The Theory of Strategy

B. H. LIDDELL HART



Liddel Hart
B. H. LIDDELL HART
Source:WikiCommons
Before going forward let's be clear on what strategy is. As per Clausewitz, in his significant work ON WAR  defined it as the " the employment of the battle as the means towards the attainment of the object of the War.". In other words strategy forms, the general outline or the plan of the war point out the course of action for different campaigns which compose the war and modulate each battle.

One defect of this definition is that it intrudes on the sphere of policy, or the higher conduct of the war, which must necessarily be the responsibility of the government and not of the military leaders it employs as its agents in the executive control of operations. Another defect is that it narrows the meaning of ‘strategy’ to the pure utilization of battle, thus conveying the idea that battle is the only means to the strategical end. It was an easy step for Clausewitz's less profound disciples to confuse the means with the end and to reach the conclusion that in war every other consideration should be subordinated to the aim of fighting a decisive battle.


Relation to Policy

To break down the distinction between strategy and policy would not matter much if the two functions were normally combined in the same person, as with a Frederick or a Napoleon. But as such autocratic soldier‐rulers have been rare in modern times and became temporarily extinct in the nineteenth century, the effect was insidiously harmful. For it encouraged soldiers to make the preposterous claim that policy should be subservient to their conduct of operations, and, especially in democratic countries, it drew the statesman on to overstep the definite border of his sphere and interfere with his military employees in the actual use of their tools.

Moltke reached a clearer, and wiser, definition in terming strategy 'the practical adaptation of the means placed at a general's disposal to the attainment of the object in view'.

This definition fixes the responsibility of a military commander to the government by which he is employed. His response is that of applying most profitably to the interest of the higher war policy the force allotted to him within the theatre of operations assigned to him. If he considers that the force allotted is inadequate for the task indicated he is justified in pointing this out, and if his opinion is overruled he can refuse or resign the command, but he exceeds his rightful sphere if he attempts to dictate to the government what measure of force should be placed at his disposal.

On the other hand, the government, which formulates war policy, and has to adapt it to conditions which often change as a war progresses, can rightly intervene in the strategy of a campaign not merely by replacing a commander in whom it has lost confidence, but by modifying his object according to the needs of its war policy. While it should not interfere with him in the handling of his tools, it should indicate clearly the nature of his task. This strategy has not necessarily the simple object of seeking to overthrow the enemy's military power. When a government appreciates that the enemy has the military superiority, either in general or in a particular theatre, it may wisely enjoin a strategy of limited aim.

It may desire to wait until the balance of force can be changed by the intervention of allies or by the transfer of forces from another theatre. It may desire to wait or even to limit its military effort permanently, while economic or naval action decides the issue. It may calculate that the overthrow of the enemy's military power is a task definitely beyond its capacity, or not worth the effort‐‐and that the object of its war policy can be assured by seizing territory which it can either retain or use as bargaining counters when peace is negotiated.

Such a policy has more support from history than military opinion hitherto has recognized, and is less inherently a policy of weakness that some apologists imply. It is, indeed, bound up with the history of the British Empire, and repeatedly proved a lifebuoy to Britain's allies as well as of permanent benefit to herself. However unconsciously followed, there is ground for inquiry whether this 'conservative' military policy does not deserve to be accorded a place in the theory of the conduct of war.

The more usual reason for adopting a strategy of limited aim is that of awaiting a change in the balance of force‐‐a change often sought and achieved by draining the enemy's force, weakening him by pricks instead of risking blows. The essential condition of such a strategy is that the drain on him should be disproportionately greater than on oneself. The object may be sought by raiding his supplies; by local attacks which annihilate or inflict disproportionate loss on parts of his force; by luring him into unprofitable attacks; by causing an excessively wide distribution of his force; and, not least, by exhausting his moral and physical energy.

This closer definition sheds light on the question, previously raised, of a general's independence in carrying out his own strategy inside his theatre of operations. For if the government has decided upon a limited aim or 'Fabian' grand strategy the general who, even within his strategic sphere, seeks to overthrow the enemy’s military power may do more harm than good to the government's war policy. Usually, a war policy of limited aim imposes a strategy of limited aim, and a decisive aim should only be adopted with the approval of the government which alone can decide whether it is 'worth the
candle'.

