To be near the goal while the enemy is still far from it, to wait at ease while the enemy is toiling and struggling, to be well-fed while the enemy is famished:—this is the art of husbanding one’s strength.
To refrain from intercepting an enemy whose banners are in perfect order, to refrain from attacking an army drawn up in calm and confident array: —this is the art of studying circumstances.
It is a military axiom not to advance uphill against the enemy, nor to oppose him when he comes downhill.
Do not pursue an enemy who simulates flight; do not attack soldiers whose temper is keen.
Do not swallow bait offered by the enemy. Do not interfere with an army that is returning home.
When you surround an army, leave an outlet free. Do not press a desperate foe too hard.
Such is the art of warfare.