support and maintain this system. But if these commissaries, commandants of stations, police, fieldposts, and the rest of the apparatus of administration, were sent to some distant road upon which the army had not been seen, the inhabitants then would look upon such measures as a burden which they would gladly get rid of, and if the most complete defeats and catastrophes had not previously spread terror throughout the land, the probability is that these functionaries would be treated as enemies, and driven away with very rough usage. Therefore in the first place it would be necessary to establish garrisons to subjugate the new line, and these garrisons would require to be of more than ordinary strength, and still there would always be a danger of the inhabitants rising and attempting to overpower them. In short, an army marching into an enemy’s country is destitute of the mechanism through which obedience is rendered; it has to institute its officials into their places, which can only be done by a strong hand, and this cannot be effected thoroughly without sacrifices and difficulties, nor is it the work of a moment—From this it follows that a change of the system of communication is much less easy of accomplishment in an enemy’s country than in our own, where it is at least possible; and it also follows that the army is more restricted in its movements, and must be much more sensitive about any demonstrations against its communications.
But the choice and organisation of lines of communication is from the very commencement subject also to a number of conditions by which it is restricted. Not only must they be in a general sense good high roads, but they will be the more serviceable the wider they are, the more populous and wealthy towns they pass through, the more strong places there are which afford them protection. Rivers, also, as means of water communication, and bridges as points of passage, have a decisive weight in the choice. It follows from this that the situation of a line of communication, and consequently the road by which an army proceeds to commence the offensive, is only a matter of free choice up to a certain point, its situation being dependent on certain geographical relations.