Tag Timeless Verities of Combat

Dupuy’s Verities: The Utility Of Defense

Battle of Franklin, 1864 by Kurz and Allison. Restoration by Adam Cuerden [Wikimedia Commons]

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

Defensive posture is necessary when successful offense is impossible.

From Understanding War (1987):

Even though offensive action is essential to ultimate combat success, a combat commander opposed by a more powerful enemy has no choice but to assume a defensive posture. Since defensive posture automatically increases the combat power of his force, the defending commander at least partially redresses the imbalance of forces. At a minimum he is able to slow down the advance of the attacking enemy, and he might even beat him. In this way, through negative combat results, the defender may ultimately hope to wear down the attacker to the extent that his initial relative weakness is transformed into relative superiority, thus offering the possibility of eventually assuming the offensive and achieving positive combat results. The Franklin and Nashville Campaign of our Civil War, and the El Alamein Campaign of World War II are examples.

Sometimes the commander of a numerically superior offensive force may reduce the strength of portions of his force in order to achieve decisive superiority for maximum impact on the enemy at some other critical point on the battlefield, with the result that those reduced-strength components are locally outnumbered. A contingent thus reduced in strength may therefore be required to assume a defensive posture, even though the overall operational posture of the marginally superior force is offensive, and the strengthened contingent of the same force is attacking with the advantage of superior combat power. A classic example was the role of Davout at Auerstadt when Napoléon was crushing the Prussians at Jena. Another is the role played by “Stonewall” Jackson’s corps at the Second Battle of Bull Run. [pp. 2-3]

This verity is both derivative of Dupuy’s belief that the defensive posture is a human reaction to the lethal environment of combat, and his concurrence with Clausewitz’s dictum that the defense is the stronger form of combat. Soldiers in combat will sometimes reach a collective conclusion that they can no longer advance in the face of lethal opposition, and will stop and seek cover and concealment to leverage the power of the defense. Exploiting the multiplying effect of the defensive is also a way for a force with weaker combat power to successfully engage a stronger one.

It also relates to the principle of war known as economy of force, as defined in the 1954 edition of the U.S. Army’s Field Manual FM 100-5, Field Service Regulations, Operations:

Minimum essential means must be employed at points other than that of decision. To devote means to unnecessary secondary efforts or to employ excessive means on required secondary efforts is to violate the principle of both mass and the objective. Limited attacks, the defensive, deception, or even retrograde action are used in noncritical areas to achieve mass in the critical area.

These concepts are well ingrained in modern U.S. Army doctrine. FM 3-0 Operations (2017) summarizes the defensive this way:

Defensive tasks are conducted to defeat an enemy attack, gain time, economize forces, and develop conditions favorable for offensive or stability tasks. Normally, the defense alone cannot achieve a decisive victory. However, it can set conditions for a counteroffensive or counterattack that enables Army forces to regain and exploit the initiative. Defensive tasks are a counter to enemy offensive actions. They defeat attacks, destroying as much of an attacking enemy as possible. They also preserve and maintain control over land, resources, and populations. The purpose of defensive tasks is to retain key terrain, guard populations, protect lines of communications, and protect critical capabilities against enemy attacks and counterattacks. Commanders can conduct defensive tasks to gain time and economize forces, so offensive tasks can be executed elsewhere. [Para 1-72]

UPDATE: Just as I posted this, out comes a contrarian view from U.S. Army CAPT Brandon Morgan via the Modern War Institute at West Point blog. He argues that the U.S. Army is not placing enough emphasis on preparing to conduct defensive operations:

In his seminal work On War, Carl von Clausewitz famously declared that, in comparison to the offense, “the defensive form of warfare is intrinsically stronger than the offensive.”

This is largely due to the defender’s ability to occupy key terrain before the attack, and is most true when there is sufficient time to prepare the defense. And yet within the doctrinal hierarchy of the four elements of decisive action (offense, defense, stability, and defense support of civil authorities), the US Army prioritizes offensive operations. Ultimately, this has led to training that focuses almost exclusively on offensive operations at the cost of deliberate planning for the defense. But in the context of a combined arms fight against a near-peer adversary, US Army forces will almost assuredly find themselves initially fighting in a defense. Our current neglect of deliberate planning for the defense puts these soldiers who will fight in that defense at grave risk.

Dupuy’s Verities: The Power Of Defense

Leonidas at Thermopylae, by Jacques-Louis David, 1814. [Wikimedia]

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

Defensive strength is greater than offensive strength.

