Dupuy’s Verities: The Inefficiency of Combat

The “Mud March” of the Union Army of the Potomac, January 1863.

The twelfth of Trevor Dupuy’s Timeless Verities of Combat is:

Combat activities are always slower, less productive, and less efficient than anticipated.

From Understanding War (1987):

This is the phenomenon that Clausewitz called “friction in war.” Friction is largely due to the disruptive, suppressive, and dispersal effects of firepower upon an aggregation of people. This pace of actual combat operations will be much slower than the progress of field tests and training exercises, even highly realistic ones. Tests and exercises are not truly realistic portrayals of combat, because they lack the element of fear in a lethal environment, present only in real combat. Allowances must be made in planning and execution for the effects of friction, including mistakes, breakdowns, and confusion.

While Clausewitz asserted that the effects of friction on the battlefield could not be measured because they were largely due to chance, Dupuy believed that its influence could, in fact, be gauged and quantified. He identified at least two distinct combat phenomena he thought reflected measurable effects of friction: the differences in casualty rates between large and small sized forces, and diminishing returns from adding extra combat power beyond a certain point in battle. He also believed much more research would be necessary to fully understand and account for this.

Dupuy was skeptical of the accuracy of combat models that failed to account for this interaction between operational and human factors on the battlefield. He was particularly doubtful about approaches that started by calculating the outcomes of combat between individual small-sized units or weapons platforms based on the Lanchester equations or “physics-based” estimates, then used these as inputs for brigade and division-level-battles, the results of which in turn were used as the basis for determining the consequences of theater-level campaigns. He thought that such models, known as “bottom up,” hierarchical, or aggregated concepts (and the prevailing approach to campaign combat modeling in the U.S.), would be incapable of accurately capturing and simulating the effects of friction.

Dupuy’s Verities: The Effects of Firepower in Combat

A German artillery barrage falling on Allied trenches, probably during the Second Battle of Ypres in 1915, during the First World War. [Wikimedia]

The eleventh of Trevor Dupuy’s Timeless Verities of Combat is:

Firepower kills, disrupts, suppresses, and causes dispersion.

From Understanding War (1987):

It is doubtful if any of the people who are today writing on the effect of technology on warfare would consciously disagree with this statement. Yet, many of them tend to ignore the impact of firepower on dispersion, and as a consequence they have come to believe that the more lethal the firepower, the more deaths, disruption, and suppression it will cause. In fact, as weapons have become more lethal intrinsically, their casualty-causing capability has either declined or remained about the same because of greater dispersion of targets. Personnel and tank loss rates of the 1973 Arab-Israeli War, for example, were quite similar to those of intensive battles of World War II and the casualty rates in both of these wars were less than in World War I. (p. 7)

Research and analysis of real-world historical combat data by Dupuy and TDI has identified at least four distinct combat effects of firepower: infliction of casualties (lethality), disruption, suppression, and dispersion. All of them were found to be heavily influenced—if not determined—by moral (human) factors.

Again, I have written extensively on this blog about Dupuy’s theory about the historical relationship between weapon lethality, dispersion on the battlefield, and historical decline in average daily combat casualty rates. TDI President Chris Lawrence has done further work on the subject as well.

TDI Friday Read: Lethality, Dispersion, And Mass On Future Battlefields

Human Factors In Warfare: Dispersion

Human Factors In Warfare: Suppression

There appears to be a fundamental difference in interpretation of the combat effects of firepower between Dupuy’s emphasis on the primacy of human factors and Defense Department models that account only for the “physics-based” casualty-inflicting capabilities of weapons systems. While U.S. Army combat doctrine accounts for the interaction of firepower and human behavior on the battlefield, it has no clear method for assessing or even fully identifying the effects of such factors on combat outcomes.

Human Factors In Warfare: Suppression

Images from a Finnish Army artillery salvo fired by towed 130mm howitzers during an exercise in 2013. [Puolustusvoimat – Försvarsmakten – The Finnish Defence Forces/YouTube]

[This piece was originally posted on 24 August 2017.]

