This duration is to be regarded to a certain extent as a second
subordinate success. For the conqueror the combat can never be finished
too quickly, for the vanquished it can never last too long. A speedy
victory indicates a higher power of victory, a tardy decision is, on the
side of the defeated, some compensation for the loss.

This is in general true, but it acquires a practical importance in its
application to those combats, the object of which is a relative defence.

Here the whole success often lies in the mere duration. This is the
reason why we have included it amongst the strategic elements.

The duration of a combat is necessarily bound up with its essential
relations. These relations are, absolute magnitude of force, relation
of force and of the different arms mutually, and nature of the country.
Twenty thousand men do not wear themselves out upon one another as
quickly as two thousand: we cannot resist an enemy double or three times
our strength as long as one of the same strength; a cavalry combat is
decided sooner than an infantry combat; and a combat between infantry
only, quicker than if there is artillery(*) as well; in hills and
forests we cannot advance as quickly as on a level country; all this is
clear enough.

(*) The increase in the relative range of artillery and the
introduction of shrapnel has altogether modified this
conclusion.

From this it follows, therefore, that strength, relation of the three
arms, and position, must be considered if the combat is to fulfil an
object by its duration; but to set up this rule was of less importance
to us in our present considerations than to connect with it at once the
chief results which experience gives us on the subject.

Even the resistance of an ordinary Division of 8000 to 10,000 men of
all arms even opposed to an enemy considerably superior in numbers,
will last several hours, if the advantages of country are not too
preponderating, and if the enemy is only a little, or not at all,
superior in numbers, the combat will last half a day. A Corps of three
or four Divisions will prolong it to double the time; an Army of 80,000
or 100,000 to three or four times. Therefore the masses may be left to
themselves for that length of time, and no separate combat takes place
if within that time other forces can be brought up, whose co-operation
mingles then at once into one stream with the results of the combat
which has taken place.

These calculations are the result of experience; but it is important to
us at the same time to characterise more particularly the moment of the
decision, and consequently the termination.