Military operations associated with the global war on terrorism, especially the invasion and occupation of Iraq, have greatly increased the number and intensity of the Army's missions. With the exception of the 2nd Infantry Division (which is stationed in South Korea), all 10 combat divisions in the active component of the Army have been deployed at least once to Afghanistan or Iraq, and many have returned there or are scheduled to return. In addition, the Army has mobilized and deployed an increasing number of combat brigades from the National Guard; it now depends on the Guard's combat forces to a degree not seen in the more than 50 years since the Korean War. That dependence, combined with the Army's need to mobilize and deploy support units from the Army Reserve and National Guard, has required the Army to sustain a higher level of mobilization than the modern reserve system has experienced before.⁽¹⁾

As it conducts operations, the Department of Defense (DoD) is seeking to increase the speed with which Army forces can be deployed overseas. Concerns about speed arose with the lengthy deployment required for Operation Desert Storm in the early 1990s; those concerns arose again during the U.S. intervention in Kosovo in 1999 and, more recently, when difficulties arose in deploying the 4th Infantry Division to Operation Iraqi Freedom. Deployment speed is directly related to the size, weight, and flexibility of Army formations. Some observers believe that those formations are not agile enough to prosecute the sorts of military operations that are likely in the future.

Concerns about the pace of operations and about deployment speed have led numerous Members of Congress, DoD officials, and outside analysts to question whether the current size and composition of the Army is appropriate. In particular, they ask:

• Does the Army have enough forces, and the right kind of forces, to respond to contingencies that may arise other than the missions in Afghanistan and Iraq--that is, does the Army have sufficient ability to fight wars?
  
  
• Does the Army have enough forces, of the right kind, to sustain the occupation of Iraq or to conduct a similar operation requiring the stabilization and reconstruction of a sizable country--that is, does the Army have sufficient "peacekeeping" ability?
  
  
• Should the Army be structured to rely heavily on reserve personnel for the long periods that are associated with stabilization and reconstruction operations?
  
  
• Is the Army capable of responding to crises and deploying to distant theaters of operations quickly?

The concerns underlying those questions have led defense officials and lawmakers to take a number of actions in recent years. The Army's Chief of Staff, General Peter Schoomaker, has launched a reorganization plan--called "modularity"--that is intended to increase the number of combat units available to the Army while making those units more flexible, more self-contained, and faster to deploy. In addition, two of the Army's ongoing efforts--to introduce Stryker armored vehicles and eventually to replace the current mix of tanks and armored vehicles with families of light armored vehicles through the Future Combat Systems (FCS) program--are intended to increase the responsiveness and deployment speed of Army units. To help carry out the modularity plan, the Secretary of Defense has given the Army temporary authority to add up to 30,000 soldiers to the active component. Subsequently, in the 2005 defense authorization act, lawmakers authorized the Army to increase the permanent end strength of the active component by 20,000 personnel.

In addition, the Secretary of Defense has ordered all of the military services to find ways to reduce dependence on their reserve components. DoD has also adopted a new set of Joint Swiftness Goals that establish very challenging targets for how fast forces must be able to deploy to operations.

This study by the Congressional Budget Office (CBO) examines various ways in which the Army could be restructured to address the concerns outlined above. CBO's analysis compares the costs of alternative force structures as well as quantitative measures of their capability for warfighting, peacekeeping, reliance on the reserves, and deployment speed. The analysis points to several general conclusions about the possibilities for restructuring the Army:

• Alternatives that would significantly improve the capabilities measured by CBO would require more personnel and have higher costs. Within current budgetary and personnel constraints, there is only limited potential to increase the Army's warfighting and peacekeeping capabilities substantially, to trade one kind of capability for another, or to decrease the service's reliance on the reserves.
  
  
• The modularity initiative will boost the number of combat forces available to the Army by up to 5 percent. But it may require an additional 60,000 personnel to do so (or twice the temporarily authorized increase), and it will make the Army more reliant on reserve support units. Moreover, modularity is unlikely to lead to substantial improvements in deployment times.
  
  
• The number of support forces that the Army normally uses with major combat units means that even relatively small increases in combat units would require significant increases in personnel. The Army could boost the number of major combat units without adding many personnel by reducing the level of support provided to combat units. However, doing that would raise the level of risk in warfighting, according to present Army doctrine.
  
  
• In its current structure, the Army is dependent on reserve forces for conducting even relatively small operations.⁽²⁾ Eliminating that dependence so that the active Army could operate without extensive reserve mobilization would require either greatly increasing the size of the active Army or substantially lessening its combat power. However, the service could reduce the level of reserve mobilization needed to sustain peacekeeping operations by reallocating the types of support units that are located in the active and reserve components.
  
