In the course of the 20th century the United States Army established a long tradition of experimenting and adapting combat forces to face the ever changing challenges of modern war. During this period the Army, on average, conducted major force design reviews and experimentation almost every decade. Some of these initiatives were reactive, restructuring to meet imminent threats or immediate needs. Others were visionary, bold attempts to anticipate the nature of future war. Not all of these efforts were uniformly successful. They were all, however, significant. They tell an important story--the Army's unrelenting effort to modernize America's strategic land combat power.

This study focuses on the most important organizational development in the American Army, the evolution of the modern combat division. The concept of the modern division first emerged in the late nineteenth and early twentieth centuries. The division was envisioned to be a large self-contained organization of several thousand soldiers capable of conducting sustained tactical operations under a corps headquarters. In the United States the division became the basic unit for planning and conducting land battles and engagements. 1

This study reviews the Army's major division design initiatives from 1917 to the origins of the Experimental Force (EXFOR) in 1995. The Army conducted hundreds of studies and experiments on force design during this period. This study focuses specifically on the Army's senior leadership and the fundamental design changes they initiated, with special emphasis on the critical strategic factors influencing them in the conceptualization, experimentation and implementation of change.

This tradition of change offers insights into how America's Army can sustain the momentum of modernization into the 21st century. There is a consistent pattern of organizational behavior in the Army's history of change. In the course of the study the following themes emerge again and again.

Experimentation. The Army has become increasingly sophisticated in its approach to force design. On the whole, its investments in experimentation have proved relatively modest and cost effective. These efforts allowed senior Army leaders to flesh-out new concepts and served as powerful focal points for implementing broad organizational and institutional change.

None of the Army's design initiatives emerged from a blank sheet of paper. They were all products of both reflection and forward thinking. Designers attempted to preserve the tested elements of an existing design or adapt them to suit future operations. They also incorporated new features reflecting anticipated requirements. Innovation was usually evolutionary and incremental. Revolutionary radical changes were the exception and rarely implemented successfully.

Influence of Military Strategy. National military strategy profoundly influenced the process of force design. Army leaders have always viewed land force requirements through the prism of existing and potential threats to national security. Since World War II, design efforts have habitually focused on what was perceived to be the most dangerous threat--"high intensity" combat in Europe. On the other hand, the Army also attempted to develop organizations that were sufficiently flexible to conduct the full range of military operations in diverse environments.

Design Principles. The division structure continually dominated the attention of force designers. This organization has proved durable and versatile, adapting well to new tactics and technologies.

Constraints. Resource constraints played a significant role in influencing the design process.

Leadership. Uniformly, the role of the senior leadership was the single most important factor in the Army's ability to successfully develop, test and implement organizational innovation.

Despite its long history of innovation, the Army's process of change remains largely "ad hoc." Each generation of Army leadership has found itself recreating the process of organizational innovation to meet its unique needs. Critical leadership tasks included identifying the basic principles to guide the redesign effort, allocating resources, directing experimentation, constructively moderating debate and controversy and implementing change.

It requires visionary, energetic and insightful leadership to shape the patterns of change into a viable force. This is the lesson of the Army's past initiatives and experiments and the prelude to Americats next force--Army XXI.

Initiatives and Experiments 1917-1995

Gearing Up for the Great War - 1917. The evolution of the modern American division began in 1917. Although the Army formalized a division design in 1905, no active divisions existed when the United States entered World War I. 2 When war came, the War Departrnent formed and deployed the 1st Expeditionary Division (later redesignated the 1st Division) to serve as the nucleus of combat troops for the American Expeditionary Force (AEF).

