Many intelligence reports in war are contradictory; even more are false, and most are uncertain.

Friction is the only concept that more or less corresponds to the factors that distinguish real war from war on paper.

The best form of defense is attack.

The object of defense is preservation; and since it is easier to hold ground than to take it, defense is easier than attack. But defense has a passive purpose: preservation; and attack a positive one: conquest.... If defense is the stronger form of war, yet has a negative object, it follows that it should be used only so long as weakness compels, and be abandoned as soon as we are strong enough to pursue a positive object.

We must, therefore, be confident that the general measures we have adopted will produce the results we expect. most important in this connection is the trust which we must have in our lieutenants. consequently, it is important to choose men on whom we can rely and to put aside all other considerations. if we have made appropriate preparations, taking into account all possible misfortunes, so that we shall not be lost immediately if they occur, we must boldly advance into the shadows of uncertainty.

In war more than anywhere else, things do not turn out as we expect.

War is not merely a political act but a real political instrument, a continuation of political intercourse, a carrying out of the same by other means.