  
• Proposals to create dedicated "peacekeeping" formations in the Army would be unlikely to produce a sizable increase in the number of soldiers that the Army could deploy to peacekeeping operations. Such formations might have qualitative advantages, but CBO found that converting combat forces to peacekeeping forces would not significantly increase the number of soldiers that the Army could sustain in extended deployments.
  
  
• Proposals to field "medium-weight" formations equipped with Stryker vehicles would not improve deployment times substantially.
  
  
• Proposals to restructure the Army to employ fewer, smaller, lighter combat units equipped with advanced weaponry (such as the FCS) could improve deployment times slightly. However, those proposals would significantly decrease the number of soldiers that the Army could deploy to peacekeeping operations.
  
  
• Proposals to eliminate some layers of command structure (such as the corps level) would be unlikely to reduce the size of the Army or speed up deployment as long as the general types and numbers of support units included in those command levels were retained.
  
  
• The Army could improve deployment times substantially by investing in additional sealift assets (transport ships), prepositioning more equipment closer to potential theaters of operations, and making some organizational changes. Although such steps would entail up-front costs, they would be less expensive over the long run than the Army's current plans.

The Army's Force Structure Before Modularity

Before the Army began making changes as part of its modularity plan (described below), its force structure had been relatively stable since the mid-1990s. That structure was based around fielding 10 active divisions, eight National Guard divisions, and numerous separate brigades (see Summary Table 1). When combat divisions or brigades are deployed to a major operation, they require significant numbers of support units that perform various functions, such as units for logistics, field hospitals, communications networks, construction engineers, additional artillery, and many others. Those support units are generally grouped under higher-level commands, such as the corps (intended to support two to five divisions) or the theater (intended to support one or more corps). The Army also has a large number of personnel who are not assigned to combat or support units. They include trainees, "transients" (people in transit between assignments), and personnel assigned to administrative units.

Summary Table 1.

The Army's combat units are categorized by how they are equipped and trained to fight. "Heavy" units are equipped with tanks and other armored vehicles; they are intended for combat against other armored forces in relatively open terrain. "Light" units are various types of infantry without armored vehicles, including airborne and air assault units, such as the 82nd Airborne Division. "Medium" units are relatively new and are equipped with the Army's new Stryker light armored vehicle. The Army introduced medium forces in the past few years in part because of concerns about the deployability of heavy forces, which require significant lift assets (transport planes and ships) to move, and about the firepower of light forces, which are not equipped for the most intense combat.

Since the 1970s, the Army has integrated its active and reserve components under what is known as the Total Force Policy. The Army's implementation of that policy has involved concentrating combat units in the active component and units that support combat units in the reserve component. Consistent with that policy, the Army Reserve does not contain any combat units but instead is organized entirely to support units in the active component. The Army National Guard includes eight combat divisions. In general, the Army does not plan to deploy those divisions to combat theaters; instead, they are given missions such as homeland defense or forming part of the strategic reserve. As such, the Army does not field support units for most of those divisions. The rest of the National Guard consists of separate combat brigades, which the Army does plan to deploy to combat theaters, and support units, which are intended to support either the separate Guard brigades or active units. The result of that division of responsibility is that combat units in the active Army depend heavily on support units in the reserves, and it is extremely difficult for the Army to engage in any major operation without mobilizing reserve personnel.

In CBO's analysis, active and National Guard combat brigades for which the Army has a full set of support units are referred to as "supported brigades." National Guard combat brigades for which the Army does not have a full set of support units are referred to as "unsupported brigades." All brigades are considered either supported or unsupported.
 

Planned Changes to the Army's Force Structure

In February 2004, the Chief of Staff of the Army announced a plan to reorganize the Army's forces into a larger number of smaller, more "modular" combat brigades. That plan envisions increasing the number of combat brigades in the active Army from 33 to 43 (and possibly to 48, pending future decisions) while reducing the number of combat brigades in the National Guard from 36 to 34. Each of the new modular brigades would have one-third fewer subordinate combat units than traditional brigades do but would have more support units, thus theoretically allowing the brigades to be deployed in a more independent manner. To establish the new brigades, the Secretary of Defense has given the Army authorization for up to 30,000 additional soldiers. Currently, that authorization is only temporary, since the Army intends to find other areas where it can reduce the number of required personnel by an equivalent amount. In 2004, the Army began the process of reorganizing units and adding the brigades.⁽³⁾

