THE CAVALRY.—The opportunities for cavalry action in an attack depend upon the character of the defensive operations. Against a highly organised defensive position there will be no openings for mounted troops until a wide penetration gives space for manoeuvre. Before the attack during an "Encounter Battle" the cavalry will have been out on reconnaissance in front of the attacking force; during the attack they may be called on to assist by dismounted fire action, and by local counter-strokes as mounted troops (against cavalry, or against infantry disorganised by the breakdown of a movement), but must not be allowed to impair their speed or freshness; after the successful assault the Pursuit is their special duty, not necessarily on the heels of the enemy, but on lines parallel to their retreat, to hamper his movements, to round up stragglers, and to threaten their communications. Generally speaking, such a position as is required will be found on a flank, or slightly in advance of a flank of the attacking force. "Cavalry make it possible for a general to adopt the most skilful of all manoeuvres, the converging attack, and properly handled, as atAppomattoxorPaardeberg, to bring about the crowning triumph of Grand Tactics, the hemming in a force so closely that it has either to attack at a disadvantage or to surrender" (Henderson). In the Mesopotamian campaign a surprise attack of General Sir S. Maude's forces on September 27-29, 1917, against the Turkish forces assembling nearRamadie, 65 miles north-west of Baghdad, was converted into the surrender of the Turkish commander and about 4,000 all arms by the enveloping tactics of the Anglo-Indian Cavalry Division. A similar manoeuvre on March 26, 1918, by the cavalry of the Mesopotamian Field Force (commanded at that time by General Sir W. R. Marshall, {65} who succeeded after General Maude's death from cholera), resulted in the surrender of over 5,000 Turks, including a divisional commander, 22 miles north-west of Hit. The prisoners were fugitives from the battle ofBaghdadieh, and the cavalry were astride their communications. "On the morning of the Armistice (November 11, 1918) two British Cavalry Divisions were on the march east of the Scheldt, and before orders to stop reached them they had already gained a line 10 miles in front of our infantry outposts. There is no doubt that, had the advance of the cavalry been allowed to continue, the enemy's disorganised retreat would have been turned into a rout" (Sir D. Haig's Dispatches). The absence of cavalry at the critical moment has often decided the issue of a campaign. After the action ofGaines's Mill(June 27, 1862) General J. E. B. Stuart was dispatched by Lee with the Confederate cavalry on a false scent to White House, south of the York River, to which base Lee believed McClellan to be retreating. But McClellan had shifted his base to Harrison's Landing, on the James River, and the Confederate cavalry did not regain touch with the Army of the Potomac until July 3, two days after the failure of Lee's attack on Malvern Hill. Had Stuart been available with his cavalry throughout that critical period McClellan's huge trains would have fallen an easy prey to the Confederate horsemen, and the roads through the forests and swamps to Malvern Hill could have been blocked. Absence of cavalry before the first day ofGettysburg(July 1, 1863) hampered the Confederate leaders, and lack of information caused them to act with unnecessary caution when boldness would have carried everything before them. General Stuart had once more been sent away on a raiding expedition. After the victorious attack of General Early's division a handful of General Buford's U.S. cavalry enabled the defeated 1st Corps of Meade's army to save their guns and to retire unmolested. A thousand {66} Confederate sabres would have brushed Buford aside, and July 1 would have been disastrous to the National cause.
During the German offensive of March-July, 1918, "even two or three well-trained cavalry divisions might have driven a wedge between the French and British Armies. Their presence could not have failed to have added greatly to the difficulties of our task" (Sir D. Haig's Dispatches). During theBattle of Cambrai(November 20, 1917) a squadron of the Fort Garry Horse crossed the Scheldt Canal, and after capturing a German battery and dispersing a large body of infantry, maintained itself by rifle fire in a sunken road until nightfall, when it withdrew to the British lines with its prisoners. During theBattle of Amiens(August 8-18, 1918) the cavalry were concentrated behind the battle front by a series of night marches, and on the first day of the battle they advanced 23 miles from their position of assembly. Throughout the battle they rendered most gallant and valuable service. During the SecondBattle of Le Cateau(October 6-12, 1918) cavalry were instrumental in harassing the enemy in his retreat and preventing him from completing the destruction of the railway, and when the infantry were held up by heavy machine-gun fire from Cattigny Wood and Clary "a dashing charge by the Fort Garry Horse gained a footing in Cattigny Wood and assisted our infantry to press forward. Further east, Dragoon Guards and Canadian Cavalry were instrumental in the capture of Hennechy, Reumont, and Troisvilles" (Sir D. Haig's Dispatches). In the early stages of the campaign inNorth Russia(August-September, 1918) a handful of cavalry on either bank of the North Dwina River could have kept the Bolshevik forces constantly on the run, and could have prevented the successive reorganisation of their demoralised forces, which the slower progress of the pursuing infantry was unable to accomplish. A few squadrons of cavalry could have dispersed the whole {67} Bolshevik force in the Archangel Province. Tanks are usefully employed in the pursuit, as artillery, the only effective enemy of the tank, is unlikely to remain in action with the rearward troops of a disorganised enemy; and a new terror has been added to the pursuit by the advent of self-propelled, man-carrying Aircraft, armed with machine guns and bombs, and possibly even with light quick-firing artillery. During the final stages of the victoriousAllied Advancein November, 1918, the retreating German Armies were continuously harassed from the air. "Throughout the day (November 5, 1918) the roads, packed with the enemy's troops and transport, afforded excellent targets to our airmen, who took full advantage of their opportunities, despite the unfavourable weather. Over 30 guns, which bombs and machine-gun fire from the air had forced the enemy to abandon, were captured by a battalion of the 25th Division in the field near Le Presau" (Sir D. Haig's Dispatches).
THE ROYAL ENGINEERS.—The position and employment of the Royal Engineers will be determined by the commander who issues orders for the Attack, and as the main function of this corps in the Attack is the removal or bridging of obstacles to the advance, and the strengthening of the position when captured, the Royal Engineers will probably remain with the troops to which the decisive attack is entrusted.
MEDICAL ARRANGEMENTS.—The position of hospitals and clearing stations will be settled in consultation with the S.M.O. Aid posts and advanced dressing stations will be established under battalion arrangements in connection with the medical officer of the units concerned.
SUPPLY.—The position of the Train, with its reserve supplies of ammunition and of food for men and horses, will depend upon facilities for communication with the attacking force and upon security against artillery fire {68} or surprise attack from the air or land. The position will probably be well in rear, and at the junction of roads leading forward to the attacking troops. Rations will be brought up to units under arrangements by the commanders of the battalion or other units concerned.
THE COMMANDER'S POSITION.—The position of the commander who issues the orders for the Attack must be fixed, and must be made known to subordinate commanders, as it will be the place to which reports will be sent. In the case of a small force the commander will generally stay with the General Reserve; if the force is fairly large, and composed of all arms, he will probably be on the main artillery position; but in the case of a large force he should be well out of reach of the distraction of local incidents. If the commander of a large force moves from his stated position he must leave a senior officer of his staff to represent him on the spot and to forward urgent communications to him in his changed position. In the case of a small force a commander who vacates his stated position must arrange to leave a runner in the position stated as his headquarters, in order that messages may reach him without delay.
