On War
Clausewitz (1827)
The manner of conducting a combat at night, and what concerns the details of its course, is a tactical subject; we only examine it here so far as in its totality it appears as a special strategic means.
Fundamentally every night attack is only a more vehement form of surprise. Now at the first look of the thing such an attack appears quite pre-eminently advantageous, for we suppose the enemy to be taken by surprise, the assailant naturally to be prepared for everything which can happen. What an inequality! Imagination paints to itself a picture of the most complete confusion on the one side, and on the other side the assailant only occupied in reaping the fruits of his advantage. Hence the constant creation of schemes for night attacks by those who have not to lead them, and have no responsibility, whilst these attacks seldom take place in reality.
These ideal schemes are all based on the hypothesis that the assailant knows the arrangements of the defender because they have been made and announced beforehand, and could not escape notice in his reconnaissances, and inquiries; that on the other hand, the measures of the assailant, being only taken at the moment of execution, cannot be known to the enemy. But the last of these is not always quite the case, and still less is the first. If we are not so near the enemy as to have him completely under our eye, as the Austrians had Frederick the Great before the battle of Hochkirch (1758), then all that we know of his position must always be imperfect, as it is obtained by reconnaissances, patrols, information from prisoners, and spies, sources on which no firm reliance can be placed because intelligence thus obtained is always more or less of an old date, and the position of the enemy may have been altered in the meantime. Moreover, with the tactics and mode of encampment of former times it was much easier than it is now to examine the position of the enemy. A line of tents is much easier to distinguish than a line of huts or a bivouac; and an encampment on a line of front, fully and regularly drawn out, also easier than one of Divisions formed in columns, the mode often used at present. We may have the ground on which a Division bivouacs in that manner completely under our eye, and yet not be able to arrive at any accurate idea.
But the position again is not all that we want to know the measures which the defender may take in the course of the combat are just as important, and do not by any means consist in mere random shots. These measures also make night attacks more difficult in modern Wars than formerly, because they have in these campaigns an advantage over those already taken. In our combats the position of the defender is more temporary than definitive, and on that account the defender is better able to surprise his adversary with unexpected blows, than he could formerly.[*]
[*] All these difficulties obviously become increased as the power of the weapons in use tends to keep the combatants further apart.--editor.
Therefore what the assailant knows of the defensive previous to a night attack, is seldom or never sufficient to supply the want of direct observation.
But the defender has on his side another small advantage as well, which is that he is more at home than the assailant, on the ground which forms his position, and therefore, like the inhabitant of a room, will find his way about it in the dark with more ease than a stranger. He knows better where to find each part of his force, and therefore can more readily get at it than is the case with his adversary.
From this it follows, that the assailant in a combat at night feels the want of his eyes just as much as the defender, and that therefore, only particular reasons can make a night attack advisable.
Now these reasons arise mostly in connection with subordinate parts of an Army, rarely with the Army itself; it follows that a night attack also as a rule can only take place with secondary combats, and seldom with great battles.
We may attack a portion of the enemy’s Army with a very superior force, consequently enveloping it with a view either to take the whole, or to inflict very severe loss on it by an unequal combat, provided that other circumstances are in our favour. But such a scheme can never succeed except by a great surprise, because no fractional part of the enemy’s Army would engage in such an unequal combat, but would retire instead. But a surprise on an important scale except in rare instances in a very close country, can only be effected at night. If therefore we wish to gain such an advantage as this from the faulty disposition of a portion of the enemy’s Army, then we must make use of the night, at all events, to finish the preliminary part even if the combat itself should not open till towards daybreak. This is therefore what takes place in all the little enterprises by night against outposts, and other small bodies, the main point being invariably through superior numbers, and getting round his position, to entangle him unexpectedly in such a disadvantageous combat, that he cannot disengage himself without great loss.
The larger the body attacked the more difficult the undertaking, because a strong force has greater resources within itself to maintain the fight long enough for help to arrive.
On that account the whole of the enemy’s Army can never in ordinary cases be the object of such an attack for although it has no assistance to expect from any quarter outside itself, still, it contains within itself sufficient means of repelling attacks from several sides particularly in our day, when every one from the commencement is prepared for this very usual form of attack. Whether the enemy can attack us on several sides with success depends generally on conditions quite different from that of its being done unexpectedly; without entering here into the nature of these conditions, we confine ourselves to observing, that with turning an enemy, great results, as well as great dangers are connected; that therefore, if we set aside special circumstances, nothing justifies it but a great superiority, just such as we should use against a fractional part of the enemy’s Army.
But the turning and surrounding a small fraction of the enemy, and particularly in the darkness of night, is also more practicable for this reason, that whatever we stake upon it, and however superior the force used may be, still probably it constitutes only a limited portion of our Army, and we can sooner stake that than the whole on the risk of a great venture. Besides, the greater part or perhaps the whole serves as a support and rallying-point for the portion risked, which again very much diminishes the danger of the enterprise.
Not only the risk, but the difficulty of execution as well confines night enterprises to small bodies. As surprise is the real essence of them so also stealthy approach is the chief condition of execution: but this is more easily done with small bodies than with large, and for the columns of a whole Army is seldom practicable. For this reason such enterprises are in general only directed against single outposts, and can only be feasible against greater bodies if they are without sufficient outposts, like Frederick the Great at Hochkirch.[*] This will happen seldomer in future to Armies themselves than to minor divisions.
[*] October 14, 1758.
In recent times, when War has been carried on with so much more rapidity and vigour, it has in consequence often happened that Armies have encamped very close to each other, without having a very strong system of outposts, because those circumstances have generally occurred just at the crisis which precedes a great decision.
But then at such times the readiness for battle on both sides is also more perfect; on the other hand, in former Wars it was a frequent practice for armies to take up camps in sight of each other, when they had no other object but that of mutually holding each other in check, consequently for a longer period. How often Frederick the Great stood for weeks so near to the Austrians, that the two might have exchanged cannon shots with each other.
But these practices, certainly more favourable to night attacks, have been discontinued in later days; and armies being now no longer in regard to subsistence and requirements for encampment, such independent bodies complete in themselves, find it necessary to keep usually a day’s march between themselves and the enemy. If we now keep in view especially the night attack of an army, it follows that sufficient motives for it can seldom occur, and that they fall under one or other of the following classes.
1. An unusual degree of carelessness or audacity which very rarely occurs, and when it does is compensated for by a great superiority in moral force.
2. A panic in the enemy’s army, or generally such a degree of superiority in moral force on our side, that this is sufficient to supply the place of guidance in action.
3. Cutting through an enemy’s army of superior force, which keeps us enveloped, because in this all depends on surprise. and the object of merely making a passage by force, allows a much greater concentration of forces.
4. Finally, in desperate cases, when our forces have such a disproportion to the enemy’s, that we see no possibility of success, except through extraordinary daring.
But in all these cases there is still the condition that the enemy’s army is under our eyes, and protected by no advance-guard.
As for the rest, most night combats are so conducted as to end with daylight, so that only the approach and the first attack are made under cover of darkness, because the assailant in that manner can better profit by the consequences of the state of confusion into which he throws his adversary; and combats of this description which do not commence until daybreak, in which the night therefore is only made use of to approach, are not to be counted as night combats.