Besides reorganizing its forces, the Army is planning to reequip them by replacing most of its current ground combat equipment with the Future Combat Systems. According to the Army, the FCS will include a network of sensors, munitions, and communication links that would enable a force of medium-weight armored vehicles to fight with the power and survivability of today's heavy forces. When the FCS is fully fielded, the Army expects units equipped with it to require fewer personnel and deploy more quickly than current units do. The Army expects to equip existing units with some FCS sensors and networks fairly soon, but it anticipates that fully equipping all combat brigades with the FCS will take several decades. CBO estimates that once the FCS program enters full production, it will cost about $7 billion to $9 billion per year to procure until the Army is fully equipped.
 

Alternatives for Restructuring the Army

The Army could respond in many different ways to the concerns that have been raised about its ability to fight wars, its peacekeeping capability, its dependence on the reserves, and its deployment speed. This analysis examines eight alternative approaches to reorganization that would address those concerns (see Summary Table 2). Some of the alternatives would alter the size of the Army; others would change the distribution of units between the active and reserve components or create new types of units. The options incorporate features of proposals made by various participants in the public debate. Those features illustrate some of the important trade-offs and constraints involved in restructuring the Army.

Summary Table 2.

None of the alternatives are based on the Army's modularity plan because that plan has not been developed in enough detail to allow CBO to analyze it fully. To date, the Army has not announced the number or type of support units that modularity will require, nor has it incorporated modularity into its more detailed budget plans, such as the Future Years Defense Program (FYDP).⁽⁴⁾ For that reason, CBO's analysis compares each alternative with the Army's preexisting structure (before the changes being made as part of the modularity reorganization). However, the analysis does look at the potential implications of modularity for each alternative. (In addition, Appendix B presents more information about modularity and some of the issues it may involve.)

Because the details of the Army's modularity plan are still fluid, CBO estimated the costs of the alternatives relative not to that plan but to the costs of forces in DoD's 2005 FYDP and in CBO's long-term projection of the implications of that program.⁽⁵⁾ CBO divided the estimate for each option into investment costs, which include the costs of developing and purchasing equipment for units, and operation and support (O&S) costs, which include compensation for military personnel and the peacetime costs of units' day-to-day operations. For each option, CBO also estimated the annually recurring O&S costs that would continue after the projection period. If the Army retained its current force structure, its investment costs would total $605 billion through 2022, and its O&S costs would total $1,488 billion. (All estimates are in 2006 dollars.) By the end of that period, annual O&S costs would amount to about $100 billion. The alternatives in this analysis would range from costing an additional $333 billion over the 2006-2022 period to saving $314 billion (see Summary Table 3).

Summary Table 3.

CBO also developed measures to compare each alternative's force structure with the Army's premodular force structure in several areas besides cost:

• The total number of combat brigades in the Army and the number of fully supported combat brigades that would be available for warfighting;
  
  
• The total number of personnel that could be sustained overseas for extended peacekeeping deployments;
  
  
• The number of reserve personnel who would have to be mobilized to support extended peacekeeping deployments; and
  
  
• The time that the Army would need to deploy a brigade, a division, a corps, or a full theater's worth of forces to a combination of distant theaters.

Those measures are intended to permit a quantitative comparison between alternatives. They do not, and cannot, encompass all of the possible effects of reorganizing the Army. Proponents of particular changes to the Army might argue that qualitative effects are the most important elements of their proposals. However, CBO's analysis focuses on quantitative measures and does not incorporate those effects.

Alternatives That Would Increase the Size of the Army

The first two options that CBO analyzed illustrate the effects of expanding the Army. Many observers believe that expansion is necessary to improve the Army's ability to deal with missions like the occupation of Iraq, to respond to other threats that may arise during that occupation, or to reduce stresses on the reserve component. Alternatives 1A and 1B would both expand the Army by two divisions, but in different ways.

Alternative 1A--Add Two Active Divisions. This option would increase the size of the Army's combat forces by adding two divisions, with a total of six combat brigades, to the active component. CBO examined this option because it is a relatively common proposal in the public debate, especially among observers who worry that current missions are overstretching the Army.

