If you know both yourself and your enemy, you can win a hundred battles without a single loss.

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

If an enemy has alliances, the problem is grave and the enemy's position strong; if he has no alliances, the problem is minor and the enemy's position weak.

Without local guides, your enemy employs the land as a weapon against you.

Of old the expert in battle would first make himself invincible and then wait for his enemy to expose his vulnerability.

Spies cannot be usefully employed without a certain intuitive sagacity; They cannot be properly managed without benevolence and straightforwardness; Without subtle ingenuity of mind, one cannot make certain of the truth of their reports; Be subtle! be subtle! and use your spies for every kind of warfare; If a secret piece of news is divulged by a spy before the time is ripe, he must be put to death together with the man to whom the secret was told.

Those who would wage war, should first eliminate all domestic enemies before proceeding to attack the external foe.