With respect to the cutting off an enemy’s retreat, we must not be overconfident in this respect either of the consequences of threatening or closing the enemy’s lines of retreat, as recent experience has shown that, when troops are good and their leader resolute, it is more difficult to make them prisoners, than it is for them to cut their way through the force opposed to them.
The means of shortening and protecting long lines of communication are very limited. The seizure of some fortresses adjacent to the position taken up by the army, and on the roads leading to the rear—or in the event of there being no fortresses in the country, the construction of temporary defences at suitable points—the kind treatment of the people of the country, strict discipline on the military roads, good police, and active measures to improve the roads, are the only means by which the evil may be diminished, but it is one which can never be entirely removed.
Furthermore, what we said when treating of the question of subsistence with respect to the roads which the army should chose by preference, applies also particularly to lines of communication. The best lines of communication are roads leading through the most flourishing towns and the most important provinces; they ought to be preferred, even if considerably longer, and in most cases they exercise an important influence on the definitive disposition of the army.