4. DISTRIBUTION IN DEPTH AND FRONTAGE OF COMBAT FORMATIONS.[228]

The infantry combat is decided by the combined action of long firing lines. Retained forces, not launched against the enemy for the purpose of crushing him, exert no influence whatever on the decision, since they only increase losses without contributing to the fire effect. In the battles of the past, distribution in depth at the decisive stage of the combat (unless necessary as a measure of precaution, in securing the flanks, for example), was only permissible so long as the short range of the weapons allowed reserves to be kept in readiness so close to the firing line that they could assault en masse at once and without any diminution of their strength. The deciding factor, which rested in retained reserves during the Napoleonic era, lies at present in the firing line.[229]

Distribution in depth is, therefore, only a means to an end; an expedient made use of to maintain a dense firing line permanently at a constant strength; to give the firing line the impetus for the assault; to protect it against a reverse; and to secure its flanks. Victory is assured only by the simultaneous employment of superior fighting forces. A force should go into action in a deep combat formation, but it must extend its front during the fight. To launch an insufficient number of troops for combat and to reinforce them gradually is a fatal error, as we are thereby compelled to fight a superior force continually with an inferior one, without being able to take advantage of the superiority which we may actually possess.

Distribution in depth is necessary during the preparatory stage of the fight, as it enables the commander to meet unexpected developments in the situation. Moreover, it is justifiable so long as the information in regard to the strength and intentions of the enemy is insufficient. When reconnaissance work is not thoroughly performed, the force may be obliged to deploy in a direction other than the one originally chosen. This will be difficult to do as changes of front and movements by the flank can only be made when the front is narrow. Moreover, after a force is once deployed within the zone of hostile fire, it is committed to the direction chosen and can only move straight to the front. Considerable changes of front can only be executed by the lines in rear. The troops held in rear are to reinforce the firing line and to increase its density to the maximum at the decisive moment. As the losses are smaller in defense than in attack, a force can cover a broader front and keep its supports in closer proximity to the firing line in the former than in the latter case, especially if it was able to strengthen its position. The reserve, however, should be kept at a greater distance from the firing line than in attack, in order that it may retain complete freedom of movement—in covering the retreat, or in making a counter-attack—and may not be involved in the fire fight.

The reserves of the attacker are to protect the flanks, give the impetus for the assault, serve as a force upon which the attacking line can rally, and cover the re-forming of the troops after a successful attack. The several echelons of the attack formation, except the small fractions immediately supporting the firing line[233] and covering its flanks, should have become merged with that line by the time the decisive moment of the combat arrives. The commander who takes up an unnecessarily deep attack formation dispenses with an advantage; on the other hand, the one who prematurely deploys in force, exposes himself to grave danger. The troops should be sent into action in a deep combat formation, since the firing line is to be fed from the rear until the decisive moment arrives, but every available man should be thrown in for the assault.

Distribution in depth and frontage are interdependent; the greater the frontage, the less the distribution in depth, and vice versa. In every deployment for action the following question awaits solution by the troop leader: “How deep ought the formation to be and how great an extension of front is allowable.” The result of the combat depends in many cases upon a happy answer to this question. Broad combat formations have great initial energy, facilitate turning and flank movements, but their energy is not constant when the means are not available to replace casualties. In addition, the difficulty of leading, the danger of the line being penetrated, and the weakness of the flanks grow apace with the extension of front. Distribution in depth makes it possible to initiate the combat with a part of the force and to get information of the situation; to fight the action with another part of the force in accordance with this information; and, finally, to bring about the decision and reap the fruits of that decision with the third part. A deep combat formation enables the leader to exercise a constant influence on the course of action; it gives him the means with which to execute turning movements or to repulse them—something which would be entirely impossible, or, at any rate, only possible under great difficulties, with troops deployed in the first line. As only a limited number of rifles can be brought into play in a deep combat formation, it is obvious that this is an element of weakness of which an opponent deployed on a broader front, may take advantage.

Although the danger of going too far in distributing a force in depth is not inconsiderable, this is, at any rate, a smaller error than the opposite extreme, that of deploying troops, from the very start, on too broad a front.

In deciding how many men are required to occupy or attack a position, the principal point to be considered is the effect of fire. The modern long range magazine rifle will, no doubt, enable us to defend a position with a smaller force than was possible in the past with the older less improved weapons. However, combats last longer nowadays, and the shock action of Frederick the Great’s tactics is no longer practicable. The fight is carried on at longer ranges, and the tremendously costly decisive moments of the past are of rarer occurrence. As a consequence, the casualties of the whole force engaged are smaller, although, owing to unfavorable conditions, certain organizations may suffer losses quite as great as those incurred in the battles of Frederick the Great and Napoleon.[239] Instead of the sanguinary hand-to-hand fight with cold steel, we now have a prolonged fire fight carried on by a firing line which requires to be constantly fed by troops held in rear, who have to be sheltered as much as possible from hostile fire until the moment of their employment. This fire fight is frequently decided by psychological factors and without the troops suffering material losses.