According to Trevor Dupuy, “Suppression is perhaps the most obvious and most extensive manifestation of the impact of fear on the battlefield.” As he detailed in Understanding War: History and Theory of Combat (1987),

There is probably no obscurity of combat requiring clarification and understanding more urgently than that of suppression… Suppression usually is defined as the effect of fire (primarily artillery fire) upon the behavior of hostile personnel, reducing, limiting, or inhibiting their performance of combat duties. Suppression lasts as long as the fires continue and for some brief, indeterminate period thereafter. Suppression is the most important effect of artillery fire, contributing directly to the ability of the supported maneuver units to accomplish their missions while preventing the enemy units from accomplishing theirs. (p. 251)

Official US Army field artillery doctrine makes a distinction between “suppression” and “neutralization.” Suppression is defined to be instantaneous and fleeting; neutralization, while also temporary, is relatively longer-lasting. Neutralization, the doctrine says, results when suppressive effects are so severe and long-lasting that a target is put out of action for a period of time after the suppressive fire is halted. Neutralization combines the psychological effects of suppressive gunfire with a certain amount of damage. The general concept of neutralization, as distinct from the more fleeting suppression, is a reasonable one. (p. 252)

Despite widespread acknowledgement of the existence of suppression and neutralization, the lack of interest in analyzing its effects was a source of professional frustration for Dupuy. As he commented in 1989,

The British did some interesting but inconclusive work on suppression in their battlefield operations research in World War II. In the United States I am aware of considerable talk about suppression, but very little accomplishment, over the past 20 years. In the light of the significance of suppression, our failure to come to grips with the issue is really quite disgraceful.

This lack of interest is curious, given that suppression and neutralization remain embedded in U.S. Army combat doctrine to this day. The current Army definitions are:

Suppression – In the context of the computed effects of field artillery fires, renders a target ineffective for a short period of time producing at least 3-percent casualties or materiel damage. [Army Doctrine Reference Publication (ADRP) 1-02, Terms and Military Symbols, December 2015, p. 1-87]

Neutralization – In the context of the computed effects of field artillery fires renders a target ineffective for a short period of time, producing 10-percent casualties or materiel damage. [ADRP 1-02, p. 1-65]

A particular source for Dupuy’s irritation was the fact that these definitions were likely empirically wrong. As he argued in Understanding War,

This is almost certainly the wrong way to approach quantification of neutralization. Not only is there no historical evidence that 10% casualties are enough to achieve this effect, there is no evidence that any level of losses is required to achieve the psycho-physiological effects of suppression or neutralization. Furthermore, the time period in which casualties are incurred is probably more important than any arbitrary percentage of loss, and the replacement of casualties and repair of damage are probably irrelevant. (p. 252)

Thirty years after Dupuy pointed this problem out, the construct remains enshrined in U.S. doctrine, unquestioned and unsubstantiated. Dupuy himself was convinced that suppression probably had little, if anything, to do with personnel loss rates.

I believe now that suppression is related to and probably a component of disruption caused by combat processes other than surprise, such as a communications failure. Further research may reveal, however, that suppression is a very distinct form of disruption that can be measured or estimated quite independently of disruption caused by any other phenomenon. (Understanding War, p. 251)

He had developed a hypothesis for measuring the effects of suppression, but was unable to interest anyone in the U.S. government or military in sponsoring a study on it. Suppression as a combat phenomenon remains only vaguely understood.

What Is A Breakpoint?

French retreat from Russia in 1812 by Illarion Mikhailovich Pryanishnikov (1812) [Wikipedia]

After discussing with Chris the series of recent posts on the subject of breakpoints, it seemed appropriate to provide a better definition of exactly what a breakpoint is.

Dorothy Kneeland Clark was the first to define the notion of a breakpoint in her study, Casualties as a Measure of the Loss of Combat Effectiveness of an Infantry Battalion (Operations Research Office, The Johns Hopkins University: Baltimore, 1954). She found it was not quite as clear-cut as it seemed and the working definition she arrived at was based on discussions and the specific combat outcomes she found in her data set [pp 9-12].


