III: Planning A Siege
The general rule for use of the military is that it is better to keep a
nation intact than to destroy it. It is better to keep an army intact than
to destroy it, better to keep a division intact than to destroy it, better
to keep a battalion intact than to destroy it, better to keep a unit intact
than to destroy it.
Therefore those who win every battle are not really skillful -- those who render others' armies helpless without fighting are the best of all.
The superior militarist strikes while schemes are being laid. The next best is to attack alliances. The next best is to attack the army.
The lowest is to attack a city. Siege of a city is only done as a last resort.
Take three months to prepare your machines and three months to complete your siege engineering.
If the general cannot overcome his anger and has his army swarm over the citadel, killing a third of his soldiers, and yet the citadel is still not taken, this is a disastrous attack.
Therefore one who is good at martial arts overcomes others' forces without battle, conquers others' cities without siege, destroys others' nations without taking a long time.
It is imperative to contest all factions for complete victory, so the army is not garrisoned and the profit can be total. This is the law of strategic siege.
So the rule for use of the military is that if you outnumber the opponent ten to one, then surround them; five to one, attack; two to one, divide.
If you are equal, then fight if you are able. If youare fewer, then keep away if you are able. If you are not as good, then flee if you are able.
Therefore if the smaller side is stubborn, it becomes the captive of the larger side.
Generals are assistants of the nation. When their assistance is complete, the country is strong. When their assistance is defective, the country is weak.
So there are three ways in which a civil leadership causes the military trouble. When a civil leadership unaware of the facts tells its armies to advance when it should not, or tells its armies to retreat when it should not, this is called tying up the armies. When the civil leadership is ignorant of military affairs but shares equally in the government of the armies, the soldiers get confused. When the civil leadership is ignorant of military maneuvers but shares equally in the command of the armies, the soldiers hesitate. Once the armies are confused and hesitant, trouble comes from competitors. This is called taking away victory by deranging the military.
So there are five ways of knowing who will win. Those who know when to fight and when not to fight are victorious. Those who discern when to use many or few troops are victorious. Those whose upper and lower ranks have the same desire are victorious. Those whose generals are able and are not constrained by their governments are victorious. These five are the ways to know who will win.
So it is said that if you know others and know yourself, you will not be imperiled in a hundred battles; if you do not know others but know yourself, you win one and lose one; if you do not know others and do not know yourself, you will be imperiled in every single battle.