From Understanding War (1987):

[Prussian military theorist, Carl von] Clausewitz expressed this: “Defense is the stronger form of combat.” It is possible to demonstrate by the qualitative comparison of many battles that Clausewitz is right and that posture has a multiplicative effect on the combat power of a military force that takes advantage of terrain and fortifications, whether hasty and rudimentary, or intricate and carefully prepared. There are many well-known examples of the need of an attacker for a preponderance of strength in order to carry the day against a well-placed and fortified defender. One has only to recall Thermopylae, the Alamo, Fredericksburg, Petersburg, and El Alamein to realize the advantage enjoyed by a defender with smaller forces, well placed, and well protected. [p. 2]

The advantages of fighting on the defensive and the benefits of cover and concealment in certain types of terrain have long been basic tenets in military thinking. Dupuy, however, considered defensive combat posture and defensive value of terrain not just to be additive, but combat power multipliers, or circumstantial variables of combat that when skillfully applied and exploited, the effects of which could increase the overall fighting capability of a military force.

The statement [that the defensive is the stronger form of combat] implies a comparison of relative strength. It is essentially scalar and thus ultimately quantitative. Clausewitz did not attempt to define the scale of his comparison. However, by following his conceptual approach it is possible to establish quantities for this comparison. Depending upon the extent to which the defender has had the time and capability to prepare for defensive combat, and depending also upon such considerations as the nature of the terrain which he is able to utilize for defense, my research tells me that the comparative strength of defense to offense can range from a factor with a minimum value of about 1.3 to maximum value of more than 3.0. [p. 26]

The values Dupuy established for posture and terrain based on historical combat experience were as follows:

For example, Dupuy calculated that mounting even a hasty defense in rolling, gentle terrain with some vegetation could increase a force’s combat power by more than 50%. This is a powerful effect, achievable without the addition of any extra combat capability.

It should be noted that these values are both descriptive, in terms of defining Dupuy’s theoretical conception of the circumstantial variables of combat, as well as factors specifically calculated for use in his combat models. Some of these factors have found their way into models and simulations produced by others and some U.S. military doctrinal publications, usually without attribution and shorn of explanatory context. (A good exploration of the relationship between the values Dupuy established for the circumstantial variables of combat and his combat models, and the pitfalls of applying them out of context can be found here.)

While the impact of terrain on combat is certainly an integral part of current U.S. Army thinking at all levels, and is constantly factored into combat planning and assessment, its doctrine does not explicitly acknowledge the classic Clausewitzian notion of a power disparity between the offense and defense. Nor are the effects of posture or terrain thought of as combat multipliers.

However, the Army does implicitly recognize the advantage of the defensive through its stubbornly persistent adherence to the so-called 3-1 rule of combat. Its version of this (which the U.S. Marine Corps also uses) is described in doctrinal publications as “historical minimum planning ratios,” which proscribe that a 3-1 advantage in numerical force ratio is necessary for an attacker to defeat a defender in a prepared or fortified position. Overcoming a defender in a hasty defense posture requires a 2.5-1 force ratio advantage. The force ratio advantages the Army considers necessary for decisive operations are even higher. While the 3-1 rule is a deeply problematic construct, the fact that is the only quantitative planning factor included in current doctrine reveals a healthy respect for the inherent power of the defensive.

Dupuy’s Verities: Offensive Action

Sheridan’s final charge at Winchester by Thune de Thulstrup (ca. 1886) [Library of Congress]

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

Offensive action is essential to positive combat results.

As he explained in Understanding War (1987):

This is like saying, “A team can’t score in football unless it has the ball.” Although subsequent verities stress the strength, value, and importance of defense, this should not obscure the essentiality of offensive action to ultimate combat success. Even in instances where a defensive strategy might conceivably assure a favorable war outcome—as was the case of the British against Napoleon, and as the Confederacy attempted in the American Civil War—selective employment of offensive tactics and operations is required if the strategic defender is to have any chance of final victory. [pp. 1-2]

The offensive has long been a staple element of the principles of war. From the 1954 edition of the U.S. Army Field Manual FM 100-5, Field Service Regulations, Operations:

71. Offensive

Only offensive action achieves decisive results. Offensive action permits the commander to exploit the initiative and impose his will on the enemy. The defensive may be forced on the commander, but it should be deliberately adopted only as a temporary expedient while awaiting an opportunity for offensive action or for the purpose of economizing forces on a front where a decision is not sought. Even on the defensive the commander seeks every opportunity to seize the initiative and achieve decisive results by offensive action. [Original emphasis]

Interestingly enough, the offensive no longer retains its primary place in current Army doctrinal thought. The Army consigned its list of the principles of war to an appendix in the 2008 edition of FM 3-0 Operations and omitted them entirely from the 2017 revision. As the current edition of FM 3-0 Operations lays it out, the offensive is now placed on the same par as the defensive and stability operations:

Unified land operations are simultaneous offensive, defensive, and stability or defense support of civil authorities’ tasks to seize, retain, and exploit the initiative to shape the operational environment, prevent conflict, consolidate gains, and win our Nation’s wars as part of unified action (ADRP 3-0)…

