SUN TZU ON THE ART OF WAR

THE OLDEST MILITARY TREATISE IN THE WORLD

Translated from the Chinese By LIONEL GILES, M.A. (1910)

I. LAYING PLANS

1. Sun Tzu said: The art of war is of vital importance to the
State.

2. It is a matter of life and death, a road either to safety
or to ruin. Hence it is a subject of inquiry which can on no
account be neglected.

3. The art of war, then, is governed by five constant factors,
to be taken into account in one's deliberations, when seeking to
determine the conditions obtaining in the field.

4. These are: (1) The Moral Law; (2) Heaven; (3) Earth; (4)
The Commander; (5) Method and discipline.

5,6. The Moral Law causes the people to be in complete accord
with their ruler, so that they will follow him regardless of
their lives, undismayed by any danger.

7. Heaven signifies night and day, cold and heat, times and
seasons.

8. Earth comprises distances, great and small; danger and
security; open ground and narrow passes; the chances of life and
death.

9. The Commander stands for the virtues of wisdom, sincerely,
benevolence, courage and strictness.

10. By method and discipline are to be understood the
marshaling of the army in its proper subdivisions, the
graduations of rank among the officers, the maintenance of roads
by which supplies may reach the army, and the control of military
expenditure.

11. These five heads should be familiar to every general: he
who knows them will be victorious; he who knows them not will
fail.

12. Therefore, in your deliberations, when seeking to
determine the military conditions, let them be made the basis of
a comparison, in this wise:--

13. (1) Which of the two sovereigns is imbued with the Moral
law? (2) Which of the two generals has most ability? (3) With
whom lie the advantages derived from Heaven and Earth? (4) On
which side is discipline most rigorously enforced? (5) Which army
is stronger? (6) On which side are officers and men more highly
trained? (7) In which army is there the greater constancy both in
reward and punishment?

14. By means of these seven considerations I can forecast
victory or defeat.

15. The general that hearkens to my counsel and acts upon it,
will conquer: let such a one be retained in command! The general
that hearkens not to my counsel nor acts upon it, will suffer
defeat:--let such a one be dismissed!

16. While heading the profit of my counsel, avail yourself
also of any helpful circumstances over and beyond the ordinary
rules.

17. According as circumstances are favorable, one should
modify one's plans.

18. All warfare is based on deception.

19. Hence, when able to attack, we must seem unable; when
using our forces, we must seem inactive; when we are near, we
must make the enemy believe we are far away; when far away, we
must make him believe we are near.

20. Hold out baits to entice the enemy. Feign disorder, and
crush him.

21. If he is secure at all points, be prepared for him. If he
is in superior strength, evade him.

22. If your opponent is of choleric temper, seek to irritate
him. Pretend to be weak, that he may grow arrogant.

23. If he is taking his ease, give him no rest. If his forces
are united, separate them.

24. Attack him where he is unprepared, appear where you are
not expected.

25. These military devices, leading to victory, must not be
divulged beforehand.

26. Now the general who wins a battle makes many calculations
in his temple ere the battle is fought. The general who loses a
battle makes but few calculations beforehand. Thus do many
calculations lead to victory, and few calculations to defeat: how
much more no calculation at all! It is by attention to this point
that I can foresee who is likely to win or lose.

II. WAGING WAR

1. Sun Tzu said: In the operations of war, where there are in
the field a thousand swift chariots, as many heavy chariots, and
a hundred thousand mail-clad soldiers, with provisions enough to
carry them a thousand li, the expenditure at home and at the
front, including entertainment of guests, small items such as
glue and paint, and sums spent on chariots and armor, will reach
the total of a thousand ounces of silver per day. Such is the
cost of raising an army of 100,000 men.

2. When you engage in actual fighting, if victory is long in
coming, then men's weapons will grow dull and their ardor will be
damped. If you lay siege to a town, you will exhaust your
strength. 3. Again, if the campaign is protracted, the resources
of the State will not be equal to the strain.

