If the leader is filled with high ambition and if he pursues his aims with audacity and strength of will, he will reach them in spite of all obstacles.

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

A prince or general can best demonstrate his genius by managing a campaign exactly to suit his objectives and his resources, doing neither too much nor too little.

The first and most important rule to observe...is to use our entire forces with the utmost energy. The second rule is to concentrate our power as much as possible against that section where the chief blows are to be delivered and to incur disadvantages elsewhere, so that our chances of success may increase at the decisive point. The third rule is never to waste time. Finally, the fourth rule is to follow up our successes with the utmost energy. Only pursuit of the beaten enemy gives the fruits of victory.

Strength of character does not consist solely in having powerful feelings, but in maintaining one's balance in spite of them.

[The cause of inaction in war] ... is the imperfection of human perception and judgment which is more pronounced in war than anywhere else. We hardly know accurately our own situation at any particular moment while the enemy's, which is concealed from us, must be deduced from very little evidence.

In war, while everything is simple, even the simplest thing is difficult. Difficulties accumulate and produce frictions which no one can comprehend who has not seen war.