We can now arrive at a shorter definition of strategy as‐ the art of distributing and applying military means to fulfill (sic) the ends of policy'. For strategy is concerned not merely with the movement of forces‐‐as its role is often defined‐‐but with the effect. When the application of the military instrument merges into actual fighting, the dispositions for and control of such direct action are termed 'tactics'. The two categories, although convenient for discussion, can never be truly divided into separate compartments because each not only influences but merges into the other.

Higher, or Grand Strategy

As tactics is an application of strategy on a lower plane, so the strategy is an application on a lower plane of 'grand strategy'. While practically synonymous with the policy which guides the conduct of war, as distinct from the more fundamental policy which should govern its object, the term 'grand strategy' serves to bring out the sense of 'policy in execution'. For the role of grand strategy‐‐higher strategy‐‐is to coordinate and direct all the resources of a nation, or band of nations, towards the attainment of the political object of the war‐‐the goal defined by fundamental policy. Grand strategy should both calculate and develop the economic resources and manpower of nations in order to sustain the fighting services. Also, the moral resources‐‐for to foster the people's willing spirit is often as important as to possess the more concrete forms of power. Grand strategy, too, should regulate the distribution of power between the several services, and between the services and industry. Moreover, fighting power is but one of the instruments of grand strategy‐‐which should take account of and apply the power of financial pressure, of diplomatic pressure, of commercial pressure, and, not least of ethical pressure, to weaken the opponent's will. A good cause is a sword as well as armor. Likewise, chivalry in war can be a most effective weapon in weakening the opponent's will to resist, as well as augmenting moral strength.

Furthermore, while the horizon of strategy is bounded by the war, the grand strategy looks beyond the war to the subsequent peace. It should not only combine the various instruments but so regulate their use as to avoid damage to the future state of peace for its security and prosperity. The sorry state of peace, for both sides, that has followed most wars can be traced to the fact that, unlike strategy, the realm of grand strategy is for the most part terra incognita‐‐still awaiting exploration, and understanding.

Pure, or Military, Strategy

Having cleared the ground, we can build up our conception of strategy on its proper plane and original basis‐‐that of 'the art of the general'. Strategy depends for success, first and most, on a sound calculation and coordination of the end and the means. The end must be proportioned to the total means, and the means used in gaining each intermediate end which contributes to the ultimate must be proportioned to the value and needs of that intermediate end whether it be to gain an objective or to fulfill (sic) a contributory purpose. An excess may be as harmful as a deficiency.

A true adjustment would establish a perfect economy of force, in the deeper sense of that oft‐distorted military term. But, because of the nature and uncertainty of war, an uncertainty increased by lack of scientific study, even the greatest military ability could not achieve a true adjustment, and success lies in the closest approximation to the truth.

This relativity is inherent because however far our knowledge of the science of war is extended, it will depend on art for its application. Art can not only bring the end nearer to the means but by giving a higher value to the means, enable the end to be extended. This complicates calculation because no man can exactly calculate the capacity of human genius and stupidity, nor the incapacity of will.

Elements and Conditions


In strategy, however, the calculation is simpler and a closer approximation to truth possible than in tactics. For in war the chief incalculable is the human will, which manifests itself in resistance, which in turn lies in the province of tactics. A strategy has not to overcome resistance, except nature. Its purpose is to diminish the possibility of resistance, and it seeks to fulfill this purpose by exploiting the elements of movement and surprise.

Movement lies in the physical sphere and depends on a calculation of the conditions of time, topography, and transport capacity. (By transport capacity is meant both the means by which and the measure in which, force can be moved and maintained.)

The surprise lies in the psychological sphere and depends on a calculation, far more difficult than in the physical sphere, of the manifold conditions, varying in each case, which is likely to affect the will of the opponent.

Although strategy may aim more at exploiting movement than at exploiting surprise, or conversely, the two elements react on each other. Movement generates surprise, and surprise gives impetus to the movement. For a movement which is accelerated or changes its direction inevitably carries with it a degree of surprise, even though it be unconcealed; while surprise smoothes the path of movement by hindering the enemy's counter‐measures and counter‐movements.