4. Now, when your weapons are dulled, your ardor damped, your
strength exhausted and your treasure spent, other chieftains will
spring up to take advantage of your extremity. Then no man,
however wise, will be able to avert the consequences that must
ensue.

5. Thus, though we have heard of stupid haste in war,
cleverness has never been seen associated with long delays.

6. There is no instance of a country having benefited from
prolonged warfare.

7. It is only one who is thoroughly acquainted with the evils
of war that can thoroughly understand the profitable way of
carrying it on.

8. The skillful soldier does not raise a second levy, neither
are his supply-wagons loaded more than twice.

9. Bring war material with you from home, but forage on the
enemy. Thus the army will have food enough for its needs.

10. Poverty of the State exchequer causes an army to be
maintained by contributions from a distance. Contributing to
maintain an army at a distance causes the people to be
impoverished.

11. On the other hand, the proximity of an army causes prices
to go up; and high prices cause the people's substance to be
drained away.

12. When their substance is drained away, the peasantry will
be afflicted by heavy exactions.

13,14. With this loss of substance and exhaustion of strength,
the homes of the people will be stripped bare, and three-tenths
of their income will be dissipated; while government expenses for
broken chariots, worn-out horses, breast-plates and helmets, bows
and arrows, spears and shields, protective mantles, draught-oxen
and heavy wagons, will amount to four-tenths of its total
revenue.

15. Hence a wise general makes a point of foraging on the
enemy. One cartload of the enemy's provisions is equivalent to
twenty of one's own, and likewise a single picul of his provender
is equivalent to twenty from one's own store.

16. Now in order to kill the enemy, our men must be roused to
anger; that there may be advantage from defeating the enemy, they
must have their rewards.

17. Therefore in chariot fighting, when ten or more chariots
have been taken, those should be rewarded who took the first. Our
own flags should be substituted for those of the enemy, and the
chariots mingled and used in conjunction with ours. The captured
soldiers should be kindly treated and kept.

18. This is called, using the conquered foe to augment one's
own strength.

19. In war, then, let your great object be victory, not
lengthy campaigns.

20. Thus it may be known that the leader of armies is the
arbiter of the people's fate, the man on whom it depends whether
the nation shall be in peace or in peril.

III. ATTACK BY STRATAGEM

1. Sun Tzu said: In the practical art of war, the best thing
of all is to take the enemy's country whole and intact; to
shatter and destroy it is not so good. So, too, it is better to
recapture an army entire than to destroy it, to capture a
regiment, a detachment or a company entire than to destroy them.

2. Hence to fight and conquer in all your battles is not
supreme excellence; supreme excellence consists in breaking the
enemy's resistance without fighting.

3. Thus the highest form of generalship is to balk the enemy's
plans; the next best is to prevent the junction of the enemy's
forces; the next in order is to attack the enemy's army in the
field; and the worst policy of all is to besiege walled cities.

4. The rule is, not to besiege walled cities if it can
possibly be avoided. The preparation of mantlets, movable
shelters, and various implements of war, will take up three whole
months; and the piling up of mounds over against the walls will
take three months more.

5. The general, unable to control his irritation, will launch
his men to the assault like swarming ants, with the result that
one-third of his men are slain, while the town still remains
untaken. Such are the disastrous effects of a siege.

6. Therefore the skillful leader subdues the enemy's troops
without any fighting; he captures their cities without laying
siege to them; he overthrows their kingdom without lengthy
operations in the field.

7. With his forces intact he will dispute the mastery of the
Empire, and thus, without losing a man, his triumph will be
complete. This is the method of attacking by stratagem.

8. It is the rule in war, if our forces are ten to the enemy's
one, to surround him; if five to one, to attack him; if twice as
numerous, to divide our army into two.

9. If equally matched, we can offer battle; if slightly
inferior in numbers, we can avoid the enemy; if quite unequal in
every way, we can flee from him.

10. Hence, though an obstinate fight may be made by a small
force, in the end it must be captured by the larger force.

11. Now the general is the bulwark of the State; if the
bulwark is complete at all points; the State will be strong; if
the bulwark is defective, the State will be weak.