One of the new divisions would be a heavy division, and the other would be a light division. Together, they would require a total of about 29,000 additional active personnel. This alternative would also add the full range of support units associated with two divisions (including corps support groups, corps artillery brigades, and so forth). Those support forces would include active and reserve units--preserving the Army's current distribution of support units between the active and reserve components--and would require another 12,000 active and 18,000 reserve personnel. In addition, this option would increase the number of personnel assigned to the Army's administrative units and the size of its account for individuals not assigned to units by about 15,000 active and 3,000 reserve personnel to allow for the greater administrative workload and for an increase in the number of trainees, transients, and students. In all, those changes would require the Army to add about 78,000 personnel--57,000 active and 21,000 reserve (see Summary Table 3).

Outfitting the new divisions with current equipment and continuing to modernize them thereafter would cost a total of $31 billion over the 2006-2022 period. Operating and supporting those units would cost another $95 billion over that period and almost $7 billion a year after 2022.

Creating two new divisions would give the Army more combat brigades for fighting wars and would improve its ability to sustain long deployments. If the additional divisions were structured like current forces, they would not be any easier or harder to deploy.

Increasing the size of the Army would not directly reduce the level of reserve mobilization needed to fight wars or sustain deployments, since the majority of the Army's support units would remain in the reserves, and the active component would still need to mobilize those units for nearly all operations. Indirectly, however, a larger Army would be capable of maintaining a higher level of sustained deployments before it needed to mobilize reserve combat units to augment active forces. (Summary Table 3 shows an increase in reserve mobilization under this alternative because with a larger active force, the number of reserve personnel mobilized would rise if that entire force was committed to deployments.)

Alternative 1B--Add Two Active Divisions by Reducing Support Forces. Like the previous option, this alternative would add two divisions to the active component, but it would do so without appreciably increasing the overall size of the Army. Instead, it would make room for additional combat units by eliminating some support units from the Army's current structure. CBO examined this alternative because some analysts have suggested that the Army has more support units than it needs and could shift personnel to more-useful combat units without unduly damaging its ability to wage wars.

This alternative would create room for two active divisions by eliminating all short-range air-defense (SHORAD) units and some corps-level artillery units from the Army's force structure. CBO chose those support units for elimination because some observers have suggested they may not be necessary and because the Army has taken similar steps as part of its current reorganization plans. In addition, this option would do away with the logistical support units associated with the eliminated SHORAD and field artillery units, thus freeing up a total of 50,000 personnel to be used in the two new divisions. With fewer support units, divisions would be slightly smaller in this option than in the previous alternative. Even so, 50,000 troops would not be quite enough to fully staff the new divisions and their support units, so this option would require increasing the size of the active Army by 6,000 personnel (see Summary Table 3).

Outfitting the new divisions with current equipment and continuing to modernize them thereafter would cost slightly more than in Alternative 1A: a total of $34 billion through 2022.⁽⁶⁾ However, because this option would eliminate various support units, it would increase the Army's operation and support costs to a far smaller extent than the previous option would: by $20 billion rather than $95 billion over the 2006-2022 period. After that, this alternative would add a little more than $1 billion annually to O&S costs, compared with nearly $7 billion under Alternative 1A.

Adding two divisions to the Army by reducing SHORAD and field artillery units would have almost the same advantages as simply increasing the size of the Army under the previous alternative. But it would carry some additional risks, since units would have less artillery support and no short-range air-defense capability. With slightly smaller divisions that would need fewer support units, this option would produce a smaller increase in the number of peacekeepers that the Army could deploy than would be the case in Alternative 1A. Deployment times would be faster, however.

Alternatives That Would Reduce Dependence on the Reserve Component

The next two approaches that CBO analyzed are intended to show how the Army could reduce its dependence on mobilizing reserve units to support active combat units. Both Alternatives 2 and 3 would effectively eliminate the need to deploy reserve units overseas to support active units in extended peacekeeping missions; Alternative 3 would also eliminate the need to deploy reserve units to support active units in major combat operations.

Implementing those alternatives, however, would not necessarily mean that no reserve personnel would be mobilized for peacekeeping or major combat operations, for two reasons. First, the Army's overall capability to maintain extended deployments includes the personnel that would be available if the Army mobilized National Guard combat forces (and reserve support units for those combat forces). Presumably, the Army would generally attempt to carry out its missions by using active forces first, but some operations or combinations of operations could require enough troops that the Army would also mobilize National Guard combat forces--as it is now doing in Iraq. Using National Guard forces in that way would, of course, require mobilizing reserve personnel.

Second, the Army generally mobilizes some reserve personnel to fill in at the home bases of active units that have been deployed. That practice, known as "backfill," allows bases to keep functioning normally when their units are deployed (for example, reserve personnel might be called up to provide guards for the bases). Although the number of reserve personnel mobilized to provide backfill is smaller than the number of active personnel who have been deployed, that practice can still lead to a significant level of reserve mobilization if the active force is heavily committed.