As regards the relation of strategy to tactics, while in execution the borderline is often shadowy, and it is difficult to decide exactly where a strategical movement ends and a tactical movement begins, yet in conception the two are distinct. Tactics lie in and fill the province of fighting. Strategy not only stops on the frontier but has for its purpose the reduction of fighting to the slenderest possible proportions.

Aim of Strategy

This statement may be disputed by those who conceive the destruction of the enemy's armed force as the only sound aim in war, who hold that the only goal of the strategy in battle, and who is obsessed with the Clausewitzian saying that 'blood is the price of victory'. Yet if one should concede this point and meet its advocates on their own ground, the statement would remain unshaken. For even if a decisive battle is a goal, the aim of the strategy must be to bring about this battle under the most advantageous circumstances. And the more advantageous the circumstances, the less, proportionately, will be the fighting.

The perfection of strategy would be, therefore, to produce a decision without any serious fighting. History, as we have seen, provides examples where strategy, helped by favorable conditions, has virtually produced such a result‐‐among the examples being Caesar's Ilerda campaign, Cromwell's Preston campaign, Napoleon's UIm campaign, Moltke's encirclement of MacMahon's army at Sedan in 1870, and Allenby's 1918 encirclement of the Turks in the hills of Samaria. The most striking and catastrophic of recent examples was the way that, in 1940, the Germans cut off and trapped the Allies' left wing in Belgium, following Guderian's surprise break‐through in the center at Sedan, and thereby ensured the general collapse of the Allied armies on the Continent.

While these were cases where the destruction of the enemy's armed forces was economically achieved through their disarming by surrender, such 'destruction' may not be essential for a decision, and for the fulfillment (sic) of the war‐aim. In the case of a state that is seeking, not conquest, but the maintenance of its security, the aim is fulfilled if the threat is removed‐‐if the enemy is led to abandon his purpose.

The defeat which Belisarius incurred at Sura through giving rein to his troops' desire for a 'decisive victory' ‐‐after the Persians had already given up their attempted invasion of Syria‐‐was a clear example of unnecessary effort and risk. By contrast, the way that he defeated their more dangerous later invasion and cleared them out of Syria is perhaps the most striking example on record of achieving a decision‐‐in the real sense, of fulfilling the national object‐‐by pure strategy. For in this case, the psychological action was so effective that the enemy surrendered his purpose without any physical action at all being required.

While such bloodless victories have been exceptional, their rarity enhances rather than detracts from their value‐‐as an indication of latent potentialities, in strategy and grand strategy. Despite many centuries' experience of war, we have hardly begun to explore the field of psychological warfare.

From deep study of war, Clausewitz was led to the conclusion that‐‐'All military action is permeated by intelligent forces and their effects.' Nevertheless, nations at war have always striven, or been driven by their passions, to disregard the implications of such a conclusion. Instead of applying intelligence, they have chosen to batter their heads against the nearest wall.

It rests normally with the government, responsible for the grand strategy of a war, to decide whether strategy should make its contribution by achieving a military decision or otherwise. Just as the military means is only one of the means to the end of grand strategy‐‐one of the instruments in the surgeon's case‐‐so battle is only one of the means to the end of strategy. If the conditions are suitable, it is usually the quickest in effect, but if the conditions are unfavorable it is folly to use it.

Let us assume that a strategist is empowered to seek a military decision. His responsibility is to seek it under the most advantageous circumstances in order to produce the most profitable result. Hence his true aim is not so much to seek battle as to seek a strategic situation so advantageous that if it does not of itself produce the decision, its continuation by a battle is sure to achieve this. In other words, dislocation is the aim of strategy; its sequel may be either the enemy's dissolution or his easier disruption in battle. Dissolution may involve some partial measure of fighting, but this has not the character of a battle.

Action of Strategy

How is the strategic dislocation produced? In the physical, or 'logistical', sphere it is the result of a move which 

  • upsets the enemy's dispositions and, by compelling a sudden 'change of front', dislocates the distribution and organization of his forces; 
  • separates his forces; 
  • endangers his supplies; 
  • menaces the route or routes by which he could retreat in case of need and reestablish himself in his base or homeland.
A dislocation may be produced by one of these effects, but is more often the consequence of several. Differentiation, indeed, is difficult because a move directed towards the enemy's rear tends to combine these effects. Their respective influence, however, varies and has varied throughout history according to the size of armies and the complexity of their organization. With armies which 'live on the country', drawing their supplies locally by plunder or requisition, the line of communication has negligible importance. Even in a higher stage of military development, the smaller a force the less dependent it is on the line of communication for supplies. The larger an army and the more complex its organization, the more prompt and serious in effect is a menace to its line of communication.