12. There are three ways in which a ruler can bring misfortune
upon his army:--

13. (1) By commanding the army to advance or to retreat, being
ignorant of the fact that it cannot obey. This is called hobbling
the army.

14. (2) By attempting to govern an army in the same way as he
administers a kingdom, being ignorant of the conditions which
obtain in an army. This causes restlessness in the soldier's
minds.

15. (3) By employing the officers of his army without
discrimination, through ignorance of the military principle of
adaptation to circumstances. This shakes the confidence of the
soldiers.

16. But when the army is restless and distrustful, trouble is
sure to come from the other feudal princes. This is simply
bringing anarchy into the army, and flinging victory away.

17. Thus we may know that there are five essentials for
victory: (1) He will win who knows when to fight and when not to
fight. (2) He will win who knows how to handle both superior and
inferior forces. (3) He will win whose army is animated by the
same spirit throughout all its ranks. (4) He will win who,
prepared himself, waits to take the enemy unprepared. (5) He will
win who has military capacity and is not interfered with by the
sovereign.

18. Hence the saying: If you know the enemy and know yourself,
you need not fear the result of a hundred battles. If you know
yourself but not the enemy, for every victory gained you will
also suffer a defeat. If you know neither the enemy nor yourself,
you will succumb in every battle.

IV. TACTICAL DISPOSITIONS

1. Sun Tzu said: The good fighters of old first put themselves
beyond the possibility of defeat, and then waited for an
opportunity of defeating the enemy.

2. To secure ourselves against defeat lies in our own hands,
but the opportunity of defeating the enemy is provided by the
enemy himself. 3. Thus the good fighter is able to secure himself
against defeat, but cannot make certain of defeating the enemy.

4. Hence the saying: One may know how to conquer without being
able to do it.

5. Security against defeat implies defensive tactics; ability
to defeat the enemy means taking the offensive.

6. Standing on the defensive indicates insufficient strength;
attacking, a superabundance of strength.

7. The general who is skilled in defense hides in the most
secret recesses of the earth; he who is skilled in attack flashes
forth from the topmost heights of heaven. Thus on the one hand we
have ability to protect ourselves; on the other, a victory that
is complete.

8. To see victory only when it is within the ken of the common
herd is not the acme of excellence.

9. Neither is it the acme of excellence if you fight and
conquer and the whole Empire says, "Well done!"

10. To lift an autumn hair is no sign of great strength; to
see the sun and moon is no sign of sharp sight; to hear the noise
of thunder is no sign of a quick ear.

11. What the ancients called a clever fighter is one who not
only wins, but excels in winning with ease.

12. Hence his victories bring him neither reputation for
wisdom nor credit for courage.

13. He wins his battles by making no mistakes. Making no
mistakes is what establishes the certainty of victory, for it
means conquering an enemy that is already defeated.

14. Hence the skillful fighter puts himself into a position
which makes defeat impossible, and does not miss the moment for
defeating the enemy.

15. Thus it is that in war the victorious strategist only
seeks battle after the victory has been won, whereas he who is
destined to defeat first fights and afterwards looks for victory.

16. The consummate leader cultivates the moral law, and
strictly adheres to method and discipline; thus it is in his
power to control success.

17. In respect of military method, we have, firstly,
Measurement; secondly, Estimation of quantity; thirdly,
Calculation; fourthly, Balancing of chances; fifthly, Victory.

18. Measurement owes its existence to Earth; Estimation of
quantity to Measurement; Calculation to Estimation of quantity;
Balancing of chances to Calculation; and Victory to Balancing of
chances.

19. A victorious army opposed to a routed one, is as a pound's
weight placed in the scale against a single grain.

20. The onrush of a conquering force is like the bursting of
pent-up waters into a chasm a thousand fathoms deep.

V. ENERGY

1. Sun Tzu said: The control of a large force is the same
principle as the control of a few men: it is merely a question of
dividing up their numbers.

2. Fighting with a large army under your command is nowise
different from fighting with a small one: it is merely a question
of instituting signs and signals.