The following definitions were developed out of many discussions. A unit is considered to have lost its combat effectiveness when it is unable to carry out its mission. The onset of this inability constitutes a breakpoint. A unit’s mission is the objective assigned in the current operations order or any other instructional directive, written or verbal. The objective may be, for example, to attack in order to take certain positions, or to defend certain positions. 

How does one determine when a unit is unable to carry out its mission? The obvious indication is a change in operational directive: the unit is ordered to stop short of its original goal, to hold instead of attack, to withdraw instead of hold. But one or more extraneous elements may cause the issue of such orders: 

(1) Some other unit taking part in the operation may have lost its combat effectiveness, and its predicament may force changes, in the tactical plan. For example the inability of one infantry battalion to take a hill may require that the two adjoining battalions be stopped to prevent exposing their flanks by advancing beyond it. 

(2) A unit may have been assigned an objective on the basis of a G-2 estimate of enemy weakness which, as the action proceeds, proves to have been over-optimistic. The operations plan may, therefore, be revised before the unit has carried out its orders to the point of losing combat effectiveness. 

(3) The commanding officer, for reasons quite apart from the tactical attrition, may change his operations plan. For instance, General Ridgway in May 1951 was obliged to cancel his plans for a major offensive north of the 38th parallel in Korea in obedience to top level orders dictated by political considerations. 

(4) Even if the supposed combat effectiveness of the unit is the determining factor in the issuance of a revised operations order, a serious difficulty in evaluating the situation remains. The commanding officer’s decision is necessarily made on the basis of information available to him plus his estimate of his unit’s capacities. Either or both of these bases may be faulty. The order may belatedly recognize a collapse which has in factor occurred hours earlier, or a commanding officer may withdraw a unit which could hold for a much longer time. 

It was usually not hard to discover when changes in orders resulted from conditions such as the first three listed above, but it proved extremely difficult to distinguish between revised orders based on a correct appraisal of the unit’s combat effectiveness and those issued in error. It was concluded that the formal order for a change in mission cannot be taken as a definitive indication of the breakpoint of a unit. It seemed necessary to go one step farther and search the records to learn what a given battalion did regardless of provisions in formal orders… 


In the engagements studied the following categories of breakpoint were finally selected: 

Category of Breakpoint 

No. Analyzed 

I. Attack [Symbol] rapid reorganization [Symbol] attack 


II. Attack [Symbol] defense (no longer able to attack without a few days of recuperation and reinforcement 


III. Defense [Symbol] withdrawal by order to a secondary line 


IV. Defense [Symbol] collapse 


Disorganization and panic were taken as unquestionable evidence of loss of combat effectiveness. It appeared, however, that there were distinct degrees of magnitude in these experiences. In addition to the expected breakpoints at attack [Symbol] defense and defense [Symbol] collapse, a further category, I, seemed to be indicated to include situations in which an attacking battalion was ‘pinned down” or forced to withdraw in partial disorder but was able to reorganize in 4 to 24 hours and continue attacking successfully. 

Category II includes (a) situations in which an attacking battalion was ordered into the defensive after severe fighting or temporary panic; (b) situations in which a battalion, after attacking successfully, failed to gain ground although still attempting to advance and was finally ordered into defense, the breakpoint being taken as occurring at the end of successful advance. In other words, the evident inability of the unit to fulfill its mission was used as the criterion for the breakpoint whether orders did or did not recognize its inability. Battalions after experiencing such a breakpoint might be able to recuperate in a few days to the point of renewing successful attack or might be able to continue for some time in defense. 

The sample of breakpoints coming under category IV, defense [Symbol] collapse, proved to be very small (5) and unduly weighted in that four of the examples came from the same engagement. It was, therefore, discarded as probably not representative of the universe of category IV breakpoints,* and another category (III) was added: situations in which battalions on the defense were ordered withdrawn to a quieter sector. Because only those instances were included in which the withdrawal orders appeared to have been dictated by the condition of the unit itself, it is believed that casualty levels for this category can be regarded as but slightly lower than those associated with defense [Symbol] collapse. 

In both categories II and III, “‘defense” represents an active situation in which the enemy is attacking aggressively. 