Where armies have not been so dependent, the strategy has been correspondingly handicapped, and the tactical issue of battle has played a greater part. Nevertheless, even thus handicapped, able strategists have frequently gained a decisive advantage previous to battle by menacing the enemy's line of retreat, the equilibrium of his dispositions, or his local supplies.

To be effective, such a menace must usually be applied at a point closer, in time and space, to the enemy's army than a menace to his communications; and thus in early warfare, it is often difficult to distinguish between the strategical and tactical maneuver (sic).

In the psychological sphere, dislocation is the result of the impression on the commander's mind of the physical effects which we have listed. The impression is strongly accentuated if his realization of his being at a disadvantage is sudden, and if he feels that he is unable to counter the enemy's move. Psychological dislocation fundamentally springs from this sense of being trapped.

This is the reason why it has most frequently followed a physical move on to th enemy's rear. An army, like a man, cannot properly defend its back from a blow without turning round to use its arms in the new direction. 'Turning' temporarily unbalances an army as it does a man, and with the former, the period of instability is inevitably much longer. In consequence, the brain is much more sensitive to any menace to its back.

In contrast, to move directly on an opponent consolidates his balance, physical and psychological, and by consolidating it increases his resisting power. For in the case of an army it rolls the enemy back towards their reserves, supplies, and reinforcements so that as the original front is driven back and worn thin, new layers are added to the back. At the most, it imposes a strain rather than producing a shock.

Thus a move round the enemy's front against his rear has the aim not only of avoiding resistance on its way but in its issue. In the most profound sense, it takes the line of least resistance. The equivalent in the psychological sphere is the line of least expectation. They are the two faces of the same coin, and to appreciate this is to widen our understanding of strategy. For if we merely take what obviously appears the line of least resistance, its obviousness will appeal to the opponent also; and this line may no longer be that of least resistance.

In studying the physical aspect we must never lose sight of the psychological, and only when both are combined is the strategy truly an indirect approach, calculated to dislocate the opponent's balance.

The mere action of marching indirectly towards the enemy and on to the rear of his dispositions does not constitute a strategic indirect approach. Strategic art is not so simple. Such an approach may start by being indirect in relation to the enemy's front, but by the very directness of its progress towards his rear may allow him to change his dispositions, so that it soon becomes a direct approach to his new front.

Because of the risk that the enemy may achieve such a change of front, it is usually necessary for the dislocating move to be preceded by a move, or moves, which can best be defined by the term 'distract' in its literal sense of 'to draw asunder'. The purpose of this 'distraction' is to deprive the enemy of his freedom of action, and it should operate in both the physical and psychological spheres. In the physical, it should cause a distension of his forces or their diversion to unprofitable ends, so that they are too widely distributed, and too committed elsewhere, to have the power of interfering with one's own decisively intended move. In the psychological sphere, the same effect is sought by playing upon the fears of, and by deceiving, the opposing command.
'Stonewall' Jackson aptly expressed this in his strategical motto‐‐'Mystify, mislead, and surprise'. For to mystify and to mislead constitutes 'distraction', while surprise is the essential cause of 'dislocation'. It is through the 'distraction' of the commander's mind that the distraction of his forces follows. The loss of his freedom of action is the sequel to the loss of his freedom of conception.

A more profound appreciation of how the psychological permeates and dominates the physical sphere has an indirect value. For it warns us of the fallacy and shallowness of attempting to analyze (sic) and theorize about strategy in terms of mathematics. To treat it quantitatively, as if the issue turned merely on a superior concentration of force at a selected place, is as faulty as to treat it geometrically: as a matter of lines and angles.

Even more remote from truth‐‐because in practice it usually leads to a dead end‐is the tendency of text‐books to treat war as mainly a matter of concentrating superior force. In his celebrated definition of economy of force Foch termed this‐‐'The art of pouring out all one's resources at a given moment on one spot; of making use there of all troops, and, to make such a thing possible, of making those troops permanently communicate with each other, instead of dividing them and attaching to each fraction some fixed and invariable function; its second part, a result having been attained, is the art of again so disposing the troops as to converge upon, and act against, a new single objective.'