3. To ensure that your whole host may withstand the brunt of
the enemy's attack and remain unshaken-- this is effected by
maneuvers direct and indirect.

4. That the impact of your army may be like a grindstone
dashed against an egg--this is effected by the science of weak
points and strong.

5. In all fighting, the direct method may be used for joining
battle, but indirect methods will be needed in order to secure
victory.

6. Indirect tactics, efficiently applied, are inexhaustible as
Heaven and Earth, unending as the flow of rivers and streams;
like the sun and moon, they end but to begin anew; like the four
seasons, they pass away to return once more.

7. There are not more than five musical notes, yet the
combinations of these five give rise to more melodies than can
ever be heard.

8. There are not more than five primary colors (blue, yellow,
red, white, and black), yet in combination they produce more hues
than can ever been seen.

9. There are not more than five cardinal tastes (sour, acrid,
salt, sweet, bitter), yet combinations of them yield more flavors
than can ever be tasted.

10. In battle, there are not more than two methods of
attack--the direct and the indirect; yet these two in combination
give rise to an endless series of maneuvers.

11. The direct and the indirect lead on to each other in turn.
It is like moving in a circle--you never come to an end. Who can
exhaust the possibilities of their combination?

12. The onset of troops is like the rush of a torrent which
will even roll stones along in its course.

13. The quality of decision is like the well-timed swoop of a
falcon which enables it to strike and destroy its victim.

14. Therefore the good fighter will be terrible in his onset,
and prompt in his decision.

15. Energy may be likened to the bending of a crossbow;
decision, to the releasing of a trigger.

16. Amid the turmoil and tumult of battle, there may be
seeming disorder and yet no real disorder at all; amid confusion
and chaos, your array may be without head or tail, yet it will be
proof against defeat.

17. Simulated disorder postulates perfect discipline,
simulated fear postulates courage; simulated weakness postulates
strength.

18. Hiding order beneath the cloak of disorder is simply a
question of subdivision; concealing courage under a show of
timidity presupposes a fund of latent energy; masking strength
with weakness is to be effected by tactical dispositions.

19. Thus one who is skillful at keeping the enemy on the move
maintains deceitful appearances, according to which the enemy
will act. He sacrifices something, that the enemy may snatch at
it.

20. By holding out baits, he keeps him on the march; then with
a body of picked men he lies in wait for him.

21. The clever combatant looks to the effect of combined
energy, and does not require too much from individuals. Hence his
ability to pick out the right men and utilize combined energy.

22. When he utilizes combined energy, his fighting men become
as it were like unto rolling logs or stones. For it is the nature
of a log or stone to remain motionless on level ground, and to
move when on a slope; if four-cornered, to come to a standstill,
but if round-shaped, to go rolling down.

23. Thus the energy developed by good fighting men is as the
momentum of a round stone rolled down a mountain thousands of
feet in height. So much on the subject of energy.

VI. WEAK POINTS AND STRONG

1. Sun Tzu said: Whoever is first in the field and awaits the
coming of the enemy, will be fresh for the fight; whoever is
second in the field and has to hasten to battle will arrive
exhausted.

2. Therefore the clever combatant imposes his will on the
enemy, but does not allow the enemy's will to be imposed on him.

3. By holding out advantages to him, he can cause the enemy to
approach of his own accord; or, by inflicting damage, he can make
it impossible for the enemy to draw near.

4. If the enemy is taking his ease, he can harass him; if well
supplied with food, he can starve him out; if quietly encamped,
he can force him to move.

5. Appear at points which the enemy must hasten to defend;
march swiftly to places where you are not expected.

6. An army may march great distances without distress, if it
marches through country where the enemy is not.

7. You can be sure of succeeding in your attacks if you only
attack places which are undefended.You can ensure the safety of
your defense if you only hold positions that cannot be attacked.

8. Hence that general is skillful in attack whose opponent
does not know what to defend; and he is skillful in defense whose
opponent does not know what to attack.

9. O divine art of subtlety and secrecy! Through you we learn
to be invisible, through you inaudible; and hence we can hold the
enemy's fate in our hands.

