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 defensive _rôle_ is 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.