by our troops.
Now in such a case as is here supposed, especially if attended with other favourable circumstances, it is possible to act against the communications of an army, although their direction is perpendicular to the position of that army; for the detachments employed for the purpose do not then require to fall back always on their own army, because being in their own country they are safe enough if they only make their escape.
We have, therefore, now ascertained that—
- A considerable length,
- An oblique direction,
- An enemy’s province,
are the principal circumstances under which the lines of communication of an army may be interrupted by a relatively small proportion of armed forces on the side of the enemy; in order to make this interruption effectual, a fourth condition is still requisite, which is a certain duration of time. Respecting this point, we beg attention to what has been said in the fifteenth chapter of the fifth book.