[I follow the interpretation of Ts`ao Kung, also adopted by
Li Ch`uan, Tu Mu, and Chang Yu. Another possible meaning set
forth by Tu Yu, Chia Lin, Mei Tao-ch`en and Wang Hsi, is: "The
general who is first tyrannical towards his men, and then in
terror lest they should mutiny, etc." This would connect the
sentence with what went before about rewards and punishments.]

38. When envoys are sent with compliments in their mouths,
it is a sign that the enemy wishes for a truce.

[Tu Mu says: "If the enemy open friendly relations be
sending hostages, it is a sign that they are anxious for an
armistice, either because their strength is exhausted or for some
other reason." But it hardly needs a Sun Tzu to draw such an
obvious inference.]

39. If the enemy's troops march up angrily and remain
facing ours for a long time without either joining battle or
taking themselves off again, the situation is one that demands
great vigilance and circumspection.

[Ts`ao Kung says a maneuver of this sort may be only a ruse
to gain time for an unexpected flank attack or the laying of an
ambush.]

40. If our troops are no more in number than the enemy,
that is amply 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 favorable 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 Tzu, ch. 3: "The nominal
strength of mercenary troops may be 100,000, but their real value
will be not more than half that figure."]

41. He who exercises