BATTLE REPORTS.—The successful exploitation of success depends largely on the accuracy of the information gained by the commander from all parts of the battlefield. Reports are required from all who have information to impart and they should be made out on previously prepared message cards, stating the exact position of the sender at the time of the report; the progress made by the unit under the command of the sender, or by neighbouring or other units whose action has been observed; the degree of the enemy's resistance; enemy movements; and the plans of the officer making the report and the method to be adopted in carrying out such plans.
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REORGANISATION AND PURSUIT.—Once a successful assault has been delivered, subordinate commanders must immediately regain control of their commands, and must see that the fleeing enemy is pursued by fire, while local reserves follow up and secure the position against counter-attack. Superior commanders must take steps to organise the pursuit, to cut off the enemy's line of retreat, and to complete his overthrow. No victory is ever complete if the enemy is permitted to retire unmolested from the field of battle, and given time to recover order and moral. "Never let up in a pursuit while your troops have strength to follow" was a favourite maxim of Stonewall Jackson. The pursuit is the task of the infantry until it is taken over by aircraft, cavalry, and tanks, and the limits to which the infantry will carry the pursuit will be fixed by the commander, who will bear in mind the principle that "Success must be followed up until the enemy's power is ruined" ("Field Service Regulations," vol. ii. (1920)). If the fruits of victory are to be secured the work must be put in hand whilst the enemy is still reeling under the shock of defeat. A few hours' delay gives him time to recover his equilibrium, to organise a rearguard, and to gain several miles on his rearward march. In modern warfare motor transport may enable the comparatively immobile infantry to achieve the mobility of cavalry, if arrangements for embussing them have previously been made, and in a few hours infantry may thus be transported beyond the reach of pursuit.
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"Only by the rifle and bayonet of the infantryman can the decisive victory be won."—MARSHAL HAIG.
The formations in which Infantry move to the Attack must be such as will enable them to achieve their object by the combination of Fire and Movement. For this purpose, the forward troops must be furnished with supports belonging to the same unit as themselves, in order that a connected leading may produce a joint action of the whole.
THE PLATOON.—The smallest unit which can be divided into independent bodies, each capable of Fire and Movement, is the platoon, the four sections of which can pin the enemy to his position by fire and can manoeuvre round his flanks. The normal distribution of the platoon for the Attack is either the Square or the Diamond Formation. In theSquare Formation, two sections are forward covering the frontage allotted to the platoon, and the remaining two sections are in support, in such formation as may keep them in readiness for instant manoeuvre with due regard to the avoidance of unnecessary loss. In theDiamond Formation, one section leads to reconnoitre and to pin down the enemy, while the remaining three sections are held in readiness to manoeuvre for the decisive attack at the point in the enemy's defence which offers the best prospect of success. The Diamond Formation is that best suited to an Attack in an Encounter Battle, when the nature of the enemy's dispositions are imperfectly known. It possesses the great advantage of preserving {71} the power of manoeuvre for three-quarters of the platoon until the action of the leading section has developed the situation.
In each case (except when the Attack is launched against a highly organised defensive position), the forward sections will be preceded byGround Scouts, to find the most covered line of advance and the best fire positions, and to guard against ambush. These Ground Scouts advance until checked, when they remain in observation until joined by the leading sections. During the early stages of the Attack in an Encounter BattleFlank Scoutsmay be required until such time as the deployment of the platoon renders them unnecessary.
Against a highly organised defensive system platoons may not be able to advance to the Attack without a barrage, and it is essential that all movements should conform exactly to the timing of the barrage and that the troops should keep under the back edge of the shrapnel curtain, so as to deliver their assault before the enemy has time to bring rifles and machine guns into play. Under such circumstances, Ground scouts must be dispensed with. Such a position will not be attacked without careful previous reconnaissance and the lines of advance will have been chosen beforehand. The Square Formation will be that usually adopted for attacks on highly organised defensive positions, with the two rifle sections forward and the two Lewis-gun sections in support. The Lewis-gun sections are thus able to protect the flanks of the rifle sections, and to deal with isolated enemy machine guns, or concealed bodies of riflemen, which might come into action with reverse or enfilade fire after the forward sections have passed over the occupied ground.
THE PLATOON COMMANDER.—The platoon commander must explain the situation to his subordinates and point out the line of advance. He should usually move with the forward sections during the preparatory {72} phase of an Attack, and when the forward sections have been committed to the Attack he should assume control of the supporting sections and move with them. If his platoon is in support, he will thus be with the forward sections before the platoon is involved in the fight. The success of Infantry in the Attack depends not only on dash, control, and leading, but upon the intelligent co-operation of support commanders, who must keep themselves acquainted with the course of the battle by intelligent observation and will thus possess an "appreciation of the situation" before involving their men in action, and can direct the supports to the right spot at the right time, to influence the battle by fire and by movement, without hesitation or delay.
THE COMPANY.—The normal distribution of the company, when acting with other companies of the battalion, is two platoons forward and two in support. To meet the expectation of a stubborn resistance, or to cover an unusually extensive frontage, three platoons may be forward, with one in support; and where information as to the enemy's dispositions is lacking, but strong opposition is unlikely, one platoon may be forward with three in support, thus enabling the company commander to use any or all the supports to influence the attack on obtaining information as to the point in the enemy's position which offers the best prospect of success. When the frontage allotted to a company is above the normal, the leading platoons should not endeavour to cover the whole front, but gaps should be left between them; otherwise the men will be so widely extended as to deprive the leaders of the power of control.
When a company is acting independently, the normal formation will be two platoons forward, with one in support, and one in reserve.
THE COMPANY COMMANDER.—The company commander will allot the tasks and the frontages of his {73} platoons and give orders as to their distribution, and must state where he will be himself during the Attack. His position will be determined by the necessity of keeping informed throughout the Attack of the situation and of the progress of his platoons, and he is responsible that all essential information on these points is passed back to the battalion commander. He must also keep in touch with companies on his flanks, sending out patrols for this purpose, if necessary; and must use every opportunity afforded by the fire or smoke provided by other units or arms to get forward or round the enemy's flanks. He will use his supporting platoons to push through where the resistance is weak in order to turn the flank of those portions of the enemy which are holding up the advance. As soon as this temporary phase has been brought to a successful conclusion the company commander must reorganise his platoons and secure their advance on the objective. When the objective has been gained the position must be consolidated and patrols sent out to prevent surprise.
THE BATTALION.—The distribution of the battalion depends entirely upon the nature of the task allotted to it. Where the enemy's dispositions are known and considerable resistance is anticipated in the earlier stages of the Attack, the battalion will normally be distributed with two companies forward, one in support and one in reserve. The forward body should thus be strong enough to develop the Attack to such a point that a decisive blow can be delivered by the supports against the main resistance, and the reserve company is in hand for the completing stages of the action or for stabilising the local battle. Where the enemy's dispositions and the degree of resistance are still the subject of conjecture, one company only may be forward, with two in support, so that the main strength of the battalion will not be committed to any definiterôlebefore it is needed and before the situation of the enemy is discovered.