10. You may advance and be absolutely irresistible, if you
make for the enemy's weak points; you may retire and be safe from
pursuit if your movements are more rapid than those of the enemy.

11. If we wish to fight, the enemy can be forced to an
engagement even though he be sheltered behind a high rampart and
a deep ditch. All we need do is attack some other place that he
will be obliged to relieve.

12. If we do not wish to fight, we can prevent the enemy from
engaging us even though the lines of our encampment be merely
traced out on the ground. All we need do is to throw something
odd and unaccountable in his way.

13. By discovering the enemy's dispositions and remaining
invisible ourselves, we can keep our forces concentrated, while
the enemy's must be divided.

14. We can form a single united body, while the enemy must
split up into fractions. Hence there will be a whole pitted
against separate parts of a whole, which means that we shall be
many to the enemy's few.

15. And if we are able thus to attack an inferior force with a
superior one, our opponents will be in dire straits.

16. The spot where we intend to fight must not be made known;
for then the enemy will have to prepare against a possible attack
at several different points; and his forces being thus
distributed in many directions, the numbers we shall have to face
at any given point will be proportionately few.

17. For should the enemy strengthen his van, he will weaken
his rear; should he strengthen his rear, he will weaken his van;
should he strengthen his left, he will weaken his right; should
he strengthen his right, he will weaken his left. If he sends
reinforcements everywhere, he will everywhere be weak.

18. Numerical weakness comes from having to prepare against
possible attacks; numerical strength, from compelling our
adversary to make these preparations against us.

19. Knowing the place and the time of the coming battle, we
may concentrate from the greatest distances in order to fight.

20. But if neither time nor place be known, then the left wing
will be impotent to succor the right, the right equally impotent
to succor the left, the van unable to relieve the rear, or the
rear to support the van. How much more so if the furthest
portions of the army are anything under a hundred LI apart, and
even the nearest are separated by several LI!

21. Though according to my estimate the soldiers of Yueh
exceed our own in number, that shall advantage them nothing in
the matter of victory. I say then that victory can be achieved.

22. Though the enemy be stronger in numbers, we may prevent
him from fighting. Scheme so as to discover his plans and the
likelihood of their success.

23. Rouse him, and learn the principle of his activity or
inactivity. Force him to reveal himself, so as to find out his
vulnerable spots.

24. Carefully compare the opposing army with your own, so that
you may know where strength is superabundant and where it is
deficient.

25. In making tactical dispositions, the highest pitch you can
attain is to conceal them; conceal your dispositions, and you
will be safe from the prying of the subtlest spies, from the
machinations of the wisest brains.

26. How victory may be produced for them out of the enemy's
own tactics--that is what the multitude cannot comprehend.

27. All men can see the tactics whereby I conquer, but what
none can see is the strategy out of which victory is evolved.

28. Do not repeat the tactics which have gained you one
victory, but let your methods be regulated by the infinite
variety of circumstances.

29. Military tactics are like unto water; for water in its
natural course runs away from high places and hastens downwards.

30. So in war, the way is to avoid what is strong and to
strike at what is weak.

31. Water shapes its course according to the nature of the
ground over which it flows; the soldier works out his victory in
relation to the foe whom he is facing.

32. Therefore, just as water retains no constant shape, so in
warfare there are no constant conditions.

33. He who can modify his tactics in relation to his opponent
and thereby succeed in winning, may be called a heaven-born
captain.

34. The five elements (water, fire, wood, metal, earth) are
not always equally predominant; the four seasons make way for
each other in turn. There are short days and long; the moon has
its periods of waning and waxing.

VII. MANEUVERING

1. Sun Tzu said: In war, the general receives his commands
from the sovereign.

2. Having collected an army and concentrated his forces, he
must blend and harmonize the different elements thereof before
pitching his camp.

3. After that, comes tactical maneuvering, than which there is
nothing more difficult. The difficulty of tactical maneuvering
consists in turning the devious into the direct, and misfortune
into gain.

4. Thus, to take a long and circuitous route, after enticing
the enemy out of the way, and though starting after him, to
contrive to reach the goal before him, shows knowledge of the
artifice of DEVIATION.

