"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."
{102}