“The duration of the combat under modern conditions,” writes General Négrier,[240] “leads to a considerable mental exhaustion of the troops which is apparent in nervous lassitude. This explains the impotency of leader and troops the day after a defeat and even after a victory. This lassitude is still greater on the day of the battle. While it is true that this has always been the case, the nervous exhaustion has grown in an inconceivable manner, its intensity increasing at the same rate as the invisibility of the opponent. The invisibility of the enemy directly affects the morale of the soldier, the sources of his energy and courage. The soldier who cannot see his enemy is inclined to see him everywhere. It is but a step from this impression to hesitancy and then to fear. The inertia of the troops for whole days at Magersfontain, Colenso, and Paardeberg, frequently more than 800 m. from the enemy, was not caused by their losses, but by the moral depression produced within the effective zone of rifle fire. Another factor, which governs the modern combat at short ranges, the impossibility of the commander making his influence felt in lines which are seriously engaged, is of still greater importance. The influence of the officers who lead these lines is also limited. They are scarcely able to direct the three or four men nearest them. The combat depends upon the individual fighters, and there never has been a time when the personal efficiency of the individual soldier has had a greater significance.” We should not forget that this change occurred during a period in which we no longer fight our battles with professional soldiers of long service, but, on the contrary, with peace cadres of our conscript armies raised to war strength by Reservists.

Another factor to be considered is the fighting quality of the opponent. In an action against an enemy who is a match for us, the necessity for distribution in depth is, of course, greater than when fighting against poor troops.

Considerations of importance in deciding upon the extent of front to be covered by a force, similar conditions on both sides being presumed, are—

1. Whether it is compelled to fight an independent action alone;

2. Whether it is fighting, from the preparatory to the decisive stage of the combat, as part of a larger body, with at least one, or perhaps both flanks secured;

3. Whether it has been selected to make the decisive attack against an enemy already shaken by other troops.

In the last mentioned case a sudden effect, a short, powerful blow, is required, and the maximum frontage of all the units employed on the same line is admissible. But even a force advancing to the final assault can by no means dispense with distribution in depth; supports and reserves are needed to carry forward the firing line when it has been checked, to cover its flanks, and to carry on the pursuit (second line).

The frontage of an organization whose flanks are secure and which is acting as a part of a larger force, depends upon other troops; considerable extension of front is admissible provided the firing line is constantly maintained at a strength which will enable it to gain a superiority of fire over the enemy. “While an organization which has only one flank protected, is less restricted as regards frontage, it will have to provide for distribution in depth on the exposed flank. In this case, it is a good plan to move the units held in rear toward the particular flank (echeloning). Interval and distance increase with the size of this echelon.” (Par. 290 German I. D. R.). The German Infantry Drill Regulations (par. 397) further emphasize the fact that, when well-trained infantry employs its rifles to good advantage in defense, it is very strong in front; that it can hold a position with a comparatively small force; and that, in this case, it has only one weak spot, the flank, which it must seek to protect by distribution in depth. This view is fully borne out by the recent events in South Africa and in Manchuria. Under favorable conditions (deliberate defense), a battalion fighting as part of a larger force may put all of its companies into the first line, a front of 200 m. being assigned to each. The battalion can thus defend a front of 800 m. The only restriction is the requirement that the battalion commander must be able, at all times, to direct the course of the combat.

An organization acting alone which has to fight an action independently from beginning to end under varying conditions, cannot employ all of its available strength in the first line at one time. A distribution into three parts, viz., firing line, supports, and reserve, is therefore required. During the preparatory stage, the firing line should be as weak as possible, while, for sustaining and deciding the action, the reserve should be as strong as possible. As a rule, this distribution will not come into existence until the combat has begun; it must disappear again, during the subsequent course of the fight, through reinforcement of the troops that initiated the action, thus resulting in an increase of the combat front.

