The Doctrine of Military Change: How the US Army Evolves


Benjamin M. Jensen, Forging the Sword: Doctrinal Change in the U.S. Army (Stanford Security Studies, 2016).


The U.S. Army is often accused of being slow to change and unimaginative. Indeed, these are fairly predictable indictments that have dogged military organizations for centuries. Yet militaries do evolve over time to meet new challenges. The United States entered World War II with the Army’s horse-bound 26th Cavalry Regiment engaging Japanese tanks during the Philippines campaign. By the end of the war, the Army had evolved into a competent and robust mechanized force.

Military theorist J.F.C. Fuller referred to doctrine as “set of principles the Army uses to guide its actions in support of a national objectives.” The Department of Defense, in its quest to make any simple explanation unnecessarily cumbersome, defines doctrine as “fundamental principles by which the military forces or elements thereof guide their actions in support of national objectives.” To put it more simply than this, doctrine provides the lingua franca for military planners and thinkers to effectively discuss the military problems they face.

Since the conclusion of the Vietnam War, the U.S. Army has updated its main operational doctrine publication, Field Manual 3-0, seven times. These revisions included the introduction of Active Defense, Air-Land Battle, and Counterinsurgency doctrine, all of which were major doctrinal shifts designed to meet changing operational environments. So why, then, has the U.S. Army been able to readily make these changes successfully despite the many other examples of military organizations that have proven wholly unable to do so?

This is what Benjamin M. Jensen seeks to answer in his new book, Forging the Sword. Examining the numerous doctrinal changes the Army has undergone since 1975, he identifies two key institutional processes responsible. First, the presence of effective doctrinal incubators within the Army. Second, the persistent efforts of advocacy networks to support proposed changes coming from those same incubators.

Incubators are smaller subunits that exist outside of the existing military bureaucracy. Free to examine future trends and solutions, these incubators are able to devise novel solutions to problems instead of regurgitating current orthodoxy and giving it a fancy new name. The Army’s Training and Doctrine Command (TRADOC), long stigmatized as being slow and out-of-touch, has a rich history of creating these incubators to develop new doctrine.

Advocacy networks provide the intellectual forums for leaders across the Army to engage with these new proposed doctrines, critique and improve them, and provide buy-in from leaders at all levels of the organization. Professional associations, journals, and schoolhouses combine to form those networks to foster the spread of new ideas. Today publications such as War on the Rocks and The Strategy Bridge provide key new nodes within those same advocacy networks to engage with new emerging ideas that play outsized roles in the promulgation of new doctrine.

Air-Land Battle

The classic example showing the interplay of incubators and advocacy networks is the creation and adoption of the Air-Land Battle doctrine in the 1980s. Soviet armored units in Europe significantly outnumbered those of NATO. Worse, much of the Soviet advantage came from the huge numbers of follow-on forces that would flow into theater at the onset of conflict. Army planners realized that they would only succeed if they could disrupt the enemy’s rear areas,and consequently would require several key changes in the way the Army viewed the battlefield.

First, unit commanders would have to visualize operations much farther beyond the forward edge of battle than they had before. A division commander would conceivably be expected to influence events 70 kilometers beyond the forward line of troops. A corps commander saw that area of influence extending out to 150 kilometers. This was in turn accompanied by shorter time windows (at or below 96 hours for a corps headquarters) within which those commands would need to engage enemy targets. Second, Army formations would need to make greater use of precision fires and leverage the Air Force to “service” targets behind the lines. This meant U.S. Army ground units working closely with their counterparts in the Air Force, nominating enemy targets behind the forward line of troops to create tactical openings.

Though the Air-Land Battle doctrine was officially created and vetted within TRADOC, study groups at Fort Leavenworth and forward-stationed corps inside Europe began exploring how best to deal with repelling a massive Soviet ground attack in Europe. Once these ideas were proposed, they were then socialized for buy-in in the professional publications of mid-tier officers, such as Infantry and Armor magazine.

These same doctrinal developments both used and drove technological shifts. Military-wide studies identified the potential of precision munitions, creating the so-called “Assault Breaker” concept that so defined the second offset strategy. The demand for those munitions were spurred by other studies that articulated the Soviet threat that the Army would face in the 1980s.

Are Resources a Greater Determining Factor?

How far can incubators and advocacy networks carry a military? Take the example of the French Army. By the end of World War I, despite mid-war morale issues, the French Army was an innovative and aggressive force. Having developed innovative combined arms techniques, the French Army ended the war exhausted but far more capable and innovative than the elan-drunk formations that so disastrously faced German troops in the summer of 1914.

Why then was the French Army so unable to innovate during the interwar period? The French military viewed the importance of doctrine in ways similar and different than the U.S. military does now. The French interwar military argued that doctrine ensured “harmony” between individual military formations. This is similar to the idea that doctrine provides a common language (which in turn provides a degree of harmony), but is also far more restrictive in its conception. If the U.S. conception of doctrine is to provide a common language and series of concepts that can then be flexibly applied by subordinate commanders, the French concept of “harmony” evokes the image of a symphony, not a discourse. This contrasts with what emerged in the United States during the 80s, which could more readily be described as jazz, not a symphony.