Alternative 2--Reallocate Support Forces Between the Active and Reserve Components. Responding to criticism of the Army's practice of relying on extensive and extended reserve mobilizations for peacekeeping missions and the occupation of Iraq, this option would shift support units between the active and reserve components. Units that are especially necessary for long peacekeeping operations (such as military police) would be moved from the reserve component to the active component, and units that are not essential for those operations (such as artillery units equipped with missile launchers) would be moved from the active Army to the reserves. As a result, virtually all of the support units needed for peacekeeping would be in the active component, and virtually all of the support units needed for warfighting would be in the reserve component.

All told, the number of personnel in combat and support units in the active Army would increase by 20,000 under this option, and the number of personnel in such units in the reserves would shrink by an equal amount. With individuals in administrative units, in training, or between assignments included, this alternative would increase the active Army by a total of 28,000 people and decrease the reserve component by 24,000 people (see Summary Table 3).

Those changes would greatly reduce the level of reserve mobilization necessary to conduct extended peacekeeping operations. The Army would still depend heavily on support units in the reserves for fighting wars and providing backfill for deployed active forces, but unless National Guard combat units were mobilized and deployed, peacekeeping operations would require far less sustained reserve mobilization in peacetime.

This option would not alter the Army's investment costs over the 2006-2022 period because it would shift units rather than create or eliminate them. However, the increased number of active-duty personnel would raise operation and support costs by a total of $27 billion through 2022 and by $2 billion per year thereafter.

Reallocating the Army's support forces between the active and reserve components would not affect the service's ability to fight wars because the Army would still have access to all of the combat divisions and support units that it has now. Similarly, such a reallocation would have only a minimal effect on the Army's ability to support long deployments.

This alternative would not affect deployment times directly, since the same equipment would have to be transported whether a particular unit was in the active or reserve component. This option might affect deployment times indirectly, however, because many types of support units (such as artillery units with missile launchers) would exist only in the reserves, and reserve units typically require at least a month for mobilization. However, that situation also exists for some types of units, such as civil affairs units, under the Army's current structure.

Alternative 3--Eliminate the Army's Dependence on Reserve Support Units by Increasing the Size of the Active Component. This option would eliminate the Army's reliance on support units in the reserve component by adding enough personnel to the active Army to create support units for all 10 of its divisions. The option is included in this analysis because it illustrates the full cost associated with ending the Army's current dependence on the reserves to support major deployments.

Besides creating new support units in the active component, this alternative would turn one of the Army's four corps, which is now composed almost entirely of reserve units, into a fully active corps; provide an active armored cavalry regiment (ACR) for each corps; and shift all of the Army's reserve special forces groups into the active component. To create the full set of support units needed for the four corps, 10 divisions, and 35 combat brigades that would be in the active Army under this alternative, an additional 312,000 personnel would be necessary. The reserve component could shrink by 260,000 personnel because it would no longer have to support active combat forces (see Summary Table 3).

The Army's investment costs would not change under this option because, for all of the support units created in the active component, identical units would be eliminated from the reserves. However, this option would have a larger impact on operation and support costs than any other alternative that CBO examined, increasing those costs by a total of $333 billion through 2022 and by about $26 billion per year thereafter.

Increasing the size of the active Army to a level that would eliminate its dependence on reserve support units would not significantly affect the service's ability to fight wars, since the Army would have almost the same type and number of combat formations as it does now. That change would, however, improve the Army's ability to sustain peacekeeping operations. The number of soldiers the Army can keep on extended deployment is limited by the fact that, according to DoD policy, reserve personnel cannot be deployed as frequently as active personnel. In this option, transferring a corps, the ACRs, and the special forces groups to the active component would allow those units to rotate through deployments at the higher rate used for active personnel rather than the lower rate used for reserve personnel.

The main benefit of this alternative is that the Army would not need to deploy reserve units overseas for major combat operations or long deployments. Reserve personnel would still need to be mobilized to provide backfill for active forces that were deployed, but no reservists would need to be deployed themselves. In the case of a very large peacekeeping deployment--larger than the active Army's forces could sustain alone--the Army might need to mobilize and deploy National Guard combat troops (and support forces for those combat troops). But for any level of commitment less than that, reserve units would not need to be sent overseas.

Since this option would not alter the types of units in the Army, it would not directly change deployment times. However, because reserve units typically require at least a month for mobilization, the Army might be able to deploy faster in some circumstances since it would not have to wait for reserve units to mobilize.

