If a supreme decision should lie in their defence and their attack,
they place the assailant in an advantageous situation, for their wide
extent is still more in opposition to all the requirements of a
decisive battle than the direct defence of a river or a mountain range.
Eugene’s lines of Denain, 1712, are an illustration to the point here,
for their loss was quite equal to a complete defeat, but Villars would
hardly have gained such a victory against Eugene in a concentrated
position. If the offensive side does not possess the means required for
a decisive battle, then even lines are treated with respect, that is,
if they are occupied by the main body of an army; for instance, those
of Stollhofen, held by Louis of Baden in the year 1703, were respected
even by Villars. But if they are only held by a secondary force, then
it is merely a question of the strength of the corps which we can spare
for their attack. The resistance in such cases is seldom great, but at
the same time the result of the victory is seldom worth much.
The circumvallation lines of a besieger have a peculiar character, of
which we shall speak in the chapter on the attack of a theatre of war.
All positions of the cordon kind, as, for instance, entrenched lines of
outposts, etc., etc., have always this property, that they can be
easily broken through; but when they are not forced with a view of
going further and bringing on a decision, there is so little to be
gained in general by the attack, that it hardly repays the trouble
expended.