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THE BATTALION COMMANDER.—"The powers of personal control of a battalion commander upon the field of battle are limited, and success will depend, in a great measure, on the clearness of the orders which commit his leading companies to the Attack" ("Infantry Training, 1921"). The battalion commander should be supplied with any details concerning the enemy and of co-operating troops. He must understand his objective, the limits of his frontage, and the extent of help which he will receive from the other arms. In addition to such information as is supplied regarding the enemy's strength and dispositions, particularly with regard to wire (or other obstacles) and machine guns, he must ascertain the best positions of assembly for his companies, the best lines of approach to the objective, the most covered line of advance for his supports and reserves, and the best position for his own headquarters during each stage of the Attack. In his orders for the Attack he will reveal all information concerning the movements and dispositions of the enemy and of co-operating troops and arms; he will allot tasks to the companies and to the machine-gun platoon (if not brigaded) and will define the frontage of the forward companies; he will also detail the assembly positions, give compass-bearings for the advance, describe the action of other arms in support, make the necessary signalling arrangements, notify the zero hour, arrange for the synchronisation of watches, notify his own position before, during, and after the Attack, and indicate the point to which reports are to be sent, notify the medical arrangements, and issue instructions as to the collection of stragglers, the escort and destination of prisoners, the supply of ammunition, and the equipment to be worn. The quartermaster will receive orders as to the bringing up of rations during the battle. Before issuing to the Attack a proportion of officers and other ranks will be detailed to remain behind, to replace casualties when the engagement is over.
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The position of the battalion commander will be chosen with a view to keeping in touch with the progress of the Attack in all its stages and of influencing the fight by means of the reserves. Personal control is difficult to exercise once troops are committed to the fight, but opportunities for rapid decision were frequently offered to battalion commanders in the Great War, and seized with a success which transformed a check into a victory. In 1916 a battalion commander of the Coldstream Guards, seeing his command disorganised by fire and resistance, by personal example rallied and reorganised the waves of the Attack and added the necessary momentum to the assault, which then reached its objective. On April 14, 1917, the commander of a battalion of the Royal Newfoundland Regiment witnessed the launching of a local counter-attack by the Germans on the village ofMonchy-le-Preux, and by a rapid advance with the fighting portion of his headquarters, staved off the attack until the arrival of reinforcements from the 88th Brigade enabled it to be driven back in disorder. On November 30, 1917, during the German counter-attack from Fontaine Notre Dame to Tadpole Copse, in the Northern Sector of theCambraizone, the Germans forced their way into our foremost positions, and opened a gap between the 1/6th and 1/15th London Regiments. Local counter-attacks led by the two battalion commanders with all available men, including the personnel of their respective headquarters, once more restored the situation. In March, 1918, during the most critical period of the German thrust at Amiens, a battalion commander of the Border Regiment again and again, on horseback and on foot, personally restored the situation.
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"The soul of the Defence is the Counter-Attack."—MARSHAL FOCH.
Defensive action may be initiated by a commander in the field, or it may be imposed upon him by the enemy, and a commander may rely upon fortification to assist him in defeating the enemy, or he may employ manoeuvre to effect or to postpone a decision.
A commander may desire to pin the enemy to an attack upon a fortified position, garrisoned by a portion only of his force, while he detaches another (and probably greater) portion to attack the enemy from an unexpected quarter. An outstanding example of this form of action is exhibited in theBattle of Chancellorsville(May 2-3, 1863), where Lee kept at bay Hooker's army of 90,000 with one-third of his force and detached Stonewall Jackson with 30,000 men to attack the Federal rear. Action of this kind is peculiarly effective, but it requires a secrecy which modern aircraft would almost certainly unveil, and if the manoeuvre failed to escape observation it would probably result in disaster both to the retaining force and to the detached troops.
A different form of the combination of defence with manoeuvre is the Defensive-Offensive battle, with examples of which the history of Warfare is amply supplied—Marengo, Austerlitz, and Waterloo being typical battles of this nature. In this form of defensive action a commander invites the enemy to attack a well-chosen position, and after exhausting the enemy's strength and holding up the assault, the commander passes from the guard to the thrust and overwhelms {77} the exhausted foe by an irresistible and sustained counter-attack with all the means at his disposal.
A position is sometimes occupied as a matter of necessity, sometimes merely as a matter of tactical prudence. AtNachod(June 27, 1866) the Prussian Advanced Guard hurriedly established a defensive position and kept at bay the whole Austrian Army, while the Prussian Army emerged in security from a defile and manoeuvred into battle array. ThePass of Thermopylaewas occupied in B.C. 480 by 1,400 Greeks under Leonidas, King of Sparta, to withstand the Persian hosts of Xerxes, and although the Greek force was destroyed by an attack from the rear (through the disclosure of a secret path by a renegade in the Persian service), the resistance offered to the "invincible" Persians emboldened the Greeks in their future encounters, and led to the ultimate defeat of the invaders. According to the legendary history of Rome, Horatius Cocles and two companions defended theSublician Bridgeover the Tiber against Lars Porsena and the whole army of the Etruscans. This legendary heroism was equalled or surpassed during theSecond Battle of the Somme(March 21, 1918). "The bridges across the Crozat and Somme Canals were destroyed, though in some cases not with entire success, it being probable that certain of them were still practicable for infantry. Instances of great bravery occurred in the destruction of these bridges. In one case, when the electrical connection for firing the demolition charge had failed, the officer responsible for the destruction of the bridge personally lit the instantaneous fuse and blew up the bridge. By extraordinary good fortune he was not killed" (Sir D. Haig's Dispatches). AtRorke's Drift(January 22, 1879) a force of 80 other ranks of the 24th Regiment, under Lieutenants Chard and Bromhead, with about 40 hospital cases, drove off the repeated attacks of 4,000 Zulus, part of Cetewayo's army which had surprised and annihilated the garrison {78} atIsandhlwanaearlier the same day. An astounding feat of arms was performed by a small body of troops during the withdrawal of the British Army in face of the overwhelming German attack at theSecond Battle of the Somme. A detachment of about 100 officers and men of the 61st Brigade, 20th Division, was detailed to cover the withdrawal of their division atLe Quesnoy(March 27,1918). Under the command of their Brigade-Major (Captain E. P. Combe, M.C.) the detachment successfully held the enemy at bay from early morning until 6 p.m., when the eleven survivors withdrew under orders, having accomplished their task.
There are many instances of the occupation of an area for an actual or potential tactical purpose. Before theBattle of Salamanca(July 22, 1812) a Spanish force had been detached by Wellington to cover a ford of the River Tormes by occupying the castle of Alba de Tormes, but the force was withdrawn without Wellington's knowledge, and Marmont's defeated army retired unmolested over the ford to the fortress of Valladolid. In the campaign of 1814, Napoleon placed a garrison of 1,200 in theFortress of Soissons, but on March 3,1814, the garrison capitulated without exhausting all the means of defence as the regulations of War ordain, and the bridge at Soissons enabled Blücher and Bülow to unite their forces across the River Aisne. In the Waterloo campaign, Wellington stationed 17,000 men atHalandTubize, 8 miles from his right on the field of battle at Waterloo, to repel a possible turning movement and to form a rallying point if his centre was broken, and with 67,000 men took up a position astride the Nivelle-Brussels and Charleroi-Brussels roads which met at Mont St. Jean. He was deprived of the services of this detachment and modern criticism has been directed against this disposition of his forces. It is, however, permissible to suggest that the security of his right flank, and the possession of a rallying point, inspired him with the confidence which enabled him to {79} withstand the sustained attacks of Napoleon until the arrival of Blücher's corps permitted him to overwhelm his adversary.
A further form of defensive action is the occupation of a series of extemporised positions and the orderly withdrawal to a further series before the actual assault of the enemy, resistance being combined with manoeuvre for the purpose of delaying the enemy's advance or of holding up his pursuit. Delaying action of this kind is commonly employed in rearguard fighting, when the object to be gained is time rather than position, and the offensive action of the defender is limited to local counter-attacks at favourable or desperate moments. But the guiding principle in all defensive operations, including delaying action, must be that "when an enemy has liberty of manoeuvre, the passive occupation of a position, however strong, can rarely be justified, and always involves the risk of crushing defeat" ("Field Service Regulations," vol. ii. (1920)).