A potential variation on this option would be to eliminate enough active combat forces that the active Army would have sufficient personnel to support all of its combat units--in other words, to hold the size of the active component constant rather than hold the number of active combat units constant, as in this option. Doing that would require the Army to cut a corps, four divisions, and an ACR from the active component. Although that change would eliminate the active Army's dependence on the reserves in the same way that increasing the size of the Army would, it would substantially reduce the number of forces available for warfighting and extended deployments.

Alternatives That Would Create New Types of Units

The rest of the options in this analysis would restructure the Army in ways that emphasize different types of units, in response to a variety of concerns and proposals. Alternative 4 reflects a proposal by the National Defense University to create special "stabilization and reconstruction" divisions dedicated to peacekeeping. Alternative 5 would implement the frequently cited ideas of retired Army Colonel Douglas MacGregor, who has proposed converting the Army into flexible, autonomous brigade-sized combat groups. Alternative 6 would improve deployment speed by changing the Army's organization to more closely resemble that of the Marine Corps. Finally, Alternative 7 reflects the ideas of some leading proponents of "military transformation" in an attempt to show, in concrete detail, what a transformational force might look like.

Alternative 4--Organize Stabilization and Reconstruction Divisions. Many observers have argued that the Army should improve its peacekeeping capabilities relative to its warfighting capabilities. In keeping with those arguments, this option would convert some of the Army's combat divisions into dedicated peacekeeping divisions, or what a study by the National Defense University calls stabilization and reconstruction (S&R) divisions.⁽⁷⁾

In this alternative, the Army would eliminate two active combat divisions (one heavy division and one light infantry division) along with their associated support units. It would use the personnel freed up to organize five S&R divisions, four in the active component and one in the reserve component. Those S&R divisions would include military police, engineer, medical, civil affairs, and psychological operations units--which have been in great demand for peacekeeping operations--as well as a single medium-weight Stryker brigade. Overall, the number of personnel freed up by eliminating the combat divisions and their support units would be larger than the S&R divisions would require, which means that the Army would need 2,000 fewer active personnel and 9,000 fewer reserve personnel (see Summary Table 3).

Those changes would decrease the Army's total investment costs by almost $14 billion over the 2006-2022 period--both because of the smaller number of combat divisions that the Army would need to modernize and because of a reduced emphasis on high-technology weapons intended for conventional warfighting. The changes would also save $18 billion in operation and support costs through 2022 and $1 billion annually thereafter.

This alternative would reduce the Army's ability to fight wars because the service would have six fewer combat brigades available for contingency operations. In addition, the option would yield only a small increase in the total number of personnel that the Army could sustain on extended deployments, because the number of soldiers in the new S&R divisions would be roughly the same as the number in forces used for peacekeeping operations today. (The small increase would result from converting some units that are intended to support high-intensity combat to units better suited for peacekeeping.) Qualitatively, the mix of soldiers in each S&R division might be superior to the Army's current combat forces for peacekeeping, given their specialties and the historical demand for those types of units in peacekeeping missions. But CBO is unable to assess that potential superiority quantitatively.

This option would yield a slight decline in the level of reserve mobilization needed to sustain extended deployments because each active S&R division could be deployed without the reserve support units associated with combat divisions. That reduction would be lessened, however, if the Army needed to mobilize and deploy the S&R division in the reserve component.

Since S&R divisions are not intended for major combat operations, they would most likely not be deployed to fight a war. Thus, their creation would not affect the speed with which the Army could deploy its combat forces.

Alternative 5--Convert to a Brigade-Based Army. This option would restructure the Army in the manner suggested by retired Army Colonel Douglas MacGregor: eliminating higher-level command structures and organizing the Army's forces into a number of autonomous brigade-sized combat groups.⁽⁸⁾ Some elements of MacGregor's proposals are similar to the Army's currently planned modularity reorganization.

This option would eliminate divisions, corps, and theaters (and the traditional support structures associated with them) and create a set of large, semiautonomous brigade-sized combat groups in the active component. As in MacGregor's proposals, it would create a total of 25 combat groups in the active force and four in the reserves. The traditional forms of support provided by higher-echelon units would instead be provided by a mix of support groups, including aviation, artillery, air-and-missile-defense, surveillance, reconnaissance, engineering, logistics, and other types of units. This option would reduce the total number of combat brigades available to the Army from 69 to 29, but all of them would be fully supported.⁽⁹⁾ Most of that reduction would come from eliminating almost all of the National Guard's combat forces.

