He who knows his enemy and himself well will not be defeated easily.

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.

If this is long delayed, weapons are blunted and morale depressed.

The dance of battle is always played to the same impatient rhythm. What begins in a surge of violent motion is always reduced to the perfectly still.

When you do battle, even if you are winning, if you continue for a long time it will dull your forces and blunt you edge...If you keep your armies out in the field for a long time, your supplies will be insufficient. Transportation of provisions itself consumes 20 times the amount transported.

One need not destroy one's enemy. One need only destroy his willingness to engage.

Of all rewards none [is] more liberal than those given to secret agents.