5. Maneuvering with an army is advantageous; with an
undisciplined multitude, most dangerous.

6. If you set a fully equipped army in march in order to
snatch an advantage, the chances are that you will be too late.
On the other hand, to detach a flying column for the purpose
involves the sacrifice of its baggage and stores.

7. Thus, if you order your men to roll up their buff-coats,
and make forced marches without halting day or night, covering
double the usual distance at a stretch, doing a hundred LI in
order to wrest an advantage, the leaders of all your three
divisions will fall into the hands of the enemy.

8. The stronger men will be in front, the jaded ones will fall
behind, and on this plan only one-tenth of your army will reach
its destination.

9. If you march fifty LI in order to outmaneuver the enemy,
you will lose the leader of your first division, and only half
your force will reach the goal.

10. If you march thirty LI with the same object, two-thirds of
your army will arrive.

11. We may take it then that an army without its baggage-train
is lost; without provisions it is lost; without bases of supply
it is lost.

12. We cannot enter into alliances until we are acquainted
with the designs of our neighbors.

13. We are not fit to lead an army on the march unless we are
familiar with the face of the country--its mountains and forests,
its pitfalls and precipices, its marshes and swamps.

14. We shall be unable to turn natural advantage to account
unless we make use of local guides.

15. In war, practice dissimulation, and you will succeed.

16. Whether to concentrate or to divide your troops, must be
decided by circumstances.

17. Let your rapidity be that of the wind, your compactness
that of the forest.

18. In raiding and plundering be like fire, is immovability
like a mountain.

19. Let your plans be dark and impenetrable as night, and when
you move, fall like a thunderbolt.

20. When you plunder a countryside, let the spoil be divided
amongst your men; when you capture new territory, cut it up into
allotments for the benefit of the soldiery.

21. Ponder and deliberate before you make a move.

22. He will conquer who has learnt the artifice of deviation.
Such is the art of maneuvering.

23. The Book of Army Management says: On the field of battle,
the spoken word does not carry far enough: hence the institution
of gongs and drums. Nor can ordinary objects be seen clearly
enough: hence the institution of banners and flags.

24. Gongs and drums, banners and flags, are means whereby the
ears and eyes of the host may be focused on one particular point.

25. The host thus forming a single united body, is it
impossible either for the brave to advance alone, or for the
cowardly to retreat alone. This is the art of handling large
masses of men.

26. In night-fighting, then, make much use of signal-fires and
drums, and in fighting by day, of flags and banners, as a means
of influencing the ears and eyes of your army.

27. A whole army may be robbed of its spirit; a
commander-in-chief may be robbed of his presence of mind.

28. Now a soldier's spirit is keenest in the morning; by
noonday it has begun to flag; and in the evening, his mind is
bent only on returning to camp.

29. A clever general, therefore, avoids an army when its
spirit is keen, but attacks it when it is sluggish and inclined
to return. This is the art of studying moods.

30. Disciplined and calm, to await the appearance of disorder
and hubbub amongst the enemy:--this is the art of retaining
self-possession.

31. To be near the goal while the enemy is still far from it,
to wait at ease while the enemy is toiling and struggling, to be
well-fed while the enemy is famished:--this is the art of
husbanding one's strength.

32. To refrain from intercepting an enemy whose banners are in
perfect order, to refrain from attacking an army drawn up in calm
and confident array:--this is the art of studying circumstances.

33. It is a military axiom not to advance uphill against the
enemy, nor to oppose him when he comes downhill.

34. Do not pursue an enemy who simulates flight; do not attack
soldiers whose temper is keen.

35. Do not swallow bait offered by the enemy. Do not interfere
with an army that is returning home.

36. When you surround an army, leave an outlet free. Do not
press a desperate foe too hard.

37. Such is the art of warfare.

VIII. VARIATION IN TACTICS

1. Sun Tzu said: In war, the general receives his commands
from the sovereign, collects his army and concentrates his forces

2. When in difficult country, do not encamp. In country where
high roads intersect, join hands with your allies. Do not linger
in dangerously isolated positions. In hemmed-in situations, you
must resort to stratagem. In desperate position, you must fight.