The 1st Expeditionary Division's organization was based on a study conducted by the War Department's War College Division and heavily influenced by British and French force designs. The study's recommendations, published on May 10, 1917, called for a "square" division built around two brigades of two infantry regiments each and totaling 19,492 personnel. The designers believed this configuration would be the most flexible for trench warfare. The brigades could be quickly flip-flopped to maintain sustained troop strength at the front. 3

The acting Chief of Staff of the Army, Major General Tasker H. Bliss, approved the new organization, but declared that it would be provisional pending input from the AEF. Meanwhile, Major General John J. Pershing, Commander of the AEF, established the General Organization Project, jointly run by officers from a War Department military mission and the AEF staff, to prepare a detailed plan for the division organization.

Based on General Pershing's guidance, the team modified the division from a unit designed for trench warfare to a force that could conduct sustained, offensive action. The team planned to raise the division's offensive power by enlarging the organization, giving it enough combat power to both breakthrough an enemy's main line of resistance and continue the attack. After significant debate and controversy over the size of the new division, the project recommended a combined arms force of 28,105 men, twice as large as any European division (appendix C-1). 4

In the fall of 1917, the Army adopted the General Organization Project's design and General Pershing reorganized and trained the 1st Division as a model for the rest of the AEF. The division became the Army's first modern experimental force. General Pershing hand picked the division's command team and assigned them responsibility for experimentation and refining warfighting concepts. 5 As they trained, leaders were encouraged to submit "brief written reports of any concrete recommendations or suggestions on equipment, supply, organization or tactics." 6 When other American forces deployed into theater, they adopted the division's innovations, employing them effectively in combat operations in 1918.

After the war, the Army convened a series of boards to consider how to improve the division design for future operations. The trench warfare of World War I was thought to be an anomaly. Future combat would place much more emphasis on maneuver. General Pershing, in particular, called for a new model, believing the square division would prove "entirely too unwieldy" for future mobile warfare. 7 Final recommendations retained the square configuration but incorporated new systems such as tanks and aviation assets, refined the organization and streamlined the size by almost a third to 19,997. Chief of Staff General Peyton C. March approved the revisions on August 31, 1920. 8

Battling the Blitzkrieg -1935. Following World War I, twelve of the updated infantry and one cavalry division were retained in the active force. In ensuing years budget constraints left only a thin-boned skeleton of these organizations. When General Malin Craig became the Army Chief of Staff in 1935, he was greatly concerned about the state of the divisions and the long lead time required for improving military preparedness. General Craig cautioned that inadequate force structures were incapable of rapidly adapting to radical shifts in military strategy--a serious shortcoming in light of Europe's worsening political and military situation. America needed an efficient, modernized Army ready to be expanded through rapid mobilization. 9

Within the constraints of his meager resources, General Craig was determined to define the force's need for future warfare. On November 5, 1935, he directed a study to relook the division design. A select committee was formed on January 16, 1936 and on July 30 they recommended a "triangular" division design (eliminating the two brigade headquarters and building the division around three infantry regiments). This initiative put the United States in step with force reorganizationand modernization being considered by the major European powers. General Craig approved the concept for testing on February 5, 1937.10

The most critical consideration in the division redesign was flexibility. Flexibility was achieved by basing the organization on the "rule of three." At each echelon, from platoon to division, commanders had three forces at their disposal. One to provide a base of foe; one to maneuver and outflank the enemy, and a third to exploit success and act as a reserve. This organization was thought the most suitable for a highly fluid fast war of movement.11

The Army also believed the division would be more flexible if it was smaller, requiring less room to maneuver. Proposed troop strengths for the new division were as few as 10,000, though the Army eventually settled on a structure with a little over 15,000, slightly more than half the size of the World War I division (appendix C-2).12

In addition to enhancing flexibility, strategic factors that emerged as the United States entered World War II heavily influenced the size of the division. The Army needed a tremendous number of divisions to fight the coming global conflict. At the same time, there were definite limits on manpower and equipment procurement. Later, shipping assets to deploy forces also became a significant constraint. 13

In part, personnel savings in the division structure were achieved because planners assumed the divisions would be part of a larger force that could provide combat and logistical support. Additional units were to be pooled at echelons above corps. The corps would be a small command headquarters responsible for controlling the divisions and, as the tactical situation required, augmenting them with the additional assets allocated from the field army. This initiative would prove to be the most controversial aspect of the new design.

