allowing them to focus full time on preparing for conventional war without the distraction of peace operations.

Disadvantages of Option II. This alternative would have two main drawbacks. First, it would reduce the Army's overall capability for conventional war, since some units would not train for that as their primary mission. Second, as with Option I, the soldiers assigned to units designated for peace operations would probably have to deploy overseas often, which could cause morale and retention problems.

Option III: Convert Some Combat Units in the Active Army into Support Units

This alternative would convert one active-duty Army division entirely into support units. The division's existing support units would remain as they are, but its combat units, such as artillery and tank units, would be converted into the types of forces most needed for peace operations, such as civil affairs and military police units. That conversion would yield about 15,000 active-duty support troops, who could provide skills in high demand for peace operations and also help fill the Army's identified shortage of support forces.

Reorganizing and reequipping combat units to become support units would cost about $940 million, which could be spread over several years as the conversion took place. After that, this option would save the Army between $60 million and $210 million per year, primarily by avoiding the costs of calling up support units in the reserves for active duty.

Advantages of Option III. This approach would make the Army's active-duty force structure better suited to carry out peace operations without relying on the reserves. And by creating more high-demand support units in the active Army, it could reduce the rate of deployment for existing support units. This option would also enhance, to some extent, the Army's capability and readiness for conventional war. The Army has determined that it lacks enough support forces to fight two major theater wars; this alternative would alleviate some of that shortage.

Disadvantages of Option III. The greatest drawback of this option is that the United States would no longer have sufficient combat forces in the active Army to fight two nearly simultaneous major theater wars. Instead, the Army would have to rely on combat units in the reserves to take part in the second conflict. Those reserve units might not provide the same total combat capability as the active units they replaced. In addition, they would need more time to prepare for combat and thus would probably not be available as quickly as active units.

Option IV: Add Forces to the Active Army for Peace Operations

The final option would expand the size of the active-duty Army by adding 20,000 soldiers in units designed and designated for peace operations. Those additional personnel would be enough to create the four specialized brigades and three headquarters described in Option II (adding the brigades outright rather than reorganizing existing brigades). Two of the new units would be light infantry or military police brigades and two would be armored or mechanized infantry brigades. Each would also have a complement of the high-demand support units necessary for most peace operations. That force could probably handle the majority of peace operations, although it might need to be augmented from the rest of the Army in times of particularly heavy activity, when several large operations were occurring simultaneously.

The new units could be equipped mainly with weapons and vehicles that the Army is retiring from National Guard combat units that it plans to convert into support units. Thus, the one-time costs to equip the units would be negligible. Operating the new brigades and headquarters would cost the Army an extra $1.9 billion a year.

Advantages of Option IV. As with Option II, having forces trained and designated for peace operations would improve the Army's ability to conduct such operations. And as with Option III, adding some support units to the active component would let the Army reduce its reliance on reserve units during peacetime and avoid the potential problems associated with frequent call-ups of the reserves. The advantage unique to Option IV, however, is that adding new units for peace operations would give the Army enough forces to fight two major regional wars and conduct peace operations at the same time. This approach would thus allow existing units in both the active and reserve components to focus on their wartime mission, thereby improving the Army's readiness for conventional war as well as for peace operations.

Disadvantages of Option IV. The greatest drawback of this option is that it would add significant costs at a time when the defense budget may not increase substantially. Also, since the new brigades would be equipped and trained for peace operations, they would not be thoroughly trained for combat. Some observers could argue that forces that are obviously trained for combat are more intimidating to potential aggressors, thus making them more effective at keeping the peace.

Previous Page Table of Contents Next Page