Chapter IX — THE ARMY ON THE MARCH

[The contents of this interesting chapter are better indicated in § 1 than by
this heading.]

1. Sun Tzŭ said: We come now to the question of encamping the army, and
observing signs of the enemy. Pass quickly over mountains, and keep in the
neighbourhood of valleys.

[The idea is, not to linger among barren uplands, but to keep close to supplies
of water and grass. Cf. Wu Tzŭ, ch. 3: “Abide not in natural ovens,” i.e. “the
openings of valleys.” Chang Yu tells the following anecdote: Wu-tu
Ch’iang was a robber captain in the time of the Later Han, and Ma Yuan
was sent to exterminate his gang. Ch’iang having found a refuge in the
hills, Ma Yuan made no attempt to force a battle, but seized all the favourable
positions commanding supplies of water and forage. Ch’iang was soon in
such a desperate plight for want of provisions that he was forced to make a
total surrender. He did not know the advantage of keeping in the neighbourhood
of valleys.”]

2. Camp in high places,

[Not on high hills, but on knolls or hillocks elevated above the surrounding
country.]

facing the sun.

[Tu Mu takes this to mean “facing south,” and Ch’en Hao “facing east.”
Cf. infra, §§ 11, 13.

Do not climb heights in order to fight. So much for mountain warfare.

3. After crossing a river, you should get far away from it.

[“In order to tempt the enemy to cross after you,” according to Ts’ao
Kung, and also, says Chang Yu, “in order not to be impeded in your evolutions.”
The T’ung Tien reads, “If the enemy crosses a river,” etc. But in view of
the next sentence, this is almost certainly an interpolation.]

4. When an invading force crosses a river in its onward march, do not advance
to meet it in mid-stream. It will be best to let half the army get across, and
then deliver your attack.

[Li Ch’uan alludes to the great victory won by Han Hsin over Lung Chu at
the Wei River. Turning to the Ch’ien Han Shu, ch. 34, fol. 6 verso, we
find the battle described as follows: “The two armies were drawn up on opposite
sides of the river. In the night, Han Hsin ordered his men to take some ten
thousand sacks filled with sand and construct a dam higher up. Then, leading
half his army across, he attacked Lung Chu; but after a time, pretending to
have failed in his attempt, he hastily withdrew to the other bank. Lung Chu was
much elated by this unlooked-for success, and exclaiming: “I felt sure that Han
Hsin was really a coward!” he pursued him and began crossing the river in his
turn. Han Hsin now sent a party to cut open the sandbags, thus releasing a
great volume of water, which swept down and prevented the greater portion of
Lung Chu’s army from getting across. He then turned upon the force which had
been cut off, and annihilated it, Lung Chu himself being amongst the slain. The
rest of the army, on the further bank, also scattered and fled in all
directions.]

5. If you are anxious to fight, you should not go to meet the invader near a
river which he has to cross.

[For fear of preventing his crossing.]

6. Moor your craft higher up than the enemy, and facing the sun.

[See supra, § 2. The repetition of these words in connection with water is very
awkward. Chang Yu has the note: “Said either of troops marshalled on the
river-bank, or of boats anchored in the stream itself; in either case it is
essential to be higher than the enemy and facing the sun.” The other
commentators are not at all explicit.]

Do not move up-stream to meet the enemy.

[Tu Mu says: “As water flows downwards, we must not pitch our camp on the lower
reaches of a river, for fear the enemy should open the sluices and sweep us
away in a flood. Chu-ko Wu-hou has remarked that ‘in river warfare we must not
advance against the stream,’ which is as much as to say that our fleet must not
be anchored below that of the enemy, for then they would be able to take
advantage of the current and make short work of us.” There is also the danger,
noted by other commentators, that the enemy may throw poison on the water to be
carried down to us.]

So much for river warfare.

7. In crossing salt-marshes, your sole concern should be to get over them
quickly, without any delay.

[Because of the lack of fresh water, the poor quality of the herbage, and last
but not least, because they are low, flat, and exposed to attack.]