THE OFFENSIVE SPIRIT.—Although there are many forms of defensive action the soul of the Defence in every case is a vigorous offensive spirit. In the Active Defence, the Decisive Counter-Attack, ending in the overthrow of the enemy, is the manoeuvre originally in view when the defensiverôleis adopted. In the Passive Defence against superior numbers. Local Counter-Attacks end with the recapture of a tactical point or the repulse of a determined assault, and in the Delaying Action they overwhelm by surprise fire or assault a detached force which has advanced with such rapidity as to enable the defenders, without undue risk, to cut off and annihilate the isolated enemy body. Whatever the tactical situation, it is by the vigour of the offensive spirit alone that success may be achieved in the face of a determined enemy.
MODERN WARFARE.—In modern warfare the defensive position plays a part of increasing importance, owing {80} to the great power conferred on the defence by modern armaments. "Machine guns and barbed wire permit the rapid organisation of defensive points of a value which cannot be disputed. In particular, they have given to a trench, or to a natural obstacle, a solidity which permits a front to be extended in a manner unsuspected before this war; they permit the prompt consolidation of a large system that is easy to hold" (Marshal Foch). "The modern rifle and machine gun add tenfold to the relative power of the Defence as against the Attack. It has thus become a practical operation to place the heaviest artillery in position close behind the infantry fighting line, not only owing to the mobility afforded by motor traction but also because the old dread of losing the guns before they could be got away no longer exists" (Marshal French). It is thus possible to hold the forward positions of a highly organised defensive system with a minimum of exposure to loss, the extra strength of the position counterbalancing the reduction in numbers, but a preference for defensive action of this kind may generally be regarded as an admission that a victorious outcome of the campaign is not anticipated at the time of its adoption in the theatre in which it is employed. "It is of paramount importance that in those parts of a theatre of operations where a commander aims at decision a war of movement must never be allowed to lapse into position warfare so long as a further advance is possible. Position warfare can never of itself achieve victory" ("Field Service Regulations," vol. ii. (1920)). However strong entrenchments may be they will not defeat the adversary's main armies, nor can they withstand indefinitely the attacks of a determined and well-armed enemy. It is scarcely even probable that an army behind entrenchments can by that means alone inflict such losses on its assailants as will enable the initiative, or liberty of manoeuvre, to be regained and the assailant's main armies to be defeated. The operations on both sides {81} are in the nature of a siege, and however prolonged the siege, the advantage will be gained in the long run by superiority of aggressive action in the air and over and under the ground. In addition to the absence of opportunity for the grand offensive there are two further points of difference between defensive action in Position Warfare and the defence in a War of Manoeuvre. The first of these is the inevitable absence of flanks to be assailed, as the operations necessitate a connected line of strong points from sea to sea, or from the sea to the impassable barrier of neutral territory. Mounted troops are therefore doomed to inaction in their most important sphere, until the lines have been breached and the enemy is forced to retreat, and the opportunities for delivering flank attacks are meanwhile confined to the infantry, and will be due to irregularities in the alignment of the strong points, upon which enfilade fire may be brought to bear. The second point of difference is the abundance of time at the disposal of commanders for developing and rehearsing elaborate systems of attack and defence, and for obtaining detailed plans of the hostile works, through continuous reconnaissance by the Air Service. In most countries there must be, of necessity, a prolonged period of inactivity on both sides in a Position War, owing to the severity of winter conditions, or to the occurrence of the rainy season, and during that period it will seldom be possible to penetrate the enemy's main defences on such a scale as to bring about the grand offensive. But this is a period of inactivity in appearance rather than in fact, for no defensive system is ever perfect, no strong point but needs further consolidation, new trenches are constantly constructed or improved, and fresh areas are covered with wire entanglements. Guns of all calibres, underground mines and light mortars are ever at work, demolishing, wounding, and killing, while lachrymatory and asphyxiating shell-fire is to be expected at all times. On a smaller scale, snipers on both sides have a daily bag, and {82} observers are ever at their posts noting every change, however insignificant, and every new piece of work; "listening posts" are detecting hostile plans, while patrols are collecting information and raiding parties are reconnoitring, destroying defences, and inflicting losses, it being the first principle of a raid that it should result in greater losses to the enemy than to the troops which carry it out.
ENTRENCHMENTS.—Entrenchments have been employed in the defence from the earliest times. The Roman walls in Britain, the Great Wall of China, the earthworks in the Russian War of 1854-1855, in the American Civil War of 1861-1864, in the Russo-Turkish War of 1878, and the Russo-Japanese War of 1904-1905 are notable examples. But in no war previous to that of 1914-1918 have they played so important a part.
One of the most famous series of entrenchments in previous wars were those constructed in 1810 by Colonel R. Fletcher, of the Royal Engineers, atTorres Vedras. These fortifications extended for 50 miles and contained 126 closed works, mounting 247 guns, and behind these lines Wellington amassed stores and reinforcements until the retreat of Masséna enabled him to resume the initiative. In front of these lines everything that could support the French armies had been removed; behind them Wellington's forces were well provided in every respect. On October 10, 1810, Masséna was confronted by the entrenchments, the existence of which had been kept a profound secret, while their strength prevented them from being carried by assault. Before the end of October a Portuguese spy wrote to Wellington: "Heaven forgive me if I wrong the French in believing they have eaten my cat" (Napier). During the night of November 14-15, Masséna broke up his camp and withdrew. But it was not the lines of Torres Vedras which won back the Peninsula. Spain and Portugal were saved by the bold march northwards {83} to Vittoria. "In six weeks Wellington marched, with 100,000 men, 600 miles, passed six great rivers, gained one decisive battle, invested two fortresses, and drove 120,000 veteran French troops from Spain" (Napier).
DEFENSIVE SYSTEMS.—"Whether it is the intention of the commander to resume the offensive at an early date or whether it is likely that the defensive system will be occupied for a considerable period, the principles on which the construction of all defences should be undertaken are the same. All defensive systems should be planned from the outset in such a way that they can easily be adapted to the requirements of a prolonged defence. The ground must be thoroughly reconnoitred and should at the first be divided into a series of tactical posts and defended localities. These posts should be self-supporting, but should be so sited that the garrisons mutually support each other by fire. The gaps between the posts must be covered by the fire of the garrison of the posts, and machine guns may also be sited to bring fire to bear from positions in rear and to the flanks" ("Infantry Training, 1921"). This principle must govern the choice of the position to be defended as well as the organisation of the position for defence, and troops detailed for the defence of an area must continue to improve the defensive arrangements in that area until such time as the offensive is resumed.
CHOOSING A POSITION.—The framework of the modern defence consists of artillery and machine guns; into this framework are fitted the defence posts or defended localities garrisoned by infantry, who are responsible for holding their ground at all costs and for inflicting the greatest possible loss on the enemy. A commander will require a position which affords elasticity for increasing the resistance as the attackers penetrate the defences, and depth will thus be essential. He will require a position wide enough to prevent the whole of his front being masked by a retaining attack of a part of the {84} enemy's forces while a strong flank attack is simultaneously delivered; and in a War of Manoeuvre he will require facilities for the Decisive Counter-Attack.
