(vi) _There should be good artillery positions_ to 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 depth_ to 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 communication_ in 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 the _Battle 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 a.s.sistance 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 the _Retreat from Mons_, and amongst many historical examples may be quoted General McClellan's transfer of the _Army of the Potomac_ from the York to the James River in July, 1862, during the _Seven Days' Battle around Richmond_.

General Grant changed his base no fewer than five times during the _Campaign 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 Blucher, 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 a.s.sisted 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 impa.s.sable feature which neither side can cross. At _Ramillies_ (May 23, 1706), one wing of the enemy was posted behind a marsh, where it was both una.s.sailable 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 impa.s.sable feature is welcome are in the Pa.s.sive Defence of a small force against overwhelming odds (as was seen in August, 1914, when the Belgians occupied a position behind the _River 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 the _defence_ is provided by artillery and machine-gun fire; the backbone of the _offence_ is the infantry. The Commander will _divide the troops_ into (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 circ.u.mstances {92} should the General Reserve be much below half the available force.

Of these two portions, the _Troops to hold the position_ consist 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 a.s.sisted at critical moments by the local reserves, which, coming up unseen, will deliver local counter-attacks on the a.s.saulting 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. At _Talavera_ (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 of _Fredericksburg_ (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-Attack_ and 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 a.s.sumption of the _grand 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 antic.i.p.ation 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 of _Spottsylvania_ (May 12, 1864). General Hanc.o.c.k's Corps (from Grant's combined armies) had a.s.saulted and captured part of Lee's entrenchments in the Wilderness of Virginia; 20,000 men had a.s.saulted 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 a.s.sailant may be sh.e.l.led 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 a.s.sist 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 the _Second 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 a.s.sailants on to a false position. During the battle they will frustrate the efforts of opposing mounted troops, will protect a vulnerable flank, and will a.s.sist 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 the _Combat of Rolica_ (August 17, 1808) General Delaborde retreated by alternate ma.s.ses, protecting his movements by short, vigorous charges of cavalry. At _Chancellorsville_ (May 3, 1863), and on the first day of _Gettysburg_ (July 1, 1863), a handful of United States {96} cavalry held up the pursuit and staved off disaster. At _Koniggratz_ (_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. At _Rezonville_ (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 at _Balaclava_ (October 26, 1854) there were few survivors from "Von Bredow's Todtenritt" (death ride). After the battle of _Le Cateau_ (August 26, 1918) and during the _Retreat 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 at _Cugny_ (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 a.s.sistance 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).

{97}

_He must select a rallying place_ in 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 reorganisation_ of his victorious forces and for the pursuit and complete overthrow of the enemy.

{98}

PROTECTION AND RECONNAISSANCE

"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 a.s.semble 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 att.i.tude, 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 aerial 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 s.p.a.ce 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 aerial fighting requires s.p.a.ce 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."

{102}

THE ADVANCED GUARD

"Fabius, the saviour of Rome, used to say that a commander could not make 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 pa.s.sing.

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 a.s.sist 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 be _to 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 a.s.sist 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 att.i.tude should be adopted, to avoid surprise of or interference with the Main Body"

(General R. C. B. Haking).

It must always be a.s.sumed 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 pa.s.sed 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).

TACTICAL PRINCIPLES.--"Speed of advance is the first consideration when not in contact with the enemy. Hence an Advanced Guard will move on a narrow front along roads and other channels of communication, with such distances between advanced and supporting bodies as to avoid possibility of surprise. When in contact with, or in the vicinity of, the enemy, security and speed of advance are equal considerations.

Hence the Advanced Guard should move by bounds on a broad fighting front across country" ("Infantry Training, 1921").