sufficient; it only means that no direct attack can be made.
[Literally, "no martial advance." That is to say, _cheng_ tactics and
frontal attacks must be eschewed, and stratagem resorted to instead.]
What we can do is simply to concentrate all our available strength,
keep a close watch on the enemy, and obtain reinforcements.
[This is an obscure sentence, and none of the commentators succeed in
squeezing very good sense out of it. I follow Li Ch’uan, who appears to
offer the simplest explanation: "Only the side that gets more men will
win." Fortunately we have Chang Yu to expound its meaning to us in
language which is lucidity itself: "When the numbers are even, and no
favourable opening presents itself, although we may not be strong enough
to deliver a sustained attack, we can find additional recruits amongst
our sutlers and camp-followers, and then, concentrating our forces and
keeping a close watch on the enemy, contrive to snatch the victory. But
we must avoid borrowing foreign soldiers to help us." He then quotes
from Wei Liao Tzŭ, ch. 3: "The nominal strength of mercenary troops may
be 100,000, but their real value will be not more than half that
figure."]