While the frontage is thus increased, an equal density along the entire attacking line is not produced. This is due to the fact that one will endeavor to increase the distribution in depth only at the point where the decision is sought (offensive wings), while one will seek to obtain results by a generous expenditure of ammunition at points where the enemy is only to be contained. When a broad front has to be held with a weak force, it is a good plan to post the troops in groups. Of the attack as well as of the defense it may be said, that the skillful combination of the offensive and defensive advantages of a piece of ground is a sign of good leadership. (Austerlitz). Frequently, however, after an action is over, the assault that penetrated a line is called the main attack, and the one that failed, a demonstration. An organization fighting alone will generally begin an action by deploying on a narrow front; it will protect its flanks by distribution in depth; and, finally, mass troops at the decisive point in readiness to make the assault. The force making an assault in attack or a counter-attack in defense cannot be strong enough.

Another factor that must be considered in deciding upon the frontage is the task which a force is to perform, i.e., whether it is to make an attack or to stand on the defensive; whether it is to fight a delaying action or is to withdraw. The object of distribution in depth is to keep the firing line constantly at the same strength; this requires stronger reinforcements in attack (owing to the greater losses), than in defense, and leads, consequently, to a contraction of the front.

The number of troops which will be required to hold a given piece of ground must be determined separately in each case. The strength of the fighting line depends upon the effect of the hostile fire. Military history tells us how many troops the leader sent into action in order to gain the victory, but it seldom gives us a clue as to the number of troops that might have sufficed in the particular case.

In deploying from route column in a rencontre, the leading battalion may be fully engaged by the time the next one arrives on the battlefield. In such cases, the tactical situation may require the employment of longer firing lines than would be deemed proper for the size of the command when making a more serious attack. (Par. 357 German I. D. R.). The assailant should then endeavor to throw the enemy, who is likewise advancing, on the defensive. The situation is similar to that in which an advance guard has to cover the main body’s debouchment from a defile.

Distribution in depth, for the purpose of warding off an enveloping movement and for making a counter-attack, is more necessary in defense than in attack; besides, a greater front may be covered in the former case on account of the smaller losses. The following factors in part determine the extent of front to be occupied and the number of troops required to defend it: (1) the strength, natural or artificial, of the position; (2) obstacles in its front; (3) salient angles which can be easily enveloped; (4) the intentions of the commander (i.e., whether he contemplates fighting a purely defensive combat or one including offensive action).

Delaying actions are usually fought at long and medium ranges as purely passive defensive combats and no provision is made for replacing casualties, the object of the fight being to avoid a decision. Few men should, therefore, be placed in the firing line, but these should be supplied with abundant ammunition. However, as the force desires to avoid a decisive engagement by withdrawing, distribution in depth should be provided to protect the flanks and to facilitate breaking off the action. (Par. 419 German I. D. R.). This requires that distances be great.

Night attacks, on account of the element of surprise involved, do not require great distribution in depth; as a rule, the fight is decided in a very short time by the collision of the opposing forces. However, measures must be taken to protect the flanks, to ensure victory, and to give the first line the impetus necessary to carry it forward in case it is checked.

An attempt will now be made to give some approximate figures for the extent of front that may be occupied in various situations.

Assuming one rifle for every three meters of front occupied, the following might suffice for temporarily defending a line 1000 m. long:

Thus 0.8 men per meter would be sufficient. This is borne out by the Boer War. With a good field of fire, even a thin firing line, provided with plenty of ammunition, is capable of bringing any attack to a standstill, at least for the time being.

A defense seeking a decision requires fighting at short ranges; the firing line must be kept constantly at the same strength; losses of about one-fifth (killed, wounded, and missing) must be reckoned with; and, finally, a reserve, consisting of about a third of the effective strength of the force, is required for making the counter-attack. The firing line is, from the outset, made as dense as possible, and echelons posted on the flanks must oppose any advance against the flanks.

The following would thus suffice for defending a front of 1000 m.:

Hence, 2.4 rifles per meter of front would be available for defense.

The defense is decided by a successful counter-attack made by the reserve, whereas the attack requires an additional force to cover and assure the assembling and re-forming of the troops. The greater force is naturally required by the attacker, who must be stronger than the defender at the moment when the assault is made. The following would be required for making an attack on a front of 1000 m.:

This would be equivalent to 4.2 rifles per meter of front.

These figures can only serve as a very general guide, of course, and should be considered minima.

From a consideration of the foregoing, it appears that the maximum frontage is justifiable, when a force whose flanks are secure, occupies a position prepared for defense, or acts as a reserve and is to bring about a decision which has been prepared by other troops. On the other hand, the maximum distribution in depth is necessary for a force acting alone in attack with both flanks exposed. Between these two extremes lie many intermediate degrees, and it is therefore impossible to lay down hard and fast rules for the frontage of an attacking force. The German Infantry Drill Regulations (par. 373) accordingly fix the frontage of a company in attack at 150 m. and that of a brigade of six battalions at 1500 m. It is impossible to give a definite ratio of effective strength to combat frontage. Thus, while in attack a company puts into the line about 1.3 rifles per meter of its front, the brigade employs 4 rifles per meter, and the larger units a proportionally greater number. The necessity for distribution in depth increases with the size of the force and with the number of units composing it.

