all his belongings.
[Ts’ao Kung’s note is: "We can merely obstruct the enemy’s road or
divide his army, but not sweep away all his accumulated stores." Water
can do useful service, but it lacks the terrible destructive power of
fire. This is the reason, Chang Yu concludes, why the former is
dismissed in a couple of sentences, whereas the attack by fire is
discussed in detail. Wu Tzŭ (ch. 4) speaks thus of the two elements:
"If an army is encamped on low-lying marshy ground, from which the
water cannot run off, and where the rainfall is heavy, it may be
submerged by a flood. If an army is encamped in wild marsh lands
thickly overgrown with weeds and brambles, and visited by frequent
gales, it may be exterminated by fire."]