III. The Strategy of War

These are the words of Master Sun:

You should conquer the territory of your enemy without destroying the land. To conquer through destruction is not wise.

It is better to capture an army than to destroy it, and the same is true of a battalion, a regiment, and even a unit of enemy soldiers. It is thus not the hallmark of a great commander to win many battles. Rather, a great commander subjugates the enemy without engaging in battle.

When war is fought, the best course of action is to foil the plans of the enemy. The second best course of action is to stop the enemy from mustering his forces. The third best course of action is to attack the army of the enemy in the field of battle. Finally, the worst course of action is to attack fortified cities.

The main rule is this: Avoid laying siege to fortified cities if this is at all possible. The construction of the equipment needed for a successful siege, such as movable shelters, will take upwards of three months, and the building of ramps up against the city walls will take another three months. An impatient commander will all too easily find himself ordering an attack too early, and like ants his troops will throw themselves against the walls of the fortified city, and the commander will lose a third of his soldiers while leaving the enemy city unscathed. This is how catastrophic an ill-prepared siege can become.

The wise sovereign defeats his enemies without battle, conquers the cities of his enemies without having to besiege them, and overthrows his enemies without waging prolonged campaigns. Thus saving his strength, the wise sovereign may dare to seek to rule the entire Realm, and if he can do so without losing a single man, his triumph will be supreme. This is the strategy of the sovereign who has mastered the art of war.

In tactical maneuvering, the following rules apply:

1. If you outnumber the enemy ten to one, you should surround the enemy.
2. If you outnumber the enemy five to one, you should attack.
3. If you outnumber the enemy two to one, you should attempt to split the army of the enemy in two.
4. If you and your enemy are equally matched, you should lure the enemy into attacking.
5. If you are outnumbered by the enemy, you should avoid him.
6. If the enemy is superior to you in every way, you should run from him.

Even if a small army fights with great honor, it will be captured and defeated by a greater force in the end.

The skillful commander is the bulwark of the state. Thus, if its commander is unmatched in every way, the state will be strong. If, however, its commander is of poor caliber, the state will be weak.

A sovereign can bring misfortune upon his own army in three ways:

1. He can order the army to attack or to retreat without knowing that the army, for whatever reason, cannot obey his command. He will in this way hobble his own army.
2. He can attempt to lead his army in the same way that he governs the state, unaware of the necessities of military discipline. By doing so, he will weaken the discipline of the army.
3. He can meddle in the promotion of officers without being knowledgeable about their merits. Meddling in this way will weaken the resolve of all the officers in the army.

A sovereign who thus hobbles his army and weakens its discipline and resolve will soon find himself targeted by enemies from near and far. This is the origin of the old proverb: "Anarchy within the army is the fountainhead of defeat."

A skillful commander will know these five essential truths of strategy:

1. To win, you must know when to engage in battle and when not to.
2. To win, you must know how to engage with both inferior and superior forces.
3. To win, you must know how to instill a spirit of camaraderie throughout your army.
4. To win, you must know how to wait for an opportunity to arise in which the enemy is unprepared and you yourself are prepared.
5. To win, you must know how to evade your sovereign's meddling in the affairs of your army.

If you know your enemy and yourself, you can fight a hundred battles with no fear of defeat. If you only know yourself but not your enemy, you will suffer as many defeats as you will achieve victories. If you know neither yourself nor your enemy, you will find yourself defeated in every battle.