Thus the highest form of generalship is to balk the enemy’s plans; the
next best is to prevent the junction of the enemy’s forces; the next in
order is to attack the enemy’s army in the field; and the worst policy of all
is to besiege walled cities. .....
The general, unable to control his irritation, will launch his men to the
assault like swarming ants, with the result that one-third of his men are
slain, while the town still remains untaken. Such are the disastrous effects
of a siege. ......
Hence the saying: If you know the enemy and know yourself, you need
not fear the result of a hundred battles. If you know yourself but not the
enemy, for every victory gained you will also suffer a defeat. If you know
neither the enemy nor yourself, you will succumb in every battle.