3. A position will be taken with the express intention of there waiting the attack of the enemy—
a. If the disproportion of forces compels us to seek cover from natural obstacles or behind field-works.
b. When the country affords an excellent position for our purpose.
The two modes of defence, 2 and 3, will come more into consideration according as we do not seek the decision itself, but content ourselves with a negative result, and have reason to think that our opponent is wavering and irresolute, and that he will in the end fail to carry out his plans.
4. An entrenched unassailable camp only fulfils the object—
a. If it is situated at an extremely important strategic point.
The character of such a position consists in this, that we cannot be driven out of it; the enemy is therefore obliged to try some other means, that is, to pursue his object without touching this camp, or to blockade it and reduce it by starvation: if it is impossible for him to do this, then the strategic qualities of the position must be very great.
b. If we have reason to expect aid from abroad.
Such was the case with the Saxon army in its position at Pirna. Notwithstanding all that has been said against the measure on account of the ill-success which attended it in this instance, it is perfectly certain that 17,000 Saxons could never have been able to neutralise 40,000 Prussians in any other way. If the Austrians were unable to make better use of the superiority obtained at Lowositz, that only shows the badness of their whole method of war, as well as of their whole military organisation; and there cannot be a doubt that if the Saxons instead of taking post in the camp at Pirna had retired into Bohemia, Frederick the Great would have driven both Austrians and Saxons beyond Prague, and taken that place in the same campaign. Whoever does not admit the value of this advantage, and limits his consideration to the capture of the whole Saxon army, shows himself incapable of making a calculation of all the circumstances in a case of this kind, and without calculation no certain deduction can be obtained.
But as the cases a and b very rarely occur, therefore, the entrenched camp is a measure which requires to be well considered, and which is very seldom suitable in practice. The hope of inspiring the enemy with respect by such a camp, and thus reducing him to a state of complete inactivity, is attended with too much danger, namely, with the danger of being obliged to fight without the possibility of retreat. If Frederick the Great gained his object in this way at Bunzelwitz, we must admire the correct judgment he formed of his adversary, but we must certainly also lay more stress than usual on the resources which he would have found at the last moment to clear a road for the remnants of his army, and also on the irresponsibility of a king.