ert to improve all opportunities of assailing the weak points of
the enemy. This plan of war may be called the defensive-offensive, and
may have strategical as well as tactical advantages.. It combines the
advantages of both systems; for one who awaits his adversary upon a
prepared field, with all his own resources in hand, surrounded by all
the advantages of being on his own ground, can with hope of success take
the initiative, and is fully able to judge when and where to strike.

During the first three campaigns of the Seven Years' War Frederick was
the assailant; in the remaining four his conduct was a perfect model of
the defensive-offensive. He was, however, wonderfully aided in this by
his adversaries, who allowed him all the time he desired, and many
opportunities of taking the offensive with success. Wellington's course
was mainly the same in Portugal, Spain, and Belgium, and it was the most
suitable in his circumstances. It seems plain that one of the greatest
talents of a general is to know how to use (it may be alternately) these
two systems, and particularly to be able to take the initiative during
the progress of a defensive war.

ARTICLE XVII.

Of the Theater of Operations.

The theater of a war comprises all the territory upon which the parties
may assail each other, whether it belong to themselves, their allies, or
to weaker states who may be drawn into the war through fear or interest.
When the war is also maritime, the theater may embrace both
hemispheres,--as has happened in contests between France and England
since the time of Louis XIV. The theater of a war may thus be undefined,
and must, not be confounded with the theater of operations of one or the
other army. The theater of a continental war between France and Austria
may be confined to Italy, or may, in addition, comprise Germany if the
German States take part therein.

Armies may act in concert or separately: in the first case the whole
theater of operations may be considered as a single field upon which
strategy directs the armies for the attainment of a definite end. In the
second case each army will have its own independent theater of
operations. The _theater of operations_ of an army embraces all the
territory it may desire to invade and all that it may be necessary to
defend. If the army operates independently, it should not attempt any
maneuver beyond its own theater, (though it should leave it if it be in
danger of being su