Keep their friends close and their enemies closer.

And regulation entails organizational effectiveness, a chain of command, and a structure for logistical support.

Therefore I say: know the enemy and know yourself; in a hundred battles you will never be in peril. When you are ignorant of the enemy but know yourself, your chances of winning or losing are equal. If ignorant both of your enemy and of yourself, you are certain in every battle to be in peril.

It is sufficient to estimate the enemy situation correctly and to concentrate your strength to capture him. There is no more to it than this. He who lacks foresight and underestimates his enemy will surely be captured by him.

Know the enemy, know yourself; your victory will never be endangered. Know the ground, know the weather; your victory will then be total.

The good fighter is able to secure himself against defeat, but cannot make certain of defeating the enemy.

Spies are a most important element in water, because on them depends an army's ability to move.