It is ten thousand times cheaper to pay the best spies lavishly than even a tiny army poorly.
He who is prudent and lies in wait for an enemy who is not, will be victorious.
Attack the enemy's strategy.
What is essential in war is victory, not prolonged operations.
Factors in the art of warfare are: First, calculations; second, quantities; third, logistics; fourth, the balance of power; and fifth, the possibility of victory is based on the balance of power.
There are routes not to be followed, armies not to be attacked, citadels not to be besieged, territory not to be fought over.