A commander in chief ought to say to himself several times a day: If the enemy should appear on my front, on my right, on my left, what would I do? And if the question finds him uncertain, he is not well placed, he is not as he should be, and he should remedy it.
Our faith in others betrays that we would rather have faith in ourselves. Our longing for a friend is our betrayer. And often with our love we want merely to overcome envy. And often we attack and make ourselves enemies, to conceal that we are vulnerable.
Never abandon the possibility of attack. Attack even from a position of inferiority, to disrupt the enemy's plans. This often results in improving one's own position.
So the principles of warfare are: Do not depend on the enemy not coming, but depend on our readiness against him. Do not depend on the enemy not attacking, but depend on our position that cannot be attacked.