3. There are roads which must not be followed, armies which
must be not attacked, towns which must be besieged, positions
which must not be contested, commands of the sovereign which must
not be obeyed.

4. The general who thoroughly understands the advantages that
accompany variation of tactics knows how to handle his troops.

5. The general who does not understand these, may be well
acquainted with the configuration of the country, yet he will not
be able to turn his knowledge to practical account.

6. So, the student of war who is unversed in the art of war of
varying his plans, even though he be acquainted with the Five
Advantages, will fail to make the best use of his men.

7. Hence in the wise leader's plans, considerations of
advantage and of disadvantage will be blended together.

8. If our expectation of advantage be tempered in this way, we
may succeed in accomplishing the essential part of our schemes.

9. If, on the other hand, in the midst of difficulties we are
always ready to seize an advantage, we may extricate ourselves
from misfortune.

10. Reduce the hostile chiefs by inflicting damage on them;
and make trouble for them, and keep them constantly engaged; hold
out specious allurements, and make them rush to any given point.

11. The art of war teaches us to rely not on the likelihood of
the enemy's not coming, but on our own readiness to receive him;
not on the chance of his not attacking, but rather on the fact
that we have made our position unassailable.

12. There are five dangerous faults which may affect a
general: (1) Recklessness, which leads to destruction; (2)
cowardice, which leads to capture; (3) a hasty temper, which can
be provoked by insults; (4) a delicacy of honor which is
sensitive to shame; (5) over-solicitude for his men, which
exposes him to worry and trouble.

13. These are the five besetting sins of a general, ruinous to
the conduct of war.

14. When an army is overthrown and its leader slain, the cause
will surely be found among these five dangerous faults. Let them
be a subject of meditation.

IX. THE ARMY ON THE MARCH

1. Sun Tzu 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 neighborhood of valleys.

2. Camp in high places, facing the sun. 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.

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.

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

6. Moor your craft higher up than the enemy, and facing the
sun. Do not move up-stream to meet the enemy. So much for river
warfare.

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

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. So
much for operations in salt-marches.

9. In dry, level country, take up an easily accessible
position with rising ground to your right and on your rear, 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
which enabled the Yellow Emperor to vanquish four several
sovereigns.

11. All armies prefer high ground to low and sunny places to
dark.

12. If you are careful of your men, and camp on hard ground,
the army will be free from disease of every kind, 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 utilize 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, confined places,
tangled thickets, quagmires and 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 neighborhood 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.

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

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

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

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

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

27. When there is much running about 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.

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. Clamor 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.

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

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; too many punishments betray a condition of dire
distress.

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

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

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.

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. What we can do is simply to concentrate all our available
strength, keep a close watch on the enemy, and obtain
reinforcements.

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

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 unless.

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

X. TERRAIN

1. Sun Tzu said: We may distinguish six kinds of terrain, to
wit: (1) Accessible ground; (2) entangling ground; (3)
temporizing ground; (4) narrow passes; (5) precipitous heights;
(6) positions at a great distance from the enemy.

2. Ground which can be freely traversed by both sides is
called accessible.

3. With regard to ground of this nature, be before the enemy
in occupying the raised and sunny spots, and carefully guard your
line of supplies. Then you will be able to fight with advantage.

4. Ground which can be abandoned but is hard to re-occupy is
called entangling.

5. From a position of this sort, if the enemy is unprepared,
you may sally forth and defeat him. But if the enemy is prepared
for your coming, and you fail to defeat him, then, return being
impossible, disaster will ensue.

6. When the position is such that neither side will gain by
making the first move, it is called temporizing ground.

7. In a position of this sort, even though the enemy should
offer us an attractive bait, it will be advisable not to stir
forth, but rather to retreat, thus enticing the enemy in his
turn; then, when part of his army has come out, we may deliver
our attack with advantage.