The depth of the position will develop automatically in a War of Position, but it must always be sufficient to enable troops to assemble in rear of the forward position before moving up and to afford rest to troops when withdrawn from the front line. The width of the position will generally depend upon the strength of the defending force, the guiding principle being to keep about half the force in General Reserve; if, therefore, the remainder of the force is insufficient for the purpose of holding the defences the position is too wide for the tactical requirements of the Active Defence. In Position Warfare, however, a defensive system must necessarily be extended beyond the limits that are practicable in the Active Defence, and the numbers available for the garrison are supplemented by denying ground to the attack by means of obstacles, the removal of which is prevented by machine-gun and rifle fire.
THE OUTPOST ZONE.—For the Active Defence of a position the defensive system will consist of an Outpost Zone and a Battle Position. The Outpost Zone is garrisoned by a protective force which keeps a constant watch on the enemy and absorbs the first shock of the attack, watch being kept by means of well-concealed sentry posts on the Line of Observation, supported by a chain of small self-contained defensive posts, while resistance is offered by a series of self-contained, mutually supporting defence posts on the Outpost Line of Resistance.
THE BATTLE POSITION.—The Battle Position will be established in the area in which the commander decides to fight out the battle and break the enemy's attack. It therefore forms the keystone of the whole defensive position and must be organised in depth to afford elasticity for defensive action. "In principle, in order to protect {85} the battle position from being obliterated by a preliminary bombardment, it should be beyond effective range of the enemy's mortars" ("Field Service Regulations," vol. ii. (1920)).
THE SEMI-PERMANENT SYSTEM.—When a campaign is prolonged in any area without decisive results a War of Position may be developed by one or both of the combatants. In such cases the Outpost Zone is developed into an intricate trench system, with protective avenues leading from front to rear and with deep dugouts to protect the garrison from artillery fire. The Battle Position will probably coincide with the Outpost Zone, the trenches being used for the purposes of observation until the fire positions are manned to resist an assault.
In parts of the line on the Western Front of the Great War, "Pill-box" forts, constructed of concrete, took the place of continuous lines of trenches. These machine-gun forts were garrisoned, according to size, by groups from 5 to 50 strong, and were echeloned in plan, to sweep all approaches, and together to command with their mutually supporting fire the whole area over which they were spread, the intervening ground being entangled with wire so placed as to invite attacking troops into places where flanking fire may be poured into them. The advantages of the pill-box system over the continuous line of strong points are principally defensive. Fewer men are required for them than for the trench systems, and there is less liability of loss from artillery fire. But there are certain grave disadvantages. Well-directed artillery fire is liable to destroy some of the pill boxes, and a direct hit from a heavy gun will possibly put a larger fort out of action, thus crippling the defence by the removal of a peg on which the whole scheme depends. Supports and reserves are necessarily far in rear and must be brought up through the open to repel successful attacks, while a defensive scheme {86} composed entirely on the pill-box plan is less suitable for aggressive action than entrenchments, there being fewer facilities for assembling troops prior to the attack.
COMMON CHARACTERISTICS.—Whatever the system of defence or phase of warfare, every commander must guard his flanks and keep in touch with neighbouring units. He must always be ready to assist a neighbouring commander by enfilade fire or by a relieving counter-attack; or to throw back a defensive flank in the event of a neighbouring post being captured by the enemy. Each post, occupied for the Defence (except in Delaying Actions, where manoeuvre takes the place of a settled resistance), forms a self-contained centre of resistance, capable of all-round fire, and the duty of the garrison is to defend the area allotted to it to the last man and the last round.
THE ACTIVE DEFENCE.—The Active Defence may be considered according to the reason which prompted the commander of the force to occupy the position. It may have been deliberately chosen as a position which the enemy must attack, and in the hope of delivering during that attack a crushing and decisive counter-blow; or it may have been chosen of necessity, to meet an attack by deployment on the ground of the encounter, with the same hope of delivering a decisive counter-stroke when the opportunity arrives.
There is little difference in the steps to be taken by the commander, as in the first case a General Reserve is specially detailed for the counter-stroke; and in the second, the position will be held with as few troops as the tactical situation permits, in order to provide as large a General Reserve as possible for the Grand Offensive. A commander will be influenced by many considerations in his choice of a defensive position:—
(i)The position must suit the plan of operations; it must be "in the enemy's way," and this the commander must be able to judge from the map. It is {87} to be noted that to bar the enemy's way it is not always essential to get astride his lines of advance, as a position on parallel lines, threatening his flank and rear, cannot be ignored by the enemy, unless he is strong enough to detach a part of his force to mask the defender's position, while he proceeds to his objective with his main army. "It was a mistake to assume that in order to cover Turin one had to stand astride the road leading to that town; the armies united at Dego would have covered Turin, because they would have stood on the flank of the road leading to that town" (Napoleon).
(ii)The position must not be too extensivefor the troops at the disposal of the commander, and this will be governed by the extent of the line to be actually held. It will consist of a series of mutually supporting tactical points, which can be held as "pivots on which to hinge the defence of the position," and the object must be to obtain the maximum of fire effect on all ground over which the enemy can advance with the minimum of exposure to his fire. A rough-and-ready rule is that unless one rifle per yard of the frontage occupied can be supplied by the "troops to hold the position" (which should not exceed one-half the available force) then the position is too extensive and should be narrowed. On the other hand, too narrow a front may enable the enemy to develop, early in the engagement, strong flank attacks, which may make the position untenable before the time is ripe for the assumption of the offensive. TheCondé-Mons-Bincheline held on August 22-23, 1914, by Sir J. French's army (I. Corps, General Sir D. Haig; II. Corps, General Sir H. L. Smith-Dorrien) had a total width of 25 miles, and the troops at disposal, including General Sir E. H. H. Allenby's Cavalry Division, consisted of about 75,000 all arms. The frontage actually held did not exhaust half this force at the rate of one rifle per yard, and a position in rear had also been selected, between Jerlain and Maubeuge, with a frontage of 15 miles. TheRetreat from Monswas {88} due not to the excessive width of frontage, but to the success of the German attack on the French V. Corps at Charleroi (August 23, 1914), which left the right flank of the British Army "in the air," while two German Corps were working round the left flank. The British III. Corps (General Sir W. P. Pulteney) did not arrive until the retreat was in full swing. At theFirst Battle of Ypres(October 31, 1914) many parts of the line were held with one rifle for 17 yards, and there were no Supports or Local or General Reserves. Yet the line was not only maintained but a counter-attack at Gheluvelt thrust the attacking Germans behind their entrenchments.
(iii)There must be a clear field of fireto prevent the enemy approaching unmolested within effective range, and particularly within close range, from which the enemy will endeavour to establish an ascendency in the fire-fight.
(iv)The flanks must be secure, or at least as strong as possible. A flank resting on a deep river or a marsh may be regarded as secure, and a flank extending to the sea, or to the boundary of a neutral State. A flank on high ground which commands all approaches and provides means of distant observation may be called strong. It is a great advantage if one flank can be posted so strongly as to compel the enemy to make his main attack on the other, as this will enable the defender to forecast the direction of the decisive attack and to dispose his General Reserve to meet and overwhelm it.
(v)There should be facilities for coveron the position and concealed avenues of approach from the rear. A crest affords cover on the reverse slopes and woods provide concealment, while time enables artificial means to be adopted. Tactical cover can be provided by cavalry and advanced troops in the early stages of manoeuvre-battle, and in removing this cover the troops can withdraw in such a way as to lure the enemy on {89} to a false position. They can also induce premature deployments by the enemy, and movements across the front of the real position.
