Generally in warfare, keeping a nation intact is best, destroying a nation second best; keeping an army intact is best, destroying an army second best; keeping a battalion intact is best, destroying a battalion second best; keeping a company intact is best, destroying a company second best; keeping a squad intact is best, destroying a squad second best.
Therefore, to gain a hundred victories in a hundred battles is not the highest excellence; to subjugate the enemy’s army without doing battle is the highest of excellence.
Therefore, the best warfare strategy is to attack the enemy’s plans, next is to attack alliances, next is to attack the army, and the worst is to attack a walled city.
Laying siege to a city is only done when other options are not available.
To build large protective shields, armored wagons, and make ready the necessary arms and equipment will require at least three months.
To build earthen mounds against the walls will require another three months.
If the general cannot control his temper and sends troops to swarm the walls, one third of them will be killed, and the city will still not be taken.
This is the kind of calamity when laying siege to a walled city.
Therefore, one who is skilled in warfare principles subdues the enemy without doing battle, takes the enemy’s walled city without attacking, and overthrows the enemy quickly, without protracted warfare.
His aim must be to take All-Under-Heaven intact.
Therefore, weapons will not be blunted, and gains will be intact.
These are the principles of planning attacks.
Generally in warfare:
- If ten times the enemy’s strength, surround them;
- If five times, attack them;
- If double, divide them;
- If equal, be able to fight them;
- If fewer, be able to evade them;
- If weaker, be able to avoid them.
Therefore, a smaller army that is inflexible will be captured by a larger one.
A general is the safeguard of the nation.
When this support is in place, the nation will certainly be strong.
When this support is not in place, the nation will certainly not be strong.
There are three ways the ruler can bring difficulty to the army:
- To order an advance when not realizing the army is in no position to advance, or to order a withdrawal when not realizing the army is in no position to withdraw.
This is called entangling the army.
- By not knowing the army’s matters, and administering the army the same as administering civil matters, the officers and troops will be confused.
- By not knowing the army’s calculations, and taking command of the army, the officers and troops will be hesitant.
- When the army is confused and hesitant, the neighboring rulers will take advantage.
This is called a confused and hesitant army leading another to victory.
Therefore, there are five factors of knowing who will win:
- One who knows when he can fight, and when he cannot fight, will be victorious;
- One who knows how to use both large and small forces will be victorious;
- One who knows how to unite upper and lower ranks in purpose will be victorious;
- One who is prepared and waits for the unprepared will be victorious;
- One whose general is able and is not interfered by the ruler will be victorious.
These five factors are the way to know who will win.
Therefore I say:
- One who knows the enemy and knows himself will not be in danger in a hundred battles.
- One who does not know the enemy but knows himself will sometimes win, sometimes lose.
- One who does not know the enemy and does not know himself will be in danger in every battle.