8. If forced to fight in a salt-marsh, you should have water and grass near
you, and get your back to a clump of trees.

[Li Ch’uan remarks that the ground is less likely to be treacherous where
there are trees, while Tu Mu says that they will serve to protect the rear.]

So much for operations in salt-marshes.

9. In dry, level country, take up an easily accessible position with rising
ground to your right and on your rear,

[Tu Mu quotes T’ai Kung as saying: “An army should have a stream or a
marsh on its left, and a hill or tumulus on its right.”]

so that the danger may be in front, and safety lie behind. So much for
campaigning in flat country.

10. These are the four useful branches of military knowledge

[Those, namely, concerned with (1) mountains, (2) rivers, (3) marshes, and (4)
plains. Compare Napoleon’s “Military Maxims,” no. 1.]

which enabled the Yellow Emperor to vanquish four several sovereigns.

[Regarding the “Yellow Emperor”: Mei Yao-ch’en asks, with some
plausibility, whether there is an error in the text as nothing is known of
Huang Ti having conquered four other Emperors. The Shih Chi (ch. 1 ad init.)
speaks only of his victories over Yen Ti and Ch’ih Yu. In the Liu
T’ao it is mentioned that he “fought seventy battles and pacified the
Empire.” Ts’ao Kung’s explanation is, that the Yellow Emperor was the
first to institute the feudal system of vassals princes, each of whom (to the
number of four) originally bore the title of Emperor. Li Ch’uan tells us
that the art of war originated under Huang Ti, who received it from his
Minister Feng Hou.]

11. All armies prefer high ground to low,

[“High Ground,” says Mei Yao-ch’en, “is not only more agreeable and
salubrious, but more convenient from a military point of view; low ground is
not only damp and unhealthy, but also disadvantageous for fighting.”]

and sunny places to dark.

12. If you are careful of your men,

[Ts’ao Kung says: “Make for fresh water and pasture, where you can turn
out your animals to graze.”]

and camp on hard ground, the army will be free from disease of every kind,

[Chang Yu says: “The dryness of the climate will prevent the outbreak of
illness.”]

and this will spell victory.

13. When you come to a hill or a bank, occupy the sunny side, with the slope on
your right rear. Thus you will at once act for the benefit of your soldiers and
utilise the natural advantages of the ground.

14. When, in consequence of heavy rains up-country, a river which you wish to
ford is swollen and flecked with foam, you must wait until it subsides.

15. Country in which there are precipitous cliffs with torrents running
between, deep natural hollows,

The latter defined as “places enclosed on every side by steep banks, with pools
of water at the bottom.”]

confined places,

[Defined as “natural pens or prisons” or “places surrounded by precipices on
three sides—easy to get into, but hard to get out of.”]

tangled thickets,

[Defined as “places covered with such dense undergrowth that spears cannot be
used.”]

quagmires

[Defined as “low-lying places, so heavy with mud as to be impassable for
chariots and horsemen.”]

and crevasses,

[Defined by Mei Yao-ch’en as “a narrow difficult way between beetling
cliffs.” Tu Mu’s note is “ground covered with trees and rocks, and intersected
by numerous ravines and pitfalls.” This is very vague, but Chia Lin explains it
clearly enough as a defile or narrow pass, and Chang Yu takes much the same
view. On the whole, the weight of the commentators certainly inclines to the
rendering “defile.” But the ordinary meaning of the Chinese in one place is “a
crack or fissure” and the fact that the meaning of the Chinese elsewhere in the
sentence indicates something in the nature of a defile, make me think that Sun
Tzŭ is here speaking of crevasses.]

should be left with all possible speed and not approached.

16. While we keep away from such places, we should get the enemy to approach
them; while we face them, we should let the enemy have them on his rear.