(vi)There should be good artillery positionsto provide effective fire on all hostile avenues of approach, and counter-battery work on hostile artillery positions. There should also be firm ground and good roads for the movement of guns, and an absence of landmarks for the enemy to range on. Guns of the heaviest calibre take part in all modern battles, their disposition being settled in conference with the artillery commander. A battery of field artillery requires 100 yards frontage for its six guns, and there is usually an interval of 25 yards between batteries.
(vii)There must be depthto allow for the disposal and movement of the Supports and Reserves, and for manoeuvres to recapture the forward defences, or to issue to the counter-attack.
(viii)There must be good lateral and frontal communicationin order that any part of the line can be quickly reinforced. A position astride an unfordable stream, or high ridge or deep ravine should therefore be avoided. At theBattle of Dresden(August 26, 1813) the Allies were encamped on the left bank of the Elbe. Their forces were posted on the heights, but the position was cut transversely by a deep ravine, so that the left wing was isolated from the centre and right. This vicious disposition did not escape the penetrating eye of Napoleon, who attacked their isolated wing with superior forces and routed it completely, with the capture of 10,000 prisoners, before any assistance could arrive. The task of creating lateral communications, if none exist, is of the utmost importance, as they enable a commander to achieve the primary object of every military manoeuvre, to meet the enemy with superior forces at the desired point.
(ix)There should be good lines of withdrawal, and these should be horizontal, or only slightly oblique, to {90} the main position, and not parallel with the general alignment. This is a point of the first importance, for if the Lines of Communication lead straight to the rear a force that is overwhelmed by the attack can withdraw to selected positions and towards its base, if it can keep the line intact and prevent its flanks being turned. A wide base, with alternative lines of approach, is of the greatest value, and when there is undue risk of the Lines of Communication to a base being intercepted, an alternative base, with lines of withdrawal thereto from the unexposed flank, is an acceptable safeguard, as the defence can be protracted while the withdrawing force concentrates upon the changed base. Such a change of base was effected by Marshal French during theRetreat from Mons, and amongst many historical examples may be quoted General McClellan's transfer of theArmy of the Potomacfrom the York to the James River in July, 1862, during theSeven Days' Battle around Richmond. General Grant changed his base no fewer than five times during theCampaign in the Wilderness(May, 1864), from Washington to Orange and Alexandria Railroad, then to Fredericksburg on the Rappahannock, then to Port Royal, further east on that river, then to White House on the Pamunkey (a branch of the York River), and finally to the James River. "His army was always well supplied, even his enormous numbers of wounded were carried straight away to the base and thence to Washington, without any difficulty, and he had no obstacles whatever to fight against as regards either feeding his army or keeping up the supply of ammunition" (Henderson). In withdrawing a defeated wing it may even be advantageous to rally the troops at a point distant from the field of battle, and to cause the pursuer, uncertain as to the direction of the retreat, to make detachments which can be overthrown by sudden counter-attacks, or to lure a pursuer from the field where their presence is required, as Grouchy was lured after Napoleon's defeat of the Prussians at Ligny {91} (June 16, 1815). The object of Napoleon's attack on the Allies was the separation of Wellington's Anglo-Belgian force from the Prussian Army under Blücher, and after the defeat of the latter at Ligny the Emperor directed Marshal Grouchy to pursue the Prussians and to drive them eastwards. Grouchy conducted a leisurely pursuit and engaged an insignificant part of the Prussian Army (The Battle of Wavre, June 18-19, 1815), while the main body of the Prussians moved westwards and assisted in the overthrow of Napoleon at Waterloo.
(x)There should be favourable ground and a good line of advance for the Decisive Counter-Attack. In order, therefore, to overthrow the enemy, a position should not be chosen behind an impassable feature which neither side can cross. AtRamillies(May 23, 1706), one wing of the enemy was posted behind a marsh, where it was both unassailable and unable to attack. Marlborough, therefore, ignored that wing entirely, and bringing his whole force against the remaining wing, won easily a decisive victory. The only occasions when an impassable feature is welcome are in the Passive Defence of a small force against overwhelming odds (as was seen in August, 1914, when the Belgians occupied a position behind theRiver Gette), and in the Delaying Action of a Rear-guard fighting for time for the Main Body to get away. In such cases a Decisive Counter-Attack is not contemplated.
OCCUPATION OF A DEFENSIVE POSITION.—The framework of thedefenceis provided by artillery and machine-gun fire; the backbone of theoffenceis the infantry. The Commander willdivide the troopsinto (a)Troops to hold the position, and (b)General Reserve, the golden rule being to make (a) as small as the tactical situation permits in order that (b) may be as large as possible, and its work absolutely decisive. Under no circumstances {92} should the General Reserve be much below half the available force.
Of these two portions, theTroops to hold the positionconsist of infantry occupying a series of mutually supporting tactical strong points, not necessarily continuous, and of irregular alignment so as to cover with the defender's fire not only the ground over which the enemy can advance, but the front and flanks of neighbouring strong points. This line will be strengthened, as and when necessary, by throwing in the supports, and it will be assisted at critical moments by the local reserves, which, coming up unseen, will deliver local counter-attacks on the assaulting enemy, and will thus restore the battle at threatened points by relieving the pressure on the front line. Their work completed they will be rallied and withdrawn again into local reserve, and it is highly important that they should be kept well under control, or their successful efforts may be neutralised by local reserves of the attacking force. AtTalavera(July 27, 1809) a portion of the British force followed up the repulsed French columns too far, and being in turn broken and driven back, was pursued closely by the enemy and retired in disorder to the position. At the battle ofFredericksburg(December 13, 1862) two brigades emerged from the Confederate position and drove Meade's division of the Army of the Potomac out of their lines. But they rushed on with reckless impetuosity and were finally driven back with heavy loss. Local counter-attacks keep alive an offensive spirit in the defenders, exhaust the enemy's powers, draw his reserves into the battle, and thus prepare the opportunity for the Decisive Counter-Attack. The local reserves of flank sections should usually be echeloned in rear of the flank, which can thus be protected at need by determined counter-attacks on the flank of the enveloping force.
The General Reserve is for the Decisive Counter-Attackand is held for this purpose in the hands of the {93} commander of the whole force, in order that it may be used to crush and overthrow the enemy's main attack. The opportunity for this effort is generally obtained only when the enemy has thrown into action his own General Reserve for the decisive attack, and has received a check. A bold and resolute counter-attack at that moment is bound to achieve a decisive success. But the assumption of thegrand offensive should not be confined to the General Reserve alone. Commanders of sections of the defence who are permitted by the local situation to do so, must at once join in the decisive counter-attack, unless express orders to the contrary have been received; and any definite success obtained must be the signal for the whole force to press the enemy with the utmost vigour. This opportunity will be fleeting, and there must be no delay in seizing it. Every preparation must therefore be made in anticipation of the opportunity so that a pre-arranged plan may be put into execution. "To initiate a counter-attack on a large scale without due time for preparation, co-ordination, and movement of troops is to court failure, with heavy casualties and resulting demoralisation" ("Field Service Regulations," vol. ii. (1920)).
