This chapter introduces the different types of attack by fire, the conditions necessary for using them, and the methods for carrying them out. It is of a manifestly different character from all the others in the Sun Zi, since it is the only one that deals with actual technical aspects of a specific act of war, rather than tactics and strategy. As pointed out in the introduction, this chapter shares striking parallels with Greek writings on incendiary warfare.
Master Sun said,
In all there are five different kinds of incendiary attack. They are to use fire against: 1. men,1 2. grain, 3. carts,2 4. storehouses, 5. supply lines. If one wishes to carry out an incendiary attack, all of the conditions must be right, and one must always keep a supply of incendiary materials on hand. There are suitable times and suitable days for launching incendiary attacks. The suitable times are when it is dry, and the suitable days are “Winnowing Basket,” “Wall,” “Wing,” and “Carriage Crossboard.” The times when the moon is in one of these four lunar lodges3 are the days when the wind blows strongly.
In making an incendiary attack, one must ordinarily complement it with military force. When the fire is burning inside the enemy camp, one should complement it with military force from outside as soon as possible. If the fire has already broken out but the enemy soldiers remain quiet, one should wait before attacking. When the fire has reached a peak, one may follow up with an assault if that is suitable, but if it is not suitable, refrain from an assault.
If a fire can be set from outside, you need not wait until it can be set from inside, but simply set it in a timely fashion. If the fire has been set upwind, do not attack from downwind. If a wind blows for a long time during the day, it will stop at night. An army must in all cases understand the five different varieties of incendiary attacks and stay on guard until the criteria for setting them obtain.
Therefore,
Supporting one’s attack with fire yields obvious results; supporting one’s attack with water4 yields impressive results. Water can break up enemy forces, but, unlike fire, it cannot deprive the enemy of his matériel.
To be victorious in battle and to take the enemy’s holdings through attack, but to refrain from building on your accomplishments is baleful: this may be termed a wasted opportunity.5
Therefore,
it is said, the perspicacious ruler is concerned about what to do with the spoils of war; the excellent general takes steps to build on them.
If there is no advantage, do not mobilize; if you cannot achieve your aims, do not go to war; if you are not endangered, do not engage in battle. The ruler should not, in a moment of anger, raise his armies; the general should not, in a burst of ire, embark upon battle. If it is compatible with the interests of the state, then mobilize; if it is not compatible with the interests of the state, then halt. If you are angry, you can be happy again; if you are full of ire, you can be joyful again. But if your state perishes, you cannot restore it; if your men die, you cannot bring them back to life.6
Therefore,
the perspicacious ruler is cautious; the excellent general is vigilant. This is the way of making the state secure and preserving the army intact.