Without harmony in the State, no military expedition can be undertaken; without harmony in the army, no battle array can be formed.

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

It is a doctrine of war not to assume the enemy will not come, but rather to rely on one's readiness to meet him; not to presume that he will not attack, but rather to make one's self invincible.

Opportunities multiply as they are seized.

Know thy self, know thy enemy.

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

Hence the saying: If you know the enemy and you know yourself, your victory will not stand in doubt; if you now Heaven and you know Earth, you may make your victory complete.