17. If in the neighbourhood of your camp there should be any hilly country,
ponds surrounded by aquatic grass, hollow basins filled with reeds, or woods
with thick undergrowth, they must be carefully routed out and searched; for
these are places where men in ambush or insidious spies are likely to be
lurking.

[Chang Yu has the note: “We must also be on our guard against traitors who may
lie in close covert, secretly spying out our weaknesses and overhearing our
instructions.”]

18. When the enemy is close at hand and remains quiet, he is relying on the
natural strength of his position.

[Here begin Sun Tzŭ’s remarks on the reading of signs, much of which is so good
that it could almost be included in a modern manual like Gen. Baden-Powell’s
“Aids to Scouting.”]

19. When he keeps aloof and tries to provoke a battle, he is anxious for the
other side to advance.

[Probably because we are in a strong position from which he wishes to dislodge
us. “If he came close up to us, says Tu Mu, “and tried to force a battle, he
would seem to despise us, and there would be less probability of our responding
to the challenge.”]

20. If his place of encampment is easy of access, he is tendering a bait.

21. Movement amongst the trees of a forest shows that the enemy is advancing.

[Ts’ao Kung explains this as “felling trees to clear a passage,” and
Chang Yu says: “Every man sends out scouts to climb high places and observe the
enemy. If a scout sees that the trees of a forest are moving and shaking, he
may know that they are being cut down to clear a passage for the enemy’s
march.”]

The appearance of a number of screens in the midst of thick grass means that
the enemy wants to make us suspicious.

[Tu Yu’s explanation, borrowed from Ts’ao Kung’s, is as follows: “The
presence of a number of screens or sheds in the midst of thick vegetation is a
sure sign that the enemy has fled and, fearing pursuit, has constructed these
hiding-places in order to make us suspect an ambush.” It appears that these
“screens” were hastily knotted together out of any long grass which the
retreating enemy happened to come across.]

22. The rising of birds in their flight is the sign of an ambuscade.

[Chang Yu’s explanation is doubtless right: “When birds that are flying along
in a straight line suddenly shoot upwards, it means that soldiers are in ambush
at the spot beneath.”]

Startled beasts indicate that a sudden attack is coming.

23. When there is dust rising in a high column, it is the sign of chariots
advancing; when the dust is low, but spread over a wide area, it betokens the
approach of infantry.

[“High and sharp,” or rising to a peak, is of course somewhat exaggerated as
applied to dust. The commentators explain the phenomenon by saying that horses
and chariots, being heavier than men, raise more dust, and also follow one
another in the same wheel-track, whereas foot-soldiers would be marching in
ranks, many abreast. According to Chang Yu, “every army on the march must have
scouts some way in advance, who on sighting dust raised by the enemy, will
gallop back and report it to the commander-in-chief.” Cf. Gen. Baden-Powell:
“As you move along, say, in a hostile country, your eyes should be looking afar
for the enemy or any signs of him: figures, dust rising, birds getting up,
glitter of arms, etc.” [1] ]

When it branches out in different directions, it shows that parties have been
sent to collect firewood. A few clouds of dust moving to and fro signify that
the army is encamping.

[Chang Yu says: “In apportioning the defences for a cantonment, light horse
will be sent out to survey the position and ascertain the weak and strong
points all along its circumference. Hence the small quantity of dust and its
motion.”]

