stating in its purely concrete form. When a Chief of Staff is asked for a
war plan he must not say we will make war in such and such a way because it
was Napoleon's or Moltke's way. He will ask what is the political object of
the war, what are the political conditions, and how much does the question
at issue mean respectively to us and to our adversary. It is these
considerations which determine the nature of the war. This primordial
question settled, he will be in a position to say whether the war is of the
same nature as those in which Napoleon's and Moltke's methods were
successful, or whether it is of another nature in which those methods
failed. He will then design and offer a war plan, not because it has the
hall-mark of this or that great master of war, but because it is one that
has been proved to fit the kind of war in hand. To assume that one method
of conducting war will suit all kinds of war is to fall a victim to
abstract theory, and not to be a prophet of reality, as the narrowest
disciples of the Napoleonic school are inclined to see themselves.

Hence, says Clausewitz, the first, the greatest and most critical decision
upon which the Statesman and the General have to exercise their judgment is
to determine the nature of the war, to be sure they do not mistake it for
something nor seek to make of it something which from its inherent
conditions it can never be. "This," he declares, "is the first and the most
far-reaching of all strategical questions."

The first value, then, of his theory of war is that it gives a clear line
on which we may proceed to determine the nature of a war in which we are
about to engage, and to ensure that we do not try to apply to one nature of
war any particular course of operations simply because they have proved
successful in another nature of war. It is only, he insists, by regarding
war not as an independent thing but as a political instrument that we can
read aright the lessons of history and understand for our practical
guidance how wars must differ in character according to the nature of the
motives and circumstances from which they proceed. This conception, he
claims, is the first ray of light to guide us to a true theory of war and
thereby enable us to classify wars and distinguish them one from another.

Jomini, his great contemporary and rival, though proceeding by a less
philosophical but no less lucid method, entirely endorses this view. A
Swiss soldier of fortune