That the soul of the defence is the counter-attack was shown at the battle ofSpottsylvania(May 12, 1864). General Hancock's Corps (from Grant's combined armies) had assaulted and captured part of Lee's entrenchments in the Wilderness of Virginia; 20,000 men had assaulted and captured the Salient, taking 4,000 prisoners; they then pressed forward, and sweeping everything before them, drove a wedge right into the Confederate position. "But Lee, recognising the weakness of the Salient, had caused another line of entrenchments to be constructed about half a mile in rear. By this second line the Federals were suddenly brought up. The confusion was very great, the battalions had intermingled in the excitement of the charge, and the officers could neither make their orders {94} heard nor form their men for another rush. Lee threw in his reserves. He made a tremendous counter-attack. Every single battalion he could collect was ordered to attack, and the vigour of the blow was such that the whole of these 20,000 men were driven back beyond the first line of entrenchments, and the Confederates recaptured their first position" (Henderson).
He will select positions for the Artillery, in consultation with the commander of that arm, the objects in view being: to command lines of approach so that the assailant may be shelled and forced to deploy early and so to indicate his plan of attack; to delay the advance; to combine with the infantry in the close defence of the main position; to support local counter-attacks; to destroy hostile batteries by counter-battery work; and to combine eventually in the Decisive Counter-Attack. The increased mobility of guns of the heaviest calibre owing to motor traction, and the increased defensive power of the protective quick-firing small arms, enable guns to be placed close behind the infantry firing line without undue risk of capture.
He will divide the position into sectors, each garrisoned by a distinct unit, under a definite commander. The mutually supporting tactical points (farmsteads, villages, woods, ridges, knolls, etc.) will usually be held in groups, under group commanders, with definite subordinate commanders, and the group commander will probably control the local reserves of that group, with which he can assist any of the units in times of need. The units from which such groups are formed will usually be complete sections.
He will decide the position of the General Reserve. This will be the locality best suited for the advance to the decisive counter-attack, if it is to be delivered from a distance; or near the point where the enemy's decisive attack is expected, if it is intended to hurl the General Reserve into the flank and rear of the enemy's main {95} attack while it is heavily engaged with the troops holding the position. As surprise is essential to success, the position of the General Reserve should be concealed as long as possible. The position of the General Reserve will depend upon the ascertained intentions of the enemy. At theSecond Battle of the Somme(March 21, 1918) the intentions of the German commander were ascertained during the first day's fighting. "As by this time (i.e.the evening of March 21) it had become clear that practically the whole of the enemy's striking force had been committed to this one battle, my plans already referred to for collecting reserves from other parts of the British front were put into immediate execution. By drawing away local reserves and thinning out the front not attacked, it was possible to reinforce the battle by eight divisions before the end of the month" (Sir D. Haig's Dispatches).
He must decide the position, and to some extent the action, of the Cavalry. Before defensive action in a War of Manoeuvre the cavalry have been out on reconnaissance, and during the early stages they have endeavoured to lure the assailants on to a false position. During the battle they will frustrate the efforts of opposing mounted troops, will protect a vulnerable flank, and will assist generally by dismounted fire action. After the victorious counter-attack they will emerge in pursuit. In case of a reverse they will delay the enemy's victorious advance by fire action and by mounted tactics to protect the withdrawing forces from the depredations of hostile cavalry. A position near a flank will usually be occupied.
There have been many examples of protection by cavalry of a force that has been worsted. After theCombat of Roliça(August 17, 1808) General Delaborde retreated by alternate masses, protecting his movements by short, vigorous charges of cavalry. AtChancellorsville(May 3, 1863), and on the first day ofGettysburg(July 1, 1863), a handful of United States {96} cavalry held up the pursuit and staved off disaster. AtKöniggratz(Sadowa), (July 3, 1866), the charges of the Austrian cavalry drove back the Prussian Horse and enabled Benedek's defeated troops to get back in safety. AtRezonville(August 16, 1870) von Bredow's Cavalry Brigade was ordered to charge the French batteries and their infantry escort, in order to give some breathing time for the hard-pressed Prussian infantry. The charge was successful and the time was gained, but as atBalaclava(October 26, 1854) there were few survivors from "Von Bredow's Todtenritt" (death ride). After the battle ofLe Cateau(August 26, 1918) and during theRetreat from Mons, the British cavalry, under General Allenby, effectively held off the enemy and enabled the British troops to move unmolested. During the great German offensive in the spring of 1918 the withdrawal of the troops atCugny(March 24, 1918) was made possible by a brilliant mounted charge by a squadron of the 16th Cavalry Brigade, which broke through the German line, taking over 100 prisoners, and sabring a large number of the enemy. During the retreat in that area units of the 2nd and 3rd Cavalry Divisions proved so effective in delaying the enemy's advance that other units were horsed during the progress of the battle in order to increase the supply of cavalry. "Without the assistance of mounted troops, skilfully handled and gallantly led, the enemy could scarcely have been prevented from breaking through the long and thinly held front of broken and wooded ground before the French reinforcements had had time to arrive. . . . The absence of hostile cavalry at this period was a marked feature of the battle. Had the German command had at their disposal even two or three well-trained cavalry divisions, a wedge might have been driven between the French and British Armies. Their presence could not have failed to have added greatly to the difficulties of our task" (Sir D. Haig's Dispatches).
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He must select a rallying placein rear of the main position from which to recapture the front line, as General Lee recovered the "Salient" in the Wilderness of Virginia.
He must arrange for the reorganisationof his victorious forces and for the pursuit and complete overthrow of the enemy.
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"Surprise consists in the hard fact that the enemy suddenly appears in considerable numbers without his presence having been known to be so near for want of information; and without it being possible to assemble against him for want of protection."—MARSHAL FOCH.
Every commander of a force, however large or small, is responsible for the protection of his command against surprise, and a force can only be regarded as secure from surprise when protection is furnished in every direction from which interference is possible. Detachments are therefore provided by every commander, their duty being to warn him if hostile forces are discovered in the vicinity of such forces, and to gain time, at all risks and at any sacrifice, for the commander of the troops they protect to carry out his plans unimpeded by the enemy. "A mission of protection does not necessarily imply a defensive attitude, it will often be better performed by an offensive" (Marshal Foch). There is the closest connection between Reconnaissance and Protection. It is only by finding out the location, strength and movements of the enemy that a commander can decide how best to protect his troops, and the forces he employs to protect his troops against surprise will very largely prevent the enemy finding out his own strength and dispositions. Detailed and timely information about the enemy and the theatre of operations is a necessary factor in War and the value of the information depends on whether it can reach the authorities in time to be of use.
Facilities for reconnaissance have been enormously increased by the introduction of man-carrying, self-propelled Aircraft. Before their introduction reconnaissance {99} at a distance from the forward troops was limited by the speed and endurance of the cavalryman's horse, and by the skill of the cavalry scout in penetrating the preventive screen of hostile cavalry, and in escaping the net spread out to catch him on the return journey. His radius of operations was comparatively small, that of the aërial observer is practically unlimited, as his machine will carry him over the hostile area, and unless he is driven down by opposing aircraft, or crippled by defensive fire from the ground, he returns in a comparatively short space of time to his base, with his budget of news, and may bring with him a series of photographs.