* It had been expected that breakpoints in this category would be associated with very high losses. Such did not prove to be the case. In whatever way the data were approached, most of the casualty averages were only slightly higher than those associated with category II (attack [Symbol] defense), although the spread in data was wider. It is believed that factors other than casualties, such as bad weather, difficult terrain, and heavy enemy artillery fire undoubtedly played major roles in bringing about the collapse in the four units taking part in the same engagement. Furthermore, the casualty figures for the four units themselves is in question because, as the situation deteriorated, many of the men developed severe cases of trench foot and combat exhaustion, but were not evacuated, as they would have been in a less desperate situation, and did not appear in the casualty records until they had made their way to the rear after their units had collapsed.

In 1987-1988, Trevor Dupuy and colleagues at Data Memory Systems, Inc. (DMSi), Janice Fain, Rich Anderson, Gay Hammerman, and Chuck Hawkins sought to create a broader, more generally applicable definition for breakpoints for the study, Forced Changes of Combat Posture (DMSi, Fairfax, VA, 1988) [pp. I-2-3]

The combat posture of a military force is the immediate intention of its commander and troops toward the opposing enemy force, together with the preparations and deployment to carry out that intention. The chief combat postures are attack, defend, delay, and withdraw.

A change in combat posture (or posture change) is a shift from one posture to another, as, for example, from defend to attack or defend to withdraw. A posture change can be either voluntary or forced. 

A forced posture change (FPC) is a change in combat posture by a military unit that is brought about, directly or indirectly, by enemy action. Forced posture changes are characteristically and almost always changes to a less aggressive posture. The most usual FPCs are from attack to defend and from defend to withdraw (or retrograde movement). A change from withdraw to combat ineffectiveness is also possible. 

Breakpoint is a term sometimes used as synonymous with forced posture change, and sometimes used to mean the collapse of a unit into ineffectiveness or rout. The latter meaning is probably more common in general usage, while forced posture change is the more precise term for the subject of this study. However, for brevity and convenience, and because this study has been known informally since its inception as the “Breakpoints” study, the term breakpoint is sometimes used in this report. When it is used, it is synonymous with forced posture change.

Hopefully this will help clarify the previous discussions of breakpoints on the blog.

Breakpoints in U.S. Army Doctrine

U.S. Army prisoners of war captured by German forces during the Battle of the Bulge in 1944. [Wikipedia]

One of the least studied aspects of combat is battle termination. Why do units in combat stop attacking or defending? Shifts in combat posture (attack, defend, delay, withdrawal) are usually voluntary, directed by a commander, but they can also be involuntary, as a result of direct or indirect enemy action. Why do involuntary changes in combat posture, known as breakpoints, occur?

As Chris pointed out in a previous post, the topic of breakpoints has only been addressed by two known studies since 1954. Most existing military combat models and wargames address breakpoints in at least a cursory way, usually through some calculation based on personnel casualties. Both of the breakpoints studies suggest that involuntary changes in posture are seldom related to casualties alone, however.

Current U.S. Army doctrine addresses changes in combat posture through discussions of culmination points in the attack, and transitions from attack to defense, defense to counterattack, and defense to retrograde. But these all pertain to voluntary changes, not breakpoints.

Army doctrinal literature has little to say about breakpoints, either in the context of friendly forces or potential enemy combatants. The little it does say relates to the effects of fire on enemy forces and is based on personnel and material attrition.

According to ADRP 1-02 Terms and Military Symbols, an enemy combat unit is considered suppressed after suffering 3% personnel casualties or material losses, neutralized by 10% losses, and destroyed upon sustaining 30% losses. The sources and methodology for deriving these figures is unknown, although these specific terms and numbers have been a part of Army doctrine for decades.

The joint U.S. Army and U.S. Marine Corps vision of future land combat foresees battlefields that are highly lethal and demanding on human endurance. How will such a future operational environment affect combat performance? Past experience undoubtedly offers useful insights but there seems to be little interest in seeking out such knowledge.

Trevor Dupuy criticized the U.S. military in the 1980s for its lack of understanding of the phenomenon of suppression and other effects of fire on the battlefield, and its seeming disinterest in studying it. Not much appears to have changed since then.