The 2d Infantry Division tested the triangular concept in 1937. The designers modified the design and a second test was conducted in 1939. The tests were described as "the most searching and thorough tests ever made" and as "realistic as was permitted by the conditions of peace and lack of funds and of modern equipment in quantity.'' 14 The tests were systematic with step-by-step evaluations of each design element and detailed findings and recommendations on everything from the frontages and firepower per unit to the turnaround time for ration trucks.

In 1939, as German forces began their blitzkrieg across Europe, the new Army Chief of Staff, General George C. Marshall, ordered that the triangular design be adopted for all infantry divisions. The first infantry divisions were reconfigured by January 1940. In addition, the Army retained the cavalry division and developed a variety of specialized forces including armored, motorized, light infantry, mountain and airborne divisions. Controversy surrounded both the requirement and organization of these units as senior leaders weighed the need for flexible general purpose forces versus specialized divisions.

In particular, the design of the armored force earned special attention. The armor design had to be carefully thought through. It came with a hefty price tag. Though an armored unit had less men than an infantry unit, the support requirements to put an entire force on wheels and tracks were enormous. Just the logistical effort required to deploy armor forces was impressive. Every tank sent to Europe contained 500 items that had to be unpacked, cleaned, mounted and checked. It took a minimum of 50 hours to get one tank ready for combat. Armor was a big investment. The Americans tried hard to get it right. 15

The requirements for the armored force differed significantly from the infantry division. Armored commands were to be exploitation forces, operating independently for extended periods. As a result, the armor design objectives called for greater flexibility and more organic capabilities.

The armor design eventually evolved into an armored division including two tank regiments and an armored infantry regiment. Two combat commands (CCA, CCB) were also included in the division. The addition of these headquarters allowed the division commander to task organize forces to a combat command for a specific tactical mission. For example, if the combat command had a mission that called for heavy close quarters combat, it might be composed of an equal mix of infantry and tank battalions. On the other hand, if the task was rapid exploitation, the command would be predominantly tank heavy with only minimal supporting arms.

During the war, the Army continued to modify the design, going through six major revisions. Based on combat experience, the need to conserve manpower, and further increase flexibility, designers eliminated the regiments, added a reserve combat command (CCR), increased the ratio of infantry to tanks and reduced the number of battalions. The division strength dropped from over 14,000 men to less than 11,000 (appendix C-3). 16

In 1942, Lieutenant General Lesley J. McNair assumed command of the Army Ground Forces (AGF). It was his responsibility to turn force designs into reality and field, train and deploy the divisions. Under General McNair's leadership, the Arrny eventually fielded 90 divisions. Even as the divisions trained and deployed, the AGFcontinued to modify designs based on the Louisiana Maneuvers, other stateside large scale field exercises, and battlefield lessons learned. 17

In the crucible of battle, the World War II divisions demonstrated great utility, though they weren't perfect. In particular, the concept of "pooling" assets and attaching them to the infantry divisions as needed proved less than optimum. The infantry divisions found that they always needed nondivisional tanks, artillery, engineers, antitank and antiaircraft guns to conduct combined arms warfare. These units usually wound up habitually associated with the divisions throughout the course of an operation.

Due to a shortage of resources and the conclusion that they had limited utility, other division designs such as the cavalry, light and motorized divisions were discarded during the war. Mountain and airborne divisions were employed in combat, but of all the specialized designs only the airborne division was retained after 1945. 18

After the war, the U.S. European Theater of Operations established boards to analyze combat and support operations. Committees recommended numerous adjustments to the designs based on wartime experience. 19 The Army implemented several of the recommended changes between 1948-1950. The modifications increased firepower and made organic units that had previously been assigned from pooled echelon above corps assets. The infantry division, for example, increased to almost 19,000 personnel (appendix C-4).