For French military theorists of the period, this restrictive nature was a feature, not a bug. Much has been made of the French Army becoming overly fixated on the lessons learned from centrally controlled World War I battles that occurred in the final year of the war. Despite the concepts of mobile warfare by mechanized formations that had begun to emerge in Germany and (to a lesser extent) the United Kingdom, France remained mired largely in static defense.

Why did French theorists fixate on static defense? Voices inside the French Army advocated for a different approach. Charles de Gaulle, for instance, pushed for the adoption of a professional Army organized into mechanized formations. Marshal Philippe Pétain, on the other hand, wanted a large military composed largely of light infantry designed to fight in a defense-in-depth. Both De Gaulle’s and Pétain’s proposals were ignored, largely since they would have put key industrial locations of France, centered on the Franco-German border, directly into the conflict zone.

Borrowing Jensen’s framework, what incubators and advocacy networks existed within the French military? French Army doctrine was developed at the French War College (the École Superieure de Guerre), yet it was the French War College that rehashed the same doctrine of World War I. Advocacy networks also existed. De Gaulle clearly filled that role in his writings, but his ideas clashed dramatically with those of the War College.

Yet the story isn’t nearly as simple as that. Even if the French Army had possessed incubators and advocacy networks, it’s not clear to whom those newly incubated ideas would be advocated. The French High Command did not have clear lines of responsibility to judge new ideas. In a sense, then, the French military was almost too well-suited to doctrinal change. The decentralized system potentially allowed for the creation of incubators, yet no one was in a position to extract their ideas. As such, the French Army was stuck maintaining a “business as usual” approach to doctrine development.

In a larger sense, these failures were the result of larger problems faced by the French state during the interwar period. The privations suffered by the French population during the war, one that was fought largely on French soil, meant the French public expected their “years of agony” (as historian Eugenia Kiesling would term it) to be rewarded. The French military saw its draft period dropped from three years to one, which limited the French military’s ability to function as a coherent force. With soldiers in uniform for just a single year, the French military would in turn have to rely even more heavily on its reserve formations than it had in the past, since the short draft period meant that fewer soldiers were available for military service.

Further, this meant that any doctrine changes made by the French Army were made doubly difficult. In addition to the French High Command’s focus on making do with less, it also faced the prospect training units of reservists who might not be available for training for years at a time. If the High Command introduced too radical a change to the Army’s doctrine, the individual reserve units responsible for fleshing out standing divisions might arrive with a range of different training levels, having each trained on different skills required to enact different doctrines.

Are Structures or Resources Key?

What implications does this hold for the future of doctrine development in the United States Army? As Jensen has ably demonstrated, the Army possesses a robust structure in place to facilitate the development of new doctrine. But does that structure exist because of the relatively resource-rich budget environment that the Army has existed in? Though it has experienced cuts during the “peace dividend” at the conclusion of the Cold War and during sequestration, the U.S. Army has still enjoyed relatively advantageous budget conditions when compared to other NATO armies.

The Army itself actually provides examples of what happens when those resources aren’t nearly so abundant. During President Eisenhower’s New Look Policy during the 1950s, the Army found itself increasingly unable to afford major modernization programs and their associated doctrinal revisions. Under General Maxwell Taylor, the Army adopted the highly criticized “pentomic division” in part because it was unable to afford better alternatives. When General Taylor attempted to acquire new weapons and vehicles that would enable greater mobility and firepower on the nuclear battlefield, the Army found itself overruled, with Taylor being directed to purchase “newfangled” equipment by Secretary of Defense Charles Wilson. According to Taylor, the Army even began to adopt tactical nuclear weapons just to “stake out a claim to a share of the nuclear arsenal.”

This failure had major implications for the Army. As Andrew Bacevich argues, the new organization produced units far less trained and less capable. This is not surprising, given another motivation for this change was the declining budget prompting the Army to cut 100,000 soldiers. Conversely, Air-Land Battle enjoyed a period of relative budget plenty under the Reagan-era defense buildup.

Building organizational structures within the Army is vital for doctrinal innovation. But the Army cannot simply worry about advocacy within its formation. It must also understand the limited environment in which it exists and convey the reality of that environment to outside audiences across government and the national defense community. In the absence of such understanding, the Army will find itself attempting to build upon a foundation of sand, no matter how flexible its doctrine development process.


Luke O’Brien is an Army officer assigned to Aberdeen Proving Ground and is currently a Countering Weapons of Mass Destruction Graduate Fellow at National Defense University. He is also an associate member of the Military Writers Guild.  O’Brien’s views are his own, and do not represent those of the Department of Defense or the Army.  He can be found on Twitter as @luke_j_obrien.