their operations to the security of certain important places, while the
other directed their whole attention to the siege and capture of these
places. But Carnot and Napoleon changed this system, at the same time
with the system of tactics, or rather, returned from it to the old and
true system of strategic operations. Some men, looking merely at the
fact that a _change_ was made, but without examining the _character_ of
that change, have rushed headlong to the conclusion that fortified
places are now utterly useless in war, military success depending
entirely upon a good system of marches.

On this subject, General Jomini, the great military historian of the
wars of the French Revolution, remarks that "we should depend entirely
upon neither organized masses, nor upon material obstacles, whether
natural or artificial. To follow exclusively either of these systems
would be equally absurd. The true science of war consists in choosing a
just medium between the two extremes. The wars of Napoleon demonstrated
the great truth, that distance can protect no country from invasion, but
that a state, to be secure, must have a good system of fortresses, and a
good system of military reserves and military institutions."

In all military operations _time_ is of vast importance. If a single
division of an army can be retarded for a few hours only, it not
unfrequently decides the fate of the campaign. Had the approach of
Blucher been delayed for a few hours, Napoleon must have been victorious
at the battle of Waterloo. An equilibrium can seldom be sustained for
more than six or seven hours between forces on the field of battle; but
in this instance, the state of the ground rendered the movements so
slow as to prolong the battle for about twelve hours; thus enabling the
allies to effect a concentration in time to save Wellington.