At the heart of the Army’s operational concept is decisive action. Decisive action is the continuous, simultaneous combinations of offensive, defensive, and stability or defense support of civil authorities tasks (ADRP 3-0). During large-scale combat operations, commanders describe the combinations of offensive, defensive, and stability tasks in the concept of operations. As a single, unifying idea, decisive action provides direction for an entire operation. [p. I-16; original emphasis]

It is perhaps too easy to read too much into this change in emphasis. On the very next page, FM 3-0 describes offensive “tasks” thusly:

Offensive tasks are conducted to defeat and destroy enemy forces and seize terrain, resources, and population centers. Offensive tasks impose the commander’s will on the enemy. The offense is the most direct and sure means of seizing and exploiting the initiative to gain physical and cognitive advantages over an enemy. In the offense, the decisive operation is a sudden, shattering action that capitalizes on speed, surprise, and shock effect to achieve the operation’s purpose. If that operation does not destroy or defeat the enemy, operations continue until enemy forces disintegrate or retreat so they no longer pose a threat. Executing offensive tasks compels an enemy to react, creating or revealing additional weaknesses that an attacking force can exploit. [p. I-17]

The change in emphasis likely reflects recent U.S. military experience where decisive action has not yielded much in the way of decisive outcomes, as is mentioned in FM 3-0’s introduction. Joint force offensives in 2001 and 2003 “achieved rapid initial military success but no enduring political outcome, resulting in protracted counterinsurgency campaigns.” The Army now anticipates a future operating environment where joint forces can expect to “work together and with unified action partners to successfully prosecute operations short of conflict, prevail in large-scale combat operations, and consolidate gains to win enduring strategic outcomes” that are not necessarily predicated on offensive action alone. We may have to wait for the next edition of FM 3-0 to see if the Army has drawn valid conclusions from the recent past or not.

TDI Friday Read: Principles Of War & Verities Of Combat

[izquotes.com]

Trevor Dupuy distilled his research and analysis on combat into a series of verities, or what he believed were empirically-derived principles. He intended for his verities to complement the classic principles of war, a slightly variable list of maxims of unknown derivation and provenance, which describe the essence of warfare largely from the perspective of Western societies. These are summarized below.

What Is The Best List Of The Principles Of War?

The Timeless Verities of Combat

Trevor N. Dupuy’s Combat Attrition Verities

Trevor Dupuy’s Combat Advance Rate Verities

The Timeless Verities of Combat

Understanding WarJames Jay Carafano, historian and Vice President for Foreign and Defense Policy at the Heritage Foundation, recently issued a call for the U.S. defense community to back off debates over “the latest doctrinal flavor of the month” and return to a focus on the classic principles of war. “Most modern military doctrine should be scrapped,” Carafano wrote. “The Pentagon would be far better served if our military thinkers got back to the basics and taught the principles of war—and little more.”

The principles of war are a list of basic concepts of warfare distilled from the writings of mostly Western military leaders and theorists that had become commonly accepted by the late 18th century, more or less. They vary in number depending on who’s list is consulted, but U.S. Army doctrine currently recognizes nine: Objective, Offensive, Mass, Economy of Force, Maneuver, Unity of Command, Security, Surprise, and Simplicity.

In 1987, Trevor N. Dupuy published what he termed “the timeless verities of combat.” These were a list of thirteen “unchanging operational features or concepts” based upon his previous twenty-five years of empirical research into a fundamental aspect of warfare, the nature of combat. He did not intend for these verities to substitute for the principles of war, but did believe that they were related to them. Dupuy asserted that the verities “describe certain fundamental and important aspects of warfare, which, despite constant changes in the implements of war, are almost unchanging because of war’s human component.”[1]

Trevor N. Dupuy’s Timeless Verities of Combat

  1. Offensive action is essential to positive combat results.
  2. Defensive strength is greater than offensive strength.
  3. Defensive posture is necessary when successful offense is impossible.
  4. Flank and rear attack is more likely to succeed than frontal attack.
  5. Initiative permits application of preponderant combat power.
  6. Defender’s chances of success are directly proportional to fortification strength.
  7. An attacker willing to pay the price can always penetrate the strongest defenses.
  8. Successful defense requires depth and reserves.
  9. Superior Combat Power Always Wins.
  10. Surprise substantially enhances combat power.
  11. Firepower kills, disrupts, suppresses, and causes dispersion.
  12. Combat activities are always slower, less productive, and less efficient than anticipated.
  13. Combat is too complex to be described in a single, simple aphorism.

Each of these concepts will be explored further in future posts.

NOTES

[1] Trevor N. Dupuy, Understanding War: History and Theory of Combat (New York : Paragon House, 1987), pp. 1-8.