It is therefore of the highest importance that the enemy shall be prevented from gaining observation as to the conduct of the reserve, in order that its presence may eventually come as a surprise to him. Hostile patrols must be attacked with remorseless energy wherever seen, and, if possible, put out of action. Those look-out points, on the other hand, from which observation can be made of the enemy must be occupied early in the fight.
The cavalry will, as a rule, only undertake a completely passive defence, where the object of the fight is to hold the crossing over some obstacle, to defend isolated localities, or to gain time. In such a case the question is one of the obstinate defence of a definite object, sometimes perhaps, also, of a retirement from one point to another. Such an operation, however, is always difficult to carry out on account of the led horses, and should only be attempted in very favorable country. It demands that the fight shall be broken off—always a difficult matter, and, to cavalry encumbered by their led horses, one of considerable danger. The horses certainly render it possible, by making a proper use of the ground, to withdraw more rapidly than could infantry in the same case. On the other hand, however, they tie the dismounted troops down to a definite direction of retreat, and remounting, when pressed by the enemy, is always a critical matter.
4. Breaking off the Fight, Retreat, and Pursuit
When it becomes apparent during the course of a fight that success cannot ensue, the commander must decide in good time whether he will carry the engagement through or break it off. To choose the right moment for the latter operation is generally extraordinarily difficult, even when it has been planned from the commencement. To make the necessary dispositions, also, demands great tactical skill. To continue the fight with determination, perhaps till nightfall, will often cost no greater sacrifice than the breaking off of the engagement and the attendant retreat.
Generally speaking, such engagements will only be those which are fought out on foot. The more open the country, the closer the enemy, and the greater the number of troops which have already been thrown into the fighting-line, so much the more difficult will it usually be to break off the fight. The circumstance also as to whether the led horses are mobile or immobile, and their position, will naturally influence the decision. On the other hand, it is easier to extricate the force after some success has been gained; whether it be that a hostile attack has been repulsed, or that our own troops have made a successful counter-stroke. History teaches us that at such moments there is generally a lull, during which the opponent is obliged to bring up fresh troops or to make fresh tactical dispositions.
Even under such favourable conditions, however, it will generally be impossible to break loose from the enemy without suffering heavy loss.
In defence, if the ground is especially favourable, it will certainly be possible at times to extricate a force without considerable loss. If it can rapidly withdraw from the firing-line and retire covered from pursuing fire, the whole force may under certain circumstances simultaneously evacuate a position, that is to say, if the enemy is still so far distant that he is unable to employ pursuing fire until the defender has reached a place of safety. How seldom, however, will such be the case! Small detachments will generally have to be sacrificed to secure the retreat of the main body. This means that various especially strong supporting points in the position will be occupied, and the force will withdraw under cover of them.
Military history offers us repeated examples where the attacker makes desperate endeavours to overpower such points, and in so doing forgets to pursue the withdrawing masses of the defender's troops. This, for example, was the part played at the battle of Weissenburg by Geisberg Castle and Schafbusch, and the château with its enclosed park at the battle of Coulmiers. Under cover of these points, against which all the efforts of the French were concentrated, the defenders were able in both cases to withdraw so slightly molested that even touch with them was completely lost.
The defence of such supporting points, which must be conducted with the utmost obstinacy, frequently ends in capture, but the end gained is worth the sacrifice. If the endeavour is made to withdraw the whole line of defence simultaneously under circumstances where it is possible for the attacker to bring to bear an effective pursuing fire from the captured position, loss will generally be much greater than that which would be deliberately incurred in arresting the pursuit.
The conditions are similar in attack. At manœuvres certainly we see the attacker when repulsed turn about, and, in a continuous retreat, lay himself open to a pursuing fire, which would mean absolute destruction. I do not think such a manœuvre possible in reality. As the advance has been by stages, so must be the retreat. But, whereas in the advance it was a matter of pressing forward on a wide connected front, in order to hold the whole of the enemy's position under fire, and not of massing together where cover could be obtained, the exact contrary is the case in retreat, and the troops must seek any cover that will shelter them from the fire of the pursuit. Various strong points in the attack which have already been taken and occupied must be obstinately held during the retirement, and from them a heavy fire poured into the pursuit to bring it to a standstill. Care should be taken, even during an advance, to keep such places well supplied with ammunition, which can either be taken forward to the captured position or be at the disposal of the retiring troops.