It would have been more exact, and more lucid, to say that an army should always be so distributed that its parts can aid each other and combine to produce the maximum possible concentration of force at one place, while the minimum force necessary is used elsewhere to prepare the success of the concentration.

To concentrate all is an unrealizable ideal, and dangerous even as a hyperbole. Moreover, in practice, the 'minimum necessary' may form a far larger proportion of the total than the 'maximum possible'. It would even be true to say that the larger the force that is effectively used for distraction of the enemy, the greater is the chance of the concentration succeeding in its aim. For otherwise it may strike an object too solid to be shattered.

Superior weight at the intended decisive point does not suffice unless that point cannot be reinforced in time by the opponent. It rarely suffices unless that point is not merely weaker numerically but has been weakened morally. Napoleon suffered some of his worst checks because he neglected this guarantee‐‐and the need for distraction has grown with the delaying power of weapons.

Basis of Strategy


A deeper truth to which Foch and other disciples of Clausewitz did not penetrate fully is that in war every problem, and every principle, is a duality. Like a coin, it has two faces. Hence the need for a well‐calculated compromise as a means of reconciliation.

This is the inevitable consequence of the fact that war is a two‐party affair, so imposing the need that while hitting one must guard. Its corollary is that, in order to hit with effect, the enemy must be taken off his guard. Effective concentration can only be obtained when the opposing forces are dispersed; and, usually, in order to ensure this, one's own forces must be widely distributed. Thus, by an outward paradox, true concentration is the product of dispersion.

A further consequence of the two‐party condition is that to ensure reaching an objective one should have alternative objectives. Herein lies a vital contrast to the single‐minded nineteenth-century doctrine of Foch and his fellows‐‐a contrast of the practical to the theoretical. For if the enemy is certain as to your point of aim he has the best possible chance of guarding himself—and blunting your weapon. If, on the other hand, you take a line that threatens alternative objectives, you distract his mind and forces. This, moreover, is the most economic method of distraction, for it allows you to keep the largest proportion of your force available on your real line of operation‐‐thus reconciling the greatest possible concentration with the necessity of dispersion.

The absence of an alternative is contrary to the very nature of war. It sins against the light which Bourcet shed in the eighteenth century by his most penetrating dictum that 'every plan of campaign ought to have several branches and to have been so well thought out that one or other of the said branches cannot fail of success'. This was the light that his military heir, the young Napoleon Bonaparte, followed in seeking always, as he said, to 'faire son thème en deux façons'. 
Seventy years later Sherman was to relearn the lesson from experience, by reflection, and to coin his famous maxim about 'putting the enemy on the horns of a dilemma'. In any problem where an opposing force exists, and cannot be regulated, one must foresee and provide for alternative courses. Adaptability is the law which governs survival in war as in life‐‐war being but a concentrated form of the human struggle against the environment.

To be practical, any plan must take account of the enemy's power to frustrate it; the best chance of overcoming such obstruction is to have a plan that can be easily varied to fit the circumstances met; to keep such adaptability, while still keeping the initiative, the best way is to operate along a line which offers alternative objectives. For thereby you put your opponent on the horns of a dilemma, which goes far to assure the gaining of at least one objective‐‐whichever is least guarded‐‐and may enable you to gain one after the other.

In the tactical field, where the enemy's dispositions are likely to be based on the nature of the ground, it may be more difficult to find a choice of dilemma‐‐producing objectives than it is in the strategical field, where the enemy will have obvious industrial and railway centers to cover. But you can gain a similar advantage by adapting your line of effort to the degree of resistance that is met, and exploiting any weakness that is found. A plan, like a tree, must have branches‐‐if it is to bear fruit. A plan with a single aim is apt to prove a barren pole.

Cutting Communications

In the planning of any stroke at the enemy's communications, either by maneuver around his flank or by the rapid penetration of a breach in his front, the question will arise as to the most effective point of aim‐‐whether it should be directed against the immediate rear of the opposing force or further back. 