An Army for the Atomic Age - 1954. The post-war evolution of the division design was essentially a paper exercise. After hostilities ended, President Harry S. Truman directed a pell-mell two year demobilization that reduced the Army from 90 to 10 divisions. Between World War II and the outbreak of the Korean War, budgetary limits shrank ground forces to the point that they became hollow divisions, lacking the personnel, equipment and training required for full combat effectiveness. 20

By 1950, the National Security Council (NSC) concluded that the demobilization had gone too far. Formed in 1947 to advise the president on domestic and foreign security issues, the council recommended a strategy in NSC68 which called for "a substantial and rapid" increase in military muscle to help contain the Soviet
threat. 21 Though not initially implemented, NSC68 provided a blueprint for the conventional force buildup that occurred during the Korean War. The Army expanded to 20 divisions by 1953.

The Army's rapid growth during the Korean War still reflected America's preoccupation with the defense of Western Europe. While four divisions went to Korea, the United States added four divisions to Europe and increased the stateside units available as reinforcements.

The expansion of the Army was short-lived. In the wake of the conflict, President Dwight D. Eisenhower believed economic growth was the key to the United States's future national security. His "New Look" strategy made massive retaliation with atomic weapons the centerpiece of America's defense posture. Reliance on atomic weapons to deter conflict allowed for reduced spending on more expensive conventional forces. This, in turn, enabled the administration to address pressing economic concerns. 22

President Eisenhower envisioned only a limited role for the Army. "If you want to be coldly logical about it," he once commented," the money being spent for ground forces could be used to better advantage on new highways to facilitate the evacuation of large cities in case of enemy [atomic] attack." 23 At best the Army might be needed to restore order and police the cities after an atomic assault. The Army's restricted role in the new strategy made it a prime target for reduction. From 1953 to 1957 the Army's budget fell from $15 billion to $7.5 billion. Manpower decreased from 1.5 million to 998,000 and there was a plan to reduce to 14 active divisions by 1960. 24

The Army leadership struggled to adjust to the new national strategy and austere budget projections. In January 1954, at the direction of the Army Chief of Staff, General Matthew B. Ridgway, Army Field Forces was tasked to develop new organizational concepts.

On April 19, 1954, General Ridgway provided detailed guidance. He wanted designs to be more mobile and flexible. The division should exploit available new technology and be able to disperse to avoid the effects of atomic strikes. General Ridgway also directed that the new units should have more favorable combat capability-to-manpower ratios. Finally, he added that he wanted to begin reorganization in two years. 25 On June 9, 1954 Army Field Forces submitted proposals for infantry and armored divisions designed to fight on atomic battlefields. On July 21, General Ridgway approved the studies, though he had concerns and wanted further refinements. In particular, he wanted more conventional combat power in the designs.

Based on his guidance, in the fall of 1954 the Army Field Forces developed the Atomic Field Army (ATFA-1). The study analyzed the organization of 245 different types of units. The armored division retained its current organization with three combat commands, but was reduced by 2,700 personnel to about 12,000. The new infantry division also had three combat commands (eliminating the regimental organization). The division would have about 13,500 personnel, a reduction of almost 4,000 (appendix C-5). 26

In February 1955, the 47th Infantry Division (the test units were later reflagged under the 3d Infantry Division) and the 1st Armored Division tested the ATFA-1 designs in field exercises FOLLOW ME and BLUE BOLT. These were the first major Army-directed field experiments since testing the triangular division in 1939. Following the field trials, the Army Field Forces revised the ATFA-1 organizations and evaluated the adjustments during exercise SAGE BRUSH from November 1 to December 15, 1955.

