Sun-tzu

If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle.

All warfare is based on deception. There is no place where espionage is not used. Offer the enemy bait to lure him.

A military operation involves deception. Even though you are competent, appear to be incompetent. Though effective, appear to be ineffective.

If you are near the enemy, make him believe you are far from him.
If you are far from the enemy, make him believe you are near.

Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win.

War is based on deception.

Appraise war in terms of the fundamental factors. The first of these factors is moral influence.

The best victory is when the opponent surrenders of its own accord before there are any actual hostilities...It is best to win without fighting.

Keep your friends close, and your enemies closer.

- Sun-tzu