. Ground which forms the key to three contiguous states,

[Ts`au Kung defines this as: "Our country adjoining the
enemy's and a third country conterminous with both." Meng Shih
instances the small principality of Cheng, which was bounded on
the north-east by Ch`i, on the west by Chin, and on the south by
Ch`u.]

so that he who occupies it first has most of the Empire at his
command,

[The belligerent who holds this dominating position can
constrain most of them to become his allies.]

is a ground of intersecting highways.
7. When an army has penetrated into the heart of a hostile
country, leaving a number of fortified cities in its rear, it is
serious ground.

[Wang Hsi explains the name by saying that "when an army has
reached such a point, its situation is serious."]

8. Mountain forests,

[Or simply "forests."]

rugged steeps, marshes and fens--all country that is hard to
traverse: this is difficult ground.
9. Ground which is reached through narrow gorges, and from
which we can only retire by tortuous paths, so that a small
number of the enemy would suffice to crush a large body of our
men: this is hemmed in ground.
10. Ground on which we can only be saved from destruction
by fighting without delay, is desperate ground.

[The situation, as pictured by Ts`ao Kung, is very similar
to the "hemmed-in ground" except that here escape is no longer
possible: "A lofty mountain in front, a large river behind,
advance impossible, retreat blocked." Ch`en Hao says: "to be on
'desperate ground' is like sitting in a leaking boat or crouching
in a burning house." Tu Mu quotes from Li Ching a vivid
description of the plight of an army thus entrapped: "Suppose an
army invading hostile territory without the aid of local guides:
-- it falls into a fatal snare and is at the enemy's mercy. A
ravine on the left, a mountain on the right, a pathway so
perilous that the horses have to be roped together and the
chariots carried in slings, no passage open in front, retreat cut
off behind, no choice but to proceed in single file. Then,
before there is time to range our soldiers in order of battle,
the enemy is overwhelming strength suddenly appears on the scene.
Advancing, we can nowhere take a breathing-space; retreating, we
have no haven of refuge. We seek a pitched battle, but in vain;
yet standing on the defensive, none of us has a moment's respite.
If we s