This alternative was constructed to adhere as closely as possible to MacGregor's plan for restructuring the Army; as such, it differs from most of the other alternatives that CBO analyzed. It is the only option that does not use the Army's rules for allocating support units, does not include a theater level of command, and does not include significant combat forces in the reserve component. This alternative would not change the number of active personnel but would require 383,000 fewer reserve personnel (see Summary Table 3).

In keeping with MacGregor's intent to improve the combat power of heavy forces as they are now equipped, this option would significantly alter the Army's investment plans. It would terminate the Future Combat Systems program (which is intended to replace current heavy platforms) while continuing various initiatives to rebuild, remanufacture, and upgrade the Army's heavy equipment. Those changes, combined with the smaller number of brigades that would need to be modernized under this option, would decrease the Army's investment costs by a total of $176 billion through 2022. They would also save $138 billion in O&S costs over the projection period and $10 billion per year thereafter.

By reducing the number of combat troops in the Army and emphasizing support units that would not be useful in peacekeeping (such as aviation or artillery strike groups), this option would leave the Army much less able to sustain extended deployments. However, because those combat troops would not depend on reserve support units, the forces that the active Army could sustain in peacekeeping operations would not require significant levels of reserve mobilization.

MacGregor suggests that an Army with only 25 active combat brigades, structured as he proposes, would be better able than the current force to deploy quickly and engage in fast-moving operations that would overwhelm conventional enemies. Based on CBO's assumptions about what a corps- or theater-sized force would look like in an Army modeled on MacGregor's concepts, this alternative would improve deployment times by more than one-and-a-half months (from three-and-a-half months to less than two months) for a theater-sized force. That improvement would be achieved both by the smaller force that would be deployed (just 60 percent of the brigades used for current forces) and by the reduced number of support units associated with each combat group (compared with an equivalently sized force composed of current units).

That improvement, however, would occur only if it proved feasible to engage in sustained combat operations with substantially lower levels of support than are used in today's Army. The improvement would also depend on the feasibility of eliminating the theater level of command, which performs a number of functions (such as seaport operations) that are important to other services operating in a theater. In that case, the other services might need to increase the size of their forces to compensate for the lack of support from the Army.

Because this alternative would greatly reduce the need for personnel in the reserve component, a number of variations on this option could be constructed that would restore the theater level of command or permit a larger number of National Guard combat units. Making such changes would reduce the savings from this option as well as some of the improvement in deployment speed, but it would increase the Army's overall ability to fight wars and sustain extended deployments.

Alternative 6--Convert to an Expeditionary Army. This alternative illustrates how the Army might be able to improve its deployment speed by adopting some organizational structures and practices used by the Marine Corps. This option would eliminate the corps as a command structure, reorganize the Army into a series of expeditionary forces (similar to Marine expeditionary forces), and purchase more sealift ships as well as additional sets of equipment that would be prepositioned on ships near potential areas of conflict.

In this alternative, each Army expeditionary force would consist of a division with four combat brigades (as currently sized and structured), an expanded aviation group, and a support group with logistics, communications, and other support units.⁽¹⁰⁾ Each expeditionary force would have one more combat brigade and slightly more personnel than a current division and its full set of combat and support units (43,000 people versus 39,000). In this option, the active Army would contain five heavy expeditionary forces and four light expeditionary forces. The reserve component would have four heavy and two light expeditionary forces and would retain 10 of the National Guard's current separate brigades. This option would also provide a full set of support units for all National Guard combat forces. In total, those changes would require 21,000 additional active personnel and 20,000 additional reserve personnel (see Summary Table 3).

To provide more sealift and prepositioned equipment, CBO developed a very different investment program for this alternative than the Army currently envisions. This option would terminate the Future Combat Systems program (which has been developed, in part, to improve deployment speed) and would replace it with various programs to rebuild, remanufacture, and upgrade the Army's current heavy equipment. The resulting investment program would be more expensive than the one in the previous alternative, both because this option would result in a larger heavy force and because it would have the Army procure several additional sets of equipment to preposition on ships. The Army would also buy 20 more large, medium-speed roll-on/roll-off ships (LMSRs) to transport equipment and to establish new flotillas of prepositioned equipment in the Mediterranean Sea and the Pacific Ocean.

This option would decrease the Army's investment costs by $87 billion over the 2006-2022 period, primarily from ending the FCS program. It would add $9 billion to the costs of the National Defense Sealift Fund, for a net savings of $79 billion over the projection period. This alternative would also increase O&S costs by a total of $45 billion through 2022 and by just over $3 billion annually after that period.