24. Humble words and increased preparations are signs that the enemy is about
to advance.

[“As though they stood in great fear of us,” says Tu Mu. “Their object is to
make us contemptuous and careless, after which they will attack us.” Chang Yu
alludes to the story of T’ien Tan of the Ch’i-mo against the Yen
forces, led by Ch’i Chieh. In ch. 82 of the Shih Chi we read:
“T’ien Tan openly said: ‘My only fear is that the Yen army may cut off
the noses of their Ch’i prisoners and place them in the front rank to
fight against us; that would be the undoing of our city.’ The other side being
informed of this speech, at once acted on the suggestion; but those within the
city were enraged at seeing their fellow-countrymen thus mutilated, and fearing
only lest they should fall into the enemy’s hands, were nerved to defend
themselves more obstinately than ever. Once again T’ien Tan sent back
converted spies who reported these words to the enemy: “What I dread most is
that the men of Yen may dig up the ancestral tombs outside the town, and by
inflicting this indignity on our forefathers cause us to become faint-hearted.’
Forthwith the besiegers dug up all the graves and burned the corpses lying in
them. And the inhabitants of Chi-mo, witnessing the outrage from the
city-walls, wept passionately and were all impatient to go out and fight, their
fury being increased tenfold. T’ien Tan knew then that his soldiers were
ready for any enterprise. But instead of a sword, he himself took a mattock in
his hands, and ordered others to be distributed amongst his best warriors,
while the ranks were filled up with their wives and concubines. He then served
out all the remaining rations and bade his men eat their fill. The regular
soldiers were told to keep out of sight, and the walls were manned with the old
and weaker men and with women. This done, envoys were dispatched to the enemy’s
camp to arrange terms of surrender, whereupon the Yen army began shouting for
joy. T’ien Tan also collected 20,000 ounces of silver from the people,
and got the wealthy citizens of Chi-mo to send it to the Yen general with the
prayer that, when the town capitulated, he would not allow their homes to be
plundered or their women to be maltreated. Ch’i Chieh, in high good
humor, granted their prayer; but his army now became increasingly slack and
careless. Meanwhile, T’ien Tan got together a thousand oxen, decked them
with pieces of red silk, painted their bodies, dragon-like, with colored
stripes, and fastened sharp blades on their horns and well-greased rushes on
their tails. When night came on, he lighted the ends of the rushes, and drove
the oxen through a number of holes which he had pierced in the walls, backing
them up with a force of 5000 picked warriors. The animals, maddened with pain,
dashed furiously into the enemy’s camp where they caused the utmost confusion
and dismay; for their tails acted as torches, showing up the hideous pattern on
their bodies, and the weapons on their horns killed or wounded any with whom
they came into contact. In the meantime, the band of 5000 had crept up with
gags in their mouths, and now threw themselves on the enemy. At the same moment
a frightful din arose in the city itself, all those that remained behind making
as much noise as possible by banging drums and hammering on bronze vessels,
until heaven and earth were convulsed by the uproar. Terror-stricken, the Yen
army fled in disorder, hotly pursued by the men of Ch’i, who succeeded in
slaying their general Ch’i Chien…. The result of the battle was the
ultimate recovery of some seventy cities which had belonged to the Ch’i
State.”]

Violent language and driving forward as if to the attack are signs that he will
retreat.

25. When the light chariots come out first and take up a position on the wings,
it is a sign that the enemy is forming for battle.

26. Peace proposals unaccompanied by a sworn covenant indicate a plot.

[The reading here is uncertain. Li Ch’uan indicates “a treaty confirmed
by oaths and hostages.” Wang Hsi and Chang Yu, on the other hand, simply say
“without reason,” “on a frivolous pretext.”]

27. When there is much running about

[Every man hastening to his proper place under his own regimental banner.]

and the soldiers fall into rank, it means that the critical moment has come.

28. When some are seen advancing and some retreating, it is a lure.

29. When the soldiers stand leaning on their spears, they are faint from want
of food.

30. If those who are sent to draw water begin by drinking themselves, the army
is suffering from thirst.

[As Tu Mu remarks: “One may know the condition of a whole army from the
behavior of a single man.”]

31. If the enemy sees an advantage to be gained and makes no effort to secure
it, the soldiers are exhausted.

32. If birds gather on any spot, it is unoccupied.

[A useful fact to bear in mind when, for instance, as Ch’en Hao says, the
enemy has secretly abandoned his camp.]

Clamour by night betokens nervousness.

33. If there is disturbance in the camp, the general’s authority is weak. If
the banners and flags are shifted about, sedition is afoot. If the officers are
angry, it means that the men are weary.

