Know the enemy and know yourself.

Hence the saying: The enlightened ruler lays his plans well ahead; the good general cultivates his resources.

Subtle and insubstantial, the expert leaves no trace; divinely mysterious, he is inaudible. Thus he is master of his enemy's fate.

It is the business of a general to be quiet and thus ensure secrecy; upright and just, and thus maintain order.

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

It is essential to seek out enemy agents who have come to conduct espionage against you and to bribe them to serve you. Give them instructions and care for them. Thus doubled agents are recruited and used.

Go into emptiness, strike voids, bypass what he defends hit him where he does not expect you.