_Diplomacy in its relation to War_.
Although this branch is more naturally and intimately connected with the
profession of a statesman than with that of a soldier, it cannot be
denied that, if it be useless to a subordinate general, it is
indispensable to every general commanding an army: it enters into all
the combinations which may lead to a war, and has a connection with the
various operations to be undertaken in this war; and, in this view, it
should have a place in a work like this.

To recapitulate, the art of war consists of six distinct parts:--

1. Statesmanship in its relation to war.

2. Strategy, or the art of properly directing masses upon the theater of
war, either for defense or for invasion.

3. Grand Tactics.

4. Logistics, or the art of moving armies.

5. Engineering,--the attack and defense of fortifications.

6. Minor Tactics.

It is proposed to analyze the principal combinations of the first four
branches, omitting the consideration of tactics and of the art of
engineering.

Familiarity with all these parts is not essential in order to be a good
infantry, cavalry, or artillery officer; but for a general, or for a
staff officer, this knowledge is indispensable.

CHAPTER I.

STATESMANSHIP IN ITS RELATION TO WAR.

Under this head are included those considerations from which a statesman
concludes whether a war is proper, opportune, or indispensable, and
determines the various operations necessary to attain the object of the
war.

A government goes to war,--

To reclaim certain rights or to defend them;

To protect and maintain the great interests of the state, as commerce,
manufactures, or agriculture;

To uphold neighboring states whose existence is necessary either for the
safety of the government or the balance of power;

To fulfill the obligations of offensive and defensive alliances;

To propagate political or religious theories, to crush them out, or to
defend them;

To increase the influence and power of the state by acquisitions of
territory;

To defend the threatened independence of the state;

To avenge insulted honor; or,

From a mania for conquest.

It may be remarked that these different kinds of war influence in some
degree the nature and extent of the efforts and operations necessary for
the proposed end. The party who has provoked the war may be reduced to
the defensive, and the party assailed may assume the offensive; and
there may be other circu