When studying this question at the time that experimental mechanized forces were first created, and their strategic use was under consideration, I sought guidance on it by an analysis of cavalry raids carried out in the past, especially in the more recent wars since railways came into use. While such cavalry raids had more limited potentialities than a deep strategic penetration of mechanized forces seemed to me to promise, this difference emphasized rather than detracted from the significance of the evidence which they provided. Making the necessary adjustment, the following deductions could be drawn:
In general, the nearer to the force that the cut is made, the more immediate the effect; the nearer to the base, the greater the effect. In either case, the effect becomes much greater and more quickly felt if made against a force that is in motion, and in course of carrying out an operation, than against a force that is stationary.
In deciding the direction of a mobile stroke, much depends on the strategic position and supply conditions of the enemy forces, i.e. the number of their lines of supply, the possibility of adopting alternative lines of supply, the number of supplies likely to be accumulated in advanced depots close behind their front. After these factors have been considered, they should be reconsidered in light of the accessibility of the various possible objectives, i.e. the distance, the natural obstacles, and the opposition likely to be met. In general, the longer the distance that has to be covered, the greater the ratio of natural obstacles, but the less the ratio of opposition.

Thus, unless the natural obstacles are very severe, or the enemy has unusual independence of supplies from the base, more success and more effect is to be expected from cutting his communications as far back as possible.

A further consideration is that while a stroke close in rear of the enemy force may have more effect on the minds of the enemy troops, a stroke far back tends to have more effect on the mind of the enemy commander.

Cavalry raids in the past had often forfeited their effect by lack of care in carrying out the demolition side of their task. As a result, the prospective value of mobile raids on communications had been unduly discounted. It should be realized, too, that the flow of supplies may be interrupted not only by demolitions on the route but by actual or threatened interception of trains and lorry convoys. This form of interruption was increased in potentiality by the development of mechanized forces—because of their flexibility and power of cross‐country maneuver.
These deductions were confirmed by the experience of the Second World War‐‐ above all by the catastrophically paralyzing effect, physically and psychologically, that was produced when Guderian's panzer forces, racing far ahead of the main German armies, severed the Allied armies' communications where these crossed the far back line of the Somme, at Amiens and Abbeville.

The Method of Advance

Until the end of the eighteenth century, a physically concentrated advance, both strategic (to the battlefield) and tactical (on the battlefield) was the rule. Then Napoleon, exploiting Bourcet's ideas and the new divisional system, introduced a distributed strategic advance‐‐the army moving in independent fractions. But the tactical advance was still, in general, a concentrated one.

Towards the end of the nineteenth century, with the development of fire weapons, the tactical advance became dispersed, i.e. in particles, to diminish the effect of fire. But the strategic advance had again become concentrated‐‐this was due partly to the influence of railways and the growth of masses, partly to the misunderstanding of the Napoleonic method.

A revival of the distributed strategic advance was required in order to revive the art and effect of strategy. Moreover, new conditions‐‐air power and motor power‐‐ point to its further development into a dispersed strategic advance. The danger of air attack, the aim of mystification, and the need of drawing full value from mechanized mobility, suggest that advancing forces should not only be distributed as widely as is compatible with combined action but be dispersed as much as is compatible with cohesion. This becomes essential in face of atomic weapons. The development of radio is a timely aid towards reconciling dispersion with control.

Instead of the simple idea of a concentrated stroke by a concentrated force, we should choose according to circumstance between these variants:

  1. Dispersed advance with a concentrated single aim, i.e. against one objective.
  2. Dispersed advance with a concentrated serial aim, i.e. against successive objectives. (These will each demand preliminary moves to distract the enemy's attention and forces unless the possibility of taking alternative objectives enables us to rely on such distracting effect being produced already by the enemy's perplexity.)
  3. Dispersed advance with a distributed aim, i.e. against a number of objectives simultaneously.(Under the new conditions of warfare, the cumulative effect of partial success, or even mere threat, at a number of points may be greater than the effect of complete success at one point.)
The effectiveness of armies depends on the development of such new methods which aim at permeating and dominating areas rather than capturing lines; at the practicable object of paralyzing (sic) the enemy's action rather than the theoretical object of crushing his forces. The fluidity of force may succeed where the concentration of force merely entails a perilous rigidity.