[Tu Mu understands the sentence differently: “If all the officers of an army
are angry with their general, it means that they are broken with fatigue” owing
to the exertions which he has demanded from them.]

34. When an army feeds its horses with grain and kills its cattle for food,

[In the ordinary course of things, the men would be fed on grain and the horses
chiefly on grass.]

and when the men do not hang their cooking-pots over the camp-fires, showing
that they will not return to their tents, you may know that they are determined
to fight to the death.

[I may quote here the illustrative passage from the Hou Han Shu, ch. 71, given
in abbreviated form by the P’ei Wen Yun Fu: “The rebel Wang Kuo of Liang
was besieging the town of Ch’en- ts’ang, and Huang-fu Sung, who was
in supreme command, and Tung Cho were sent out against him. The latter pressed
for hasty measures, but Sung turned a deaf ear to his counsel. At last the
rebels were utterly worn out, and began to throw down their weapons of their
own accord. Sung was not advancing to the attack, but Cho said: ‘It is a
principle of war not to pursue desperate men and not to press a retreating
host.’ Sung answered: ‘That does not apply here. What I am about to attack is a
jaded army, not a retreating host; with disciplined troops I am falling on a
disorganized multitude, not a band of desperate men.’ Thereupon he advances to
the attack unsupported by his colleague, and routed the enemy, Wang Kuo being
slain.”]

35. The sight of men whispering together in small knots or speaking in subdued
tones points to disaffection amongst the rank and file.

36. Too frequent rewards signify that the enemy is at the end of his resources;

[Because, when an army is hard pressed, as Tu Mu says, there is always a fear
of mutiny, and lavish rewards are given to keep the men in good temper.]

too many punishments betray a condition of dire distress.

[Because in such case discipline becomes relaxed, and unwonted severity is
necessary to keep the men to their duty.]

37. To begin by bluster, but afterwards to take fright at the enemy’s numbers,
shows a supreme lack of intelligence.

[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 Tzŭ 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 manœuver 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 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.”]

41. He who exercises no forethought but makes light of his opponents is sure to
be captured by them.

[Ch’en Hao, quoting from the Tso Chuan, says: “If bees and scorpions
carry poison, how much more will a hostile state! Even a puny opponent, then,
should not be treated with contempt.”]

42. If soldiers are punished before they have grown attached to you, they will
not prove submissive; and, unless submissive, then will be practically useless.
If, when the soldiers have become attached to you, punishments are not
enforced, they will still be useless.

43. Therefore soldiers must be treated in the first instance with humanity, but
kept under control by means of iron discipline.

[Yen Tzŭ [B.C. 493] said of Ssu-ma Jang-chu: “His civil virtues endeared him to
the people; his martial prowess kept his enemies in awe.” Cf. Wu Tzŭ, ch. 4
init.: “The ideal commander unites culture with a warlike temper; the
profession of arms requires a combination of hardness and tenderness.”]

This is a certain road to victory.

44. If in training soldiers commands are habitually enforced, the army will be
well-disciplined; if not, its discipline will be bad.

45. If a general shows confidence in his men but always insists on his orders
being obeyed,

[Tu Mu says: “A general ought in time of peace to show kindly confidence in his
men and also make his authority respected, so that when they come to face the
enemy, orders may be executed and discipline maintained, because they all trust
and look up to him.” What Sun Tzŭ has said in § 44, however, would lead one
rather to expect something like this: “If a general is always confident that
his orders will be carried out,” etc.”]

the gain will be mutual.

[Chang Yu says: “The general has confidence in the men under his command, and
the men are docile, having confidence in him. Thus the gain is mutual.” He
quotes a pregnant sentence from Wei Liao Tzŭ, ch. 4: “The art of giving orders
is not to try to rectify minor blunders and not to be swayed by petty doubts.”
Vacillation and fussiness are the surest means of sapping the confidence of an
army.]

[1] “Aids to Scouting,” p. 26.