The main point of this chapter is that one should only go into battle when one has the advantage. It closes with the famous dictum about knowing oneself and one’s opponent.
Master Sun said,
The method of waging war holds that it is always best
to take1 the opposing country intact,2
whereas destroying the opposing country is next best.
Taking an opposing army intact is best,
whereas destroying it is next best.
Taking an opposing regiment intact is best,
whereas destroying it is next best.
Taking an opposing company intact is best,
whereas destroying it is next best.
Taking an opposing squad3 intact is best,
whereas destroying it is next best.
For this reason,
being victorious a hundred times in a hundred battles is not the most excellent approach. Causing the enemy forces to submit without a battle is the most excellent approach.4
Therefore,
the most superior stratagem in warfare is to stymie the enemy’s plans;
the next best is to stymie his alliances;
the next best is to stymie his troops;
the worst is to attack his walled cities
The method of attacking walled cities should be resorted to only when there is no other option.
To attack a walled city, it is necessary to construct mantlets and assault wagons,5 and to make ready siege machines, which require three months to complete; then mounds of earth must be piled up against the walls, again requiring three months to finish. Unable to overcome his anger, the general sends his troops to clamber up the walls like ants. A third of his troops are killed, and still the city does not fall. This is the disaster that results from attacking walled cities.6
Therefore,
he who is skilled at waging war causes his opponent’s soldiers to submit without having to fight a battle, causes his opponent’s cities to fall without having to attack them, and destroys his opponent’s kingdom without having to engage in prolonged war. Instead, with a comprehensive strategy, he contends before all under heaven.
Therefore,
his soldiers are not worn down, yet his advantages are preserved intact. This is the method of attack by stratagem.7
Therefore,
the method of waging war is
to encircle the enemy when one has ten times the number of his forces,
to attack the enemy when one has five times the number of his forces,
to divide the enemy when one has twice the number of his forces,
to battle the enemy when one’s forces are equal to his.8
Therefore,
he who stubbornly persists though his forces are fewer
will be captured by an enemy whose forces are more numerous.
Now, the general is the buttress of the kingdom. When the buttress is solid, the kingdom will surely be strong; when the buttress is defective, the kingdom will surely be weak.
Therefore,
there are three respects in which the army may be troubled by the ruler. When the ruler does not understand that the army cannot advance, yet he orders it to advance, or when the ruler does not understand that the army cannot retreat, yet he orders it to retreat, this is called “hobbling the army.”
When the ruler does not understand the affairs of the triple army,9 yet participates in its administration, the officers and troops will be confused. When the ruler does not understand the expediency of the triple army, yet participates in its supervision, the officers and troops will be suspicious. When the triple army is both confused and suspicious, difficulties from the feudal lords will have arrived. This is called bringing chaos to one’s own army and inviting the victory of one’s opponents.
Therefore,
there are five respects in which one may have foreknowledge of victory. He who knows when one can do battle and when one cannot do battle will be victorious. He who recognizes the functionality of the many and the few will be victorious. He who can cause superiors and inferiors to share the same desires will be victorious. He who is prepared and lies in wait for one who is unprepared will be victorious. The general who is capable and whose ruler does not interfere will be victorious. These five respects are the way to foreknowledge of victory.
Therefore,
it is said, “He who knows his opponent and knows himself will not be imperiled in a hundred battles. He who knows not his opponent but knows himself will win one and lose one. He who knows neither his opponent nor himself will surely be imperiled in every battle.”10