Exercise SAGE BRUSH, conducted at Fort Polk, Louisiana, became the largest field trials held in the United States since World War II. It included 110,000 Army troops plus 40,000 Air Force personnel. The exercise scenario tested the divisions under conditions of simulated atomic war, covering 25 major areas and focusing on dispersion, communications and mobility. In the end the final test report did not recommend ATFA1, concluding the designs could not sustain high tempo, dispersed operations. Even before the tests had concluded, however, there were signs that senior leaders had soured on the concept of an Army designed to fight only in a general nuclear war. In April 1956 the Army officially closed the study. 27

Though the Army didn't adopt ATFA-1, the field tests showed that no experiment is a failure if it provides useful insights to its designers. Exercise SAGE BRUSH established a clear blueprint for the direction the Army wanted to go. The final test report concluded that some of the initiatives in the ATFA-1 organization showed promise. For example, the report called for an increased role for Army aviation, praising the sky cavalry (SKY CAV) concept that grouped air transport, aerial reconnaissance and air transportable ground reconnaissance under one headquarters. 28

The test also pointed towards additional requirements. The divisions needed an improved ability to disperse and mass quickly. In particular, they needed better cross country mobility and air transportability. In addition, more emphasis needed to be placed on tactical atomic weapons. These weapons could greatly increase the combat power of ground forces and were better suited to the defense of Western Europe. NATO allies were becoming increasingly skeptical that the United States would risk a general atomic war to defend Europe. Tactical atomic weapons offered a better alternative for deterring conflict.

While the ATFA-1 study was closing down, the experimental process continued with another effort that was being conducted simultaneously with the atomic army redesign. The Army Field Forces had determined that to develop a division that could fight on either an atomic or nonatomic battlefield required a separate analysis. In November 1954, General Ridgway commissioned the second study. This project was called "Doctrinal and Organizational Concepts for an Atomic-Non-Atomic Army During the Period 1960-1970;" short title the PENTANA Army. 29

In June 1955, General Maxwell D. Taylor succeeded General Ridgway as the Army Chief of Staff. He took immense personal interest in shaping the outcome of PENTANA. Based on his airborne experience in World War II and combat in the Korean War, General Taylor believed he had learned a great deal about the problems and potential of the most likely form of future combat-dispersed, nonlinear warfare. In 1954, while rebuilding the South Korean Army, he used a Korean division to study designs for this kind of war.

General Taylor concluded divisions should be able to disperse into small units capable of independent action and yet be able to swiftly concentrate. Dispersed operations would prevent units from becoming lucrative atomic targets. Quick concentration would allow the division to rapidly mass combat power. General Taylor eventually decided that five was the optimum number of subordinate units to implement these tactics. Shortly after becoming Chief of Staff, he outlined the concept to planners at the Continental Army Command (CONARC replaced the Army Field Forces on February 1, 1955). 30

By mid-December CONARC submitted its proposal for an airborne division that incorporated features from both PENTANA and ATFA-1. Rather than having brigades, regiments or battalions, the division consisted of five battle groups. The new formations were called battle groups because they were each supposed to be capable of fighting an independent, sustained battle. 31

Even before the new design was complete, General Taylor directed that the airborne division be reorganized along the lines he mapped out. The following April, the 101st Airborne Division at Fort Campbell, Kentucky was reconfigured into what came to be called the Pentomic division. 32

In large part General Taylor pushed for the Pentomic division because he believed the Army needed a dramatic, new concept to demonstrate its relevance to the modern battlefield and improve its ability to compete with the other services for limited modernization dollars. Later reflecting on the Pentomic effort, retired General William E. DePuy attributed the initiative "to the fact that the Army seemed left out, and the Army needed to sound and appear very modern, and Pentomic was thought to be one way to do that." 33 Even General Taylor acknowledged that to enhance the prestige of Army budgetary requests he had to create a "Madison Avenue adjective [Pentomic]" to describe the new division. Besides, "Nuclear weapons were the going thing," he concluded, "and, by including some in the division armament, the Army staked out its claim to a share in the nuclear arsenal," and with it, the defense budget. 34

The Pentomic design did justify demands for additional resources. The PENTANA study called for developing new weapons and equipment, as well as increasing manpower. In fact, the Army's semi-annual report for 1956 noted that even though the new division was smaller it "will not lessen the overall manpower needs." Personnel needs would increase because of the additional "manpower required for supplying and resupplying widely dispersed units." 35