8. With regard to narrow passes, if you can occupy them first,
let them be strongly garrisoned and await the advent of the
enemy.

9. Should the army forestall you in occupying a pass, do not
go after him if the pass is fully garrisoned, but only if it is
weakly garrisoned.

10. With regard to precipitous heights, if you are beforehand
with your adversary, you should occupy the raised and sunny
spots, and there wait for him to come up.

11. If the enemy has occupied them before you, do not follow
him, but retreat and try to entice him away.

12. If you are situated at a great distance from the enemy,
and the strength of the two armies is equal, it is not easy to
provoke a battle, and fighting will be to your disadvantage.

13. These six are the principles connected with Earth. The
general who has attained a responsible post must be careful to
study them.

14. Now an army is exposed to six several calamities, not
arising from natural causes, but from faults for which the
general is responsible. These are: (1) Flight; (2)
insubordination; (3) collapse; (4) ruin; (5) disorganization; (6)
rout.

15. Other conditions being equal, if one force is hurled
against another ten times its size, the result will be the flight
of the former.

16. When the common soldiers are too strong and their officers
too weak, the result is insubordination. When the officers are
too strong and the common soldiers too weak, the result is
collapse.

17. When the higher officers are angry and insubordinate, and
on meeting the enemy give battle on their own account from a
feeling of resentment, before the commander-in-chief can tell
whether or no he is in a position to fight, the result is ruin.

18. When the general is weak and without authority; when his
orders are not clear and distinct; when there are no fixes duties
assigned to officers and men, and the ranks are formed in a
slovenly haphazard manner, the result is utter disorganization.

19. When a general, unable to estimate the enemy's strength,
allows an inferior force to engage a larger one, or hurls a weak
detachment against a powerful one, and neglects to place picked
soldiers in the front rank, the result must be rout.

20. These are six ways of courting defeat, which must be
carefully noted by the general who has attained a responsible
post.

21. The natural formation of the country is the soldier's best
ally; but a power of estimating the adversary, of controlling the
forces of victory, and of shrewdly calculating difficulties,
dangers and distances, constitutes the test of a great general.

22. He who knows these things, and in fighting puts his
knowledge into practice, will win his battles. He who knows them
not, nor practices them, will surely be defeated.

23. If fighting is sure to result in victory, then you must
fight, even though the ruler forbid it; if fighting will not
result in victory, then you must not fight even at the ruler's
bidding.

24. The general who advances without coveting fame and
retreats without fearing disgrace, whose only thought is to
protect his country and do good service for his sovereign, is the
jewel of the kingdom.

25. Regard your soldiers as your children, and they will
follow you into the deepest valleys; look upon them as your own
beloved sons, and they will stand by you even unto death.

26. If, however, you are indulgent, but unable to make your
authority felt; kind-hearted, but unable to enforce your
commands; and incapable, moreover, of quelling disorder: then
your soldiers must be likened to spoilt children; they are
useless for any practical purpose.

27. If we know that our own men are in a condition to attack,
but are unaware that the enemy is not open to attack, we have
gone only halfway towards victory.

28. If we know that the enemy is open to attack, but are
unaware that our own men are not in a condition to attack, we
have gone only halfway towards victory.

29. If we know that the enemy is open to attack, and also know
that our men are in a condition to attack, but are unaware that
the nature of the ground makes fighting impracticable, we have
still gone only halfway towards victory.

30. Hence the experienced soldier, once in motion, is never
bewildered; once he has broken camp, he is never at a loss.

31. Hence the saying: If you know the enemy and know yourself,
your victory will not stand in doubt; if you know Heaven and know
Earth, you may make your victory complete.

XI. THE NINE SITUATIONS

1. Sun Tzu said: The art of war recognizes nine varieties of
ground: (1) Dispersive ground; (2) facile ground; (3) contentious
ground; (4) open ground; (5) ground of intersecting highways; (6)
serious ground; (7) difficult ground; (8) hemmed-in ground; (9)
desperate ground.

2. When a chieftain is fighting in his own territory, it is
dispersive ground.

3. When he has penetrated into hostile territory, but to no
great distