The circumvallation lines of a besieger have a peculiar character, of which we shall speak in the chapter on the attack of a theatre of war.
All positions of the cordon kind, as, for instance, entrenched lines of outposts, etc., etc., have always this property, that they can be easily broken through; but when they are not forced with a view of going further and bringing on a decision, there is so little to be gained in general by the attack, that it hardly repays the trouble expended.
CHAPTER XIII.
Manœuvring
1. We have already touched upon this subject in the thirtieth chapter of the sixth book. It is one which concerns the defence and the attack in common; nevertheless it has always in it something more of the nature of the offensive than the defensive. We shall therefore now examine it more thoroughly.
2. Manœuvring is not only the opposite of executing the offensive by force, by means of great battles; it stands also opposed to every such execution of the offensive as proceeds directly from offensive means, let it be either an operation against the enemy’s communications, or line of retreat, a diversion, etc., etc.
3. If we adhere to the ordinary use of the word, there is in the conception of manœuvring an effect which is first produced, to a certain extent, from nothing, that is, from a state of rest or equilibrium through the mistakes into which the enemy is enticed. It is like the first moves in a game of chess. It is, therefore, a game of evenly-balanced powers, to obtain results from favourable opportunity, and then to use these as an advantage over the enemy.
4. But those interests which, partly as the final object, partly as the principal supports (pivot) of action, must be considered in this matter, are chiefly:—
(a.) The subsistence from which it is our object to cut off the enemy, or to impede his obtaining.
(b.) The junction with other corps.
(c.) The threatening other communications with the interior of the country, or with other armies or corps.