In a company, for example, a platoon is sufficient to fulfill, within certain limits, all the functions of a reserve, while in a larger force the duties of a reserve are so complex that each task (protecting the flanks, reinforcing the firing line, giving the impetus for the assault, and covering the assembling and re-forming of the attacking force) must be assigned to a separate unit. Moreover, the duration of a combat, and, in conjunction therewith, the necessity of reinforcing the firing line and covering the flanks, increases with the size of the force. During protracted periods of peace, one is too much inclined to underestimate the wastefulness of a battle and the necessity for reinforcing the fighting line; one cannot understand why 5 to 6 men will not suffice, during the course of a combat, for a front wherein only one man can use his rifle. From the foregoing it follows that the frontage does not increase in proportion to the number of men. Thus, an army corps would not occupy a front four times that of a brigade, or twice that of a division. This is best illustrated by doubling or trebling a plane area when both length and breadth have to be equally increased.[242]

The maximum frontage to be covered in attack by the firing line of a company is fixed at 150 m., in order that the density and fire power of that line may be constantly maintained during a prolonged and costly action. During shorter (i.e., rear guard actions), or less costly actions (defense), it is, however, permissible to exceed this limit. The regulations by no means insist upon a literal interpretation of this paragraph, since they mention the deployment of the entire company, when it would certainly occupy a front of about 200 m. There is no disguising the fact, however, that, when extended on a front of 200 m., it is out of the question for the company commander to lead his men.

The regulations do not fix the combat frontage of a battalion, as it depends upon the tactical situation, and the battalion commander is at liberty to place one, two, three, or four companies into the first line. The frontage of a battalion would thus be 300 meters when making an independent attack, and not exceeding 600 meters when fighting a purely defensive action as part of a larger force, in other words, a mean frontage of 400 meters.

This is also true of the regiment. The combat frontage of a regiment acting alone, will, at the start, seldom exceed that of two battalions deployed abreast. From this we obtain a frontage of 600-800 m. for the regiment when it is acting independently, and a frontage of about 1200 m. when it is fighting a purely defensive action as part of a larger force.

Military history tells us that an army corps consisting of 25 battalions, acting as a part of a larger force in a deliberately planned attack, occupies an average front of 2.5 to 5 km. According to this, the frontage of a brigade would amount to about 800-1000 m., i.e., to 6-7.5 rifles per meter of front.

The frontage of a company is definitely fixed, so as to make it easier for battalion and regimental commanders to designate combat sections; the higher leaders reckon with regimental and brigade fronts. In war, however, the numerical strength varies constantly, and it is therefore advisable not to reckon with companies, but with a corresponding number of rifles (200 on an average). The combat frontages mentioned in drill regulations only give an approximate idea of the extent of front to be covered by organizations which act as part of a larger force in an attack seeking a decision. The extent of front to be covered in other situations, under favorable or unfavorable attack conditions, requires in each case a separate estimate.

In the Boer war, we notice for the first time overextensions of front, which were undoubtedly caused by a desire to avoid the costly frontal attack.

At Magersfontain, on December 11th, 1899, the British division under Lord Methuen (7300 men) covered a front of 12 km.; and during the attack on Pieters Hill, on February 27th, 1900, the troops under General Buller (30,000 men) extended over a front of 11 km.

At Poplar Grove, 7000 Boers with 7 guns fought on a front of 17 km. (0.4 men per meter), while the British deployed 25,000 rifles, 5000 troopers, and 116 guns on a front of 32 km. (0.8 men per meter). In the engagement at Diamond Hill, on June 11th, 1900, the army under Lord Roberts (40,000 men) advanced on a front of 37 km. Such liberties could be taken only in the face of a shaken enemy who had given up all thoughts of the offensive. At Paardeberg, February 18th, 1900, the 6th Division and the Brigade of Highlanders succeeded in getting close to the enemy, but there the attack failed on account of the lack of an impetus from the rear. Even in the Russo-Japanese war the frontages were greater than those to which we are accustomed. The reason for this overextension lies in the fact that a numerically inferior assailant was desirous of vanquishing the defender, and in order to accomplish this purpose, he was obliged to make an extensive use of the spade and to put all rifles into the first line.