Now such a position, as before said, must be able to show a front in all directions; and in conformity with the usual extent of tactical positions, if the force is not very large (and a large force would be contrary to the nature of the supposed case) it would take up a very small space, which, in the course of the combat, would be exposed to so many disadvantages that, even if strengthened in every possible way by entrenchments, we could hardly expect to make a successful defence. Such a camp, showing front in every direction, must therefore necessarily have an extent of sides proportionably great; but these sides must likewise be as good as unassailable; to give this requisite strength, notwithstanding the required extension, is not within the compass of the art of field fortification; it is therefore a fundamental condition that such a camp must derive part of its strength from natural impediments of ground which render many places impassable and others difficult to pass. In order, therefore, to be able to apply this defensive means, it is necessary to find such a spot, and when that is wanting, the object cannot be attained merely by field works. These considerations relate more immediately to tactical results in order that we may first establish the existence of this strategic means; we mention as examples for illustration, Pirna, Bunzelwitz, Colberg, Torres Vedras, and Drissa. Now, as respects the strategic properties and effects. The first condition is naturally that the force which occupies this camp shall have its subsistence secured for some time, that is, for as long as we think the camp will be required, and this is only possible when the position has behind it a port, like Colberg and Torres Vedras, or stands in connection with a fortress like Bunzelwitz and Pirna, or has large depôts within itself or in the immediate vicinity, like Drissa.
It is only in the first case that the provisioning can be ensured for any time we please; in the second and third cases, it can only be so for a more or less limited time, so that in this point there is always danger. From this appears how the difficulty of subsistence debars the use of many strong points which otherwise would be suitable for entrenched positions, and, therefore, makes those that are eligible scarce.
In order to ascertain the eligibility of a position of this description, its advantages and defects, we must ask ourselves what the aggressor can do against it.
a. The assailant can pass by this strong position, pursue his enterprise, and watch the position with a greater or less force.
We must here make a distinction between the cases of a position which is occupied by the main body, and one only occupied by an inferior force.
In the first case the passing by the position can only benefit the assailant, if, besides the principal force of the defendant, there is also some other attainable and decisive object of attack, as, for instance, the capture of a fortress or a capital city, etc. But even if there is such an object, he can only follow it if the strength of his base and the direction of his lines of communication are such that he has no cause to fear operations against his strategic flanks.
The conclusions to be drawn from this with respect to the admissibility and eligibility of a strong position for the main body of the defender’s army are, that it is only an advisable position when either the possibility of operating against the strategic flank of the aggressor is so decisive that we may be sure beforehand of being able in that way to keep him at a point where his army can effect nothing, or in a case where there is no object attainable by the aggressor for which the defence need be uneasy. If there is such an object, and the strategic flank of the assailant cannot be seriously menaced, then such position should not be taken up, or if it is it should only be as a feint to see whether the assailant can be imposed upon respecting its value; this is always attended with the danger, in case of failure, of being too late to reach the point which is threatened.
If the strong position is only held by an inferior force, then the aggressor can never be at a loss for a further object of attack, because he has it in the main body itself of the enemy’s army; in this case, therefore, the value of the position is entirely limited to the means which it affords of operating against the enemy’s strategic flank, and depends upon that condition.
b. If the assailant does not venture to pass by a position, he can invest it and reduce it by famine. But this supposes two conditions beforehand: first, that the position is not open in rear, and secondly, that the assailant is sufficiently strong to be able to make such an investment. If these two conditions are united then the assailant’s army certainly would be neutralised for a time by this strong position, but at the same time, the defensive pays the price of this advantage by a loss of his defensive force.
From this, therefore, we deduce that the occupation of such a strong position with the main body is a measure only to be taken,—