By the end of the decade the Army was able to expand research and development, though most of the advances were in tactical atomic weapons. The Army couldn't escape the attraction of atomic weapons, the only technology that promised a tremendous increase in combat potential with limited manpower. The Army poured 43 percent of its fiscal year 1957 research and development budget into missiles and atomic warheads and projectiles. In contrast, less than 15 percent went to new vehicles, aircraft and artillery combined. 36 The imbalance in modernization meant that in practice the Army wasn't developing all the systems it needed to make the Pentomic concept work.

Meanwhile, in December 1955, CONARC completed the PENTANA study. PENTANA envisaged a universal, air transportable division of 8,600 men to replace existing divisions (appendix C-6). The only problem was the Army didn't have the money or the technology to implement the concept. In June 1956 General Taylor approved the PENTANA study as an objective for research and development, concluding, "PENTANA, as modified, should be put on the wall as an objective toward which the Army will progress. The gap will be filled by a series of evolutionary, modified versions." 37

General Taylor directed that the airborne, infantry and armor divisions be streamlined along the lines of the design. Though not as lean as PENTANA, the division designs incorporated many of its radical features. The new divisions, except for the armored force, were structured around five combat groups, smaller than regiments or brigades, but larger than battalions.

New Pentomic tables of organization and equipment (TOE) were developed for the existing divisions. The airborne force was organized under the Reorganization of the Airborne Division (ROTAD) TOE, initially published in August 1956. It provided for a strength of 11,486 men, down from 17,085. All men and equipment of an airborne division, except for the Honest John rocket unit, could be transported by air (appendix C-7). 38

The infantry units were organized under Reorganization of the Current Infantry Division (ROCID) TOE. It set unit strength at 13,748 men, a reduction of over 3,500 personnel. It was supposed to have lighter equipment and be as air-transportable as possible. The initial test TOE also had a single small brigade headquarters whose purpose was to provide command and control of attached elements as directed by the division commander and to act as an alternate division headquarters in the event of an emergency. The headquarters was never seriously utilized in either role, and when a revised TOE was completed in February 1960, the brigade was eliminated (appendix C-8).

The Reorganization of the Current Armored Division (ROCAD) TOE, approved in December 1956, only nominally adopted the Pentomic design. There were few changes, except to add Honest John rockets. Armored divisions retained their combat command structure, and unit strength was reduced by only 66 slots, to an authorization of 14,617 men (appendix C-9).

General Taylor directed that the 101st Airborne Division would conduct the first test the Pentomic force structure. During the winter of 1956-1957 the division conducted a series of exercises called troop test JUMP LIGHT at Fort Campbell, Kentucky with the Third US Army serving as the test director. The results of the test called for no major changes the Pentomic design. Meanwhile, the infantry and armored divisions were directed to conduct "self-evaluations." In total, the scope of the PENTOMIC evaluations were perfunctory when compared to the Army's other major force redesign experiments. The Pentomic design was the Army's least methodical force redesign effort. 39

Even as the Army began to overlay the Pentomic design over the divisions, there were concerns and sharp criticisms from among its senior commanders. For example, Major General Hamilton H. Howze, Commander of the 82d Airborne Division, flatly argued that the five-sided organization made no sense. Battle groups were not large enough to conduct a sustained attack or an aggressive defense. At the same time, the elimination of the battalion structure decreased flexibility; the battle group could not control and tactically deploy subordinate companies efficiently. In fact, the commander's span of control at all levels was too great given existing communications technology. To make matters worse, the division lacked sufficient support units and administrative staffs. Commanders had to rob "foxhole" strength from line units to support non-combat functions. Finally, the design created a professional development crisis. By removing the battalion echelon, it eliminated most of the key positions used to provide field grade officers (majors and lieutenant colonels) experience in operational assignments. 40

Table of Contents
Prelude to Army XXI, Part 2