Those who excel in war first cultivate their own humanity and and maintain their laws and institutions. By these means they make their governments invincible.
The art of using troops is this:
......When ten to the enemy's one, surround him;
......When five times his strength, attack him;
......If double his strength, divide him;
......If equally matched you may engage him;
......If weaker numerically, be capable of withdrawing;
......And if in all respects unequal, be capable of eluding him,
..........for a small force is but booty for one more powerful.
The sovereign must have full knowledge of the activities of the five sorts of agents. This knowledge must come from the double agents, and therefore it is mandatory that they be treated with the utmost liberality.
When the enemy's envoy's speak in humble terms, but continues his preparations, he will advance. When their language is deceptive but the enemy pretentiously advances, he will retreat. When the envoys speak in apologetic terms, he wishes a respite. When without a previous understanding the enemy asks for a truce, he is plotting. When the enemy sees an advantage but does not advance to seize it, he is fatigued.
When one treats people with benevolence, justice and righteousness, and reposes confidence in them, the army will be united in mind and all will be happy to serve their leaders.
The general who wins a battle makes many calculations in his temple ere the battle is fought. The general who loses a battle makes but few calculations beforehand. Thus do many calculations lead to victory, and few calculations to defeat: how much more no calculation at all! It is by attention to this point that I can foresee who is likely to win or lose.
Whoever is first in the field and awaits the coming of the enemy, will be fresh for the fight; whoever is second in the field and has to hasten to battle will arrive exhausted.
If, however, you are indulgent, but unable to make your authority felt; kind-hearted, but unable to enforce your commands; and incapable, moreover, of quelling disorder: then your soldiers must be likened to spoilt children; they are useless for any practical purpose.
The general must be the first in the toils and fatigues of the army. In the heat of summer he does not spread his parasol nor in the cold of winter don thick clothing. In dangerous places he must dismount and walk. He waits until the army's wells have been dug and only then drinks; until the army's food is cooked before he eats; until the army's fortifications have been completed, to shelter himself.