SUN ZI said:  There are five ways of attacking with fire. The first is to burn soldiers in their camp; the second, to burn provision and stores; the third, to burn baggage-trains; the fourth, to burn arsenals and magazines; and the fifth, to burn the lines of transportation. To use fire, some medium must be relied upon.  Materials for setting fire must always be at hand.  There are suitable  seasons to attack with fire, and special days for starting a conflagration,  the suitable seasons are when the weather is very dry; the special days are those when the moon is in the constellations of the Sieve, the Wall, the Wing or the Cross-bar; for when the moon is in these positions there are likely to be strong winds all day long.

    Now, in attacking with fire, one must respond to the five changing situations:  When fire breaks out in the enemy's camp, immediately coordinate your action from without.  If there is an outbreak of fire, but the enemy's soldiers remain clam, bide your time and do not attack.  When the force of the flames has reached its height, follow it up with an attack, if that is practicable; if not, stay where you are.  If fires can be raised from outside the enemy's camps, it is not necessary to wait until they are started inside.  Attack with fire only when the moment is suitable.  If the fire starts from up-wind, do not launch arrack from down-wind. When the wind continues blowing during the day, then it is likely to die down at night.  Now, the army must know ;he five different fire-attack situations and wait for appropriate times,

    Those who use fire to assist their attacks can achieve tangible results; those who use inundations can make their attacks  more powerful.  Water can intercept and isolate an enemy, but cannot deprive him of the supplies or equipments.

    Now, to win battles and capture lands and cities, but to fail to consolidate these  achievements is ominous and may be described as a waste of resources and time. And, therefore, the enlightened rulers must deliberate upon the plans to go to battle,  and good generals carefully execute them. If not in the interests of the state, do not act.  If you are not sure of success,  do not use troops. If you are not in danger, do not fight a battle.  A sovereign should not launch a war simply out of anger, nor should a general fight a war simply out of resentment.  Take action if it is to your advantage; cancel the action if it is not.  An angered man can become happy again, just as a resentful one can feel pleased again,  but a state that has perished can never revive, nor can a dead man be brought back to life.  Therefore, with regard to the matter of war, the enlightened ruler is prudent, and the good general is full of caution. Thus, the state is kept secure and the army preserved.