two things--their geographical situation, and their respective weight
in arms. For before we can judge the chances of two opponents in war,
we have to know how they stand physically one to the other upon the
surface of the earth, or we cannot judge how one will attack the
other, or how each will defend itself against the other. And we must
further be able to judge the numbers engaged both at the beginning of
the struggle and arriving in reinforcement as the struggle proceeds,
because upon those numbers will mainly depend the final result.

Having acquired these two fundamental pieces of information, we must
acquire a third, which is _the theories of war_ held upon either side,
and some summary showing which of these theories turned out in
practice to be right, and which wrong.

For, after a long peace, the fortune of the next war largely depends
upon which of various guesses as to the many changes that have taken
place in warfare and in weapons will be best supported by practice,
and what way of using new weapons will prove the most effective. Until
the test of war is applied, all this remains guess-work; but under the
conditions of war it ceases to be guess-work, and becomes either
corroborated by experience or exploded, as the case may be. And of two
opponents after a long peace, that one which has had the most
foresight and has guessed best what the effect of changes in armament
and the rest will effect in practice is that one who has the best
chance of victory.

We are going, then, in this Second Part, of the little book, to see,
first, the geographical position of the belligerents; secondly, their
effective numbers; and, thirdly, what theories of war each held, and
how far each was right or wrong.