POSITION WARFARE.—When opposing forces are entrenched at no great distance from one another, photographs taken from the air lead to the discovery of new works from which the intentions of the enemy can be predicted. On the Western Front in the Great War, photographs taken from the air revealed the construction in the German training area of actual sectors of British trenches in facsimile, thus indicating the rehearsal of an attack on a definite part of the line. Hostile aircraft are prevented from carrying out similar observational journeys, the resistance of defending squadrons is overcome, and whenever a favourable target is presented, casualties are caused by bullets and bombs. Observers report all suspicious movements and changes in trench construction, and from photographs taken at daily intervals maps of hostile trenches are constructed and revised. Infantry patrols and raiding parties are sent out by night and by day, and information is gleaned from the uniforms and badges of captured prisoners as to the distribution of hostile troops, while changes in the plan of trenches, in the siting of wire entanglements, or in the emplacements of guns and mortars are duly noted. In addition, troops in observation posts, in or ahead of the front line, in favourable and unsuspected {100} localities, are constantly observing the enemy, and sentries over all posts containing troops are ready at all times of the day and night to alarm the local garrisons. Resistance is afforded by a series of mutually supporting strong points, sufficiently garrisoned by troops who guard against surprise and hold their ground against attack. Entrenchments, with dug-outs and shelters, provide protection from fire, and barbed wire entanglements prevent unbroken rushes by the enemy, and entice him into openings that are swept by rifle and machine-gun fire. Box respirators and other appliances nullify the effects of gas, and camouflage disguises the position of trenches, troops, guns, and dumps, and so screens them from observation and direct bombardment, while it provides unsuspected means of observing the enemy's movements.
MANOEUVRE WARFARE.—In a War of Manoeuvre the steps taken to obtain security against surprise vary with the situation of the troops. Hostile aircraft flying high from the ground are dealt with by counter-attack by armed aeroplanes, but as aërial fighting requires space for manoeuvre hostile machines flying within 3,000 feet of the ground must be dealt with by machine gun, Lewis gun, or concentrated rifle fire, except in cases where it is essential to conceal from the enemy that a certain position or locality is occupied, and where the troops are so well hidden as to escape detection unless they open fire. Movement is easily detected by low-flying aeroplanes, and in fair weather troops can be recognised as hostile or friendly by an observer at 500 feet, while movements of formed bodies on a road are visible at 5,000 feet. Troops remaining stationary in shaded places may easily escape observation, and if small bodies in irregular formation lie face downwards they are difficult to detect, even in the open. When a force is in movement, detachments move with it to afford protection in every direction from which interference {101} is possible; and when a force is at rest, detachments with similar duties secure it from disturbance and keep off attack until it can be met or developed without disadvantage. These phases are dealt with under the headings of "THE ADVANCED GUARD," "FLANK ATTACKS AND FLANK GUARDS," "THE REAR GUARD," and "OUTPOSTS."
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"Fabius, the saviour of Rome, used to say that a commander could notmake a more disgraceful excuse than to plead, 'I never expected it.'It is, in truth, a most shameful reason for any soldier to urge.Imagine everything, expect everything."—SENECA, "De Ira."
Every moving body of troops must be protected by detachments, the force detached to precede the advance being known as an Advanced Guard, and when a body of troops so protected halts, the responsibility for protection during the halts remains with the troops which have been protecting the march until they are relieved, the commander of the Advanced Guard exercising his discretion as to halting at once or moving forward to occupy a position which may be of more tactical advantage.
STRENGTH.—The strength of this Guard depends on the proximity of the enemy, but it must always be strong enough to brush aside slight opposition, so that the advance of the force it is covering may not be delayed by small hostile forces, and to resist the enemy, when encountered in strength, for such time as will enable the force it is covering to prepare to meet or deliver an attack. No general rule as to the numerical strength of an Advanced Guard can be given, as the number of troops required depends almost entirely upon the tactical situation and the country through which the protected force is passing. It should, however, whenever possible be composed of a complete unit or formation under its own commander, and it is found in practice that an Advanced Guard will seldom be less than one-eighth or more than a quarter of the whole {103} force. When a large force is advancing in several columns on parallel roads it will be preceded by a "Strategical Advanced Guard," which protects the front and flanks of all the columns. The "Tactical Advanced Guard" provided by each column may then be reduced in strength.
DISTANCE.—The distance at which it moves ahead of the force it is covering depends upon the nature of the country through which the force is moving, upon the strength of the Main Body, and upon the tactical situation, but it must always be sufficient to enable the Main Body to deploy, to get into battle formation—unmolested by the enemy's artillery, if required to do so. It is clear, therefore, that the larger the Main Body the greater the distance must be, as more time will be required for deployment. The Advanced Guard of a Brigade of infantry, with artillery, would move at a distance of 1 to 2 miles between the Main Guard and the Main Body, with the mounted patrols of the Vanguard 4 to 5 miles ahead of the Main Body. These mounted patrols would discover the presence of an enemy, and with the supports of the Vanguard would feel for his strength and ascertain his dispositions. The Main Guard would either assist in brushing him away or would resist, in the best available position, any attempts to attack the Main Body while the latter formed up for battle.
IN ADVANCES.—Infantry forming part of an Advanced Guard to a force advancing must always act with dash and resolution, but their action must always be regulated by the one motive of complying with the intentions of the commander of the force they are covering. Any action contemplated by the Advanced Guard commander must therefore be considered from the point of view of its effects upon the plans of the commander of the main body, but if these plans are not known, the guiding principle will beto regulate his action solely in the interests {104} of the force he is covering, and by driving in the advanced troops of the enemy he will obtain information which will assist his superior in coming to a decision, without interfering with his liberty of action, whereas hesitation and delay may give the initiative to the enemy. For this reason, a wide turning movement by the Advanced Guard troops is seldom possible, as time is thereby lost and the front of the Main Body is uncovered. "The ruling factor should be the discovery of some tactical locality held by the enemy, the capture of which will compel his whole line to fall back. If this point can be discovered the whole energies of the Advanced Guard should be directed against it alone, and elsewhere a defensive attitude should be adopted, to avoid surprise of or interference with the Main Body" (General R. C. B. Haking).
It must always be assumed that the enemy will have taken all the necessary steps to protect himself and to hamper reconnaissance by an adversary. If, therefore, hostile troops are known to be in a certain locality, opposition must be expected before that locality is reached, and study of the map should enable the Advanced Guard commander to determine the approximate neighbourhood in which opposition may be expected.
IN RETREATS.—While it is clear that a force advancing towards the enemy must always be preceded by an Advanced Guard it must not be forgotten that a force withdrawing from the enemy must also be so protected, even when it is moving in or towards friendly territory. Such a force will not only prevent the Main Body being surprised by an energetic enemy, pursuing swiftly and getting round to attack where he is least expected, but will also prevent the Main Body being delayed by obstacles, and can delay the pursuit by preparing bridges, etc., for demolition, which can be completed by the Rear Guard when the Main Body has passed over {105} them. It can also reconnoitre the route to be followed, so that the Main Body can proceed without delay.
TRAINING.—In formulating any scheme for the exercise of troops in Advanced Guard work all officers and other ranks should be made to understand the nature of the scheme, and should be informed (a) whether the force is advancing or retreating, whether it is moving before or after action with the enemy, and whether it is in a friendly or a hostile country; (b) what is known of the enemy; (c) the direction and objective of the march; (d) the general intentions of the commander of the Main Body; and (e) the general instructions issued to the commander of the Advanced Guard. "Unless such exercises are carried out in a practical manner, young officers and inexperienced N.C.O.'s will get the impression that an Advanced Guard consists merely of a procession of small bodies of infantry, strung out at fixed intervals on a single road. It is of the highest importance that the training should be carried out on the lines that would be adopted in action" (G.H.Q. Circular).