Converting to an expeditionary Army would produce a small positive change in the number of brigades available to the Army for fighting wars. It would increase the total number of combat brigades available by one, but it would better support the remaining National Guard combat formations, thus raising the number of fully supported combat brigades by 15. This option would also improve the Army's ability to sustain extended deployments and would slightly change the level of reserve mobilization needed to support those deployments.

The major advantage of switching to an expeditionary Army is that it would greatly reduce deployment times for large forces, such as a corps or theater. At the theater level, deployment times would decline from the current three-and-a-half months to less than two months. That improvement would result from the increased number of LMSRs, the additional flotillas of prepositioned materiel (which arrive in a theater sooner than materiel from the continental United States would), the reduced levels of support units, and the elimination of units associated with the corps. That last effect is relevant because deploying a corps to support and control multiple divisions requires about as much lift as each division does. For that reason, deploying three expeditionary forces (with 12 combat brigades) would actually require less lift than a current corps (with 10 combat brigades) does.

Alternative 7--Convert to a Transformational Army. The final alternative that CBO analyzed attempts to illustrate the type of force that many defense experts, such as DoD's former Director of Force Transformation, Arthur Cebrowski, have suggested would be "transformational"--that is, would take full advantage of recent advances in communications networks, precision-guided munitions, and sensors. Such experts typically stress the virtues of small, light ground formations that can be deployed rapidly and that depend on long-range, precision firepower instead of their own weaponry for effectiveness.

Under this alternative, the Army would have fewer divisions (although the corps structure would remain), and the mix of divisions would be shifted to lighter forces and special forces groups. Specifically, the active Army would consist of two heavy, two air assault, and two light infantry divisions. The National Guard would have a similar structure, with four heavy and two light infantry divisions (as well as its current separate brigades). Each division would receive significantly more attack and reconnaissance helicopters, cannon artillery, and missile-launcher artillery than current divisions have. In addition, some support units would be shifted between the active and reserve components. Overall, that restructured force would require 115,000 fewer active personnel than the Army currently has (see Summary Table 3).

Even with the emphasis on high-technology weapons, this option would lower the Army's investment costs by a total of $24 billion through 2022 because of the reduced number of combat divisions that the Army would need to modernize. In addition, that smaller force would cost $166 billion less to operate and support over the 2006-2022 period than the currently planned force and $12 billion less per year thereafter.

Supporters of military transformation argue that for a combat force equipped with modern communications, sensors, and precision munitions, size is not a good measure of fighting ability. In their view, military capability is more closely related to the ability of a force to identify and destroy targets (requiring superior intelligence and precision) than to the overall size of the force. Some supporters would even argue that smaller forces may be superior to larger forces because they are faster to deploy, more capable of surprising the enemy, and better able to disperse. This option would reduce the total number of available combat brigades by 14 (or about 20 percent), but if supporters' claims for improved warfighting ability are true, the Army might be capable of engaging in more simultaneous conflicts. However, CBO cannot assess such claims about the qualitative improvement that a transformational Army might provide.

Since the overall Army would be much smaller under this option than it is today, its ability to keep large numbers of personnel deployed for extended peacekeeping operations would be significantly reduced--by about 32,000 personnel--for two reasons. First, a smaller force cannot keep the same levels of personnel deployed as a larger force. Second, this option emphasizes long-range firepower, which is generally not useful for peacekeeping operations, so a smaller percentage of the Army's total support units would be suited to peacekeeping.

This option would not alter the degree to which the active Army relies on reserve units for support, so it would not change the level of reserve mobilization needed to sustain any given level of extended deployment (although if the Army was fully committed, reserve mobilization would rise). Since the Army would be smaller in this alternative, however, it would be more likely to need to mobilize and deploy National Guard combat units to sustain peacekeeping operations.

Supporters of military transformation claim that because a transformational Army would be able to fight wars with fewer but more-capable forces, it would be able to deploy to operations more quickly. CBO assessed that claim by assuming that corps- or theater-sized forces would be 40 percent smaller in this option than they are today. In that case, deployment times would decline by about 20 percent (or almost three weeks) for a theater-sized force. The reduction in deployment time is not as large as the reduction in size because with the emphasis on long-range firepower, each division would actually require more support units than the current force does. Artillery units, in particular, require significant logistical support, so the focus on long-range firepower in this option largely offsets the benefits of a smaller force. As a result, a theater-sized force that had 60 percent of the combat brigades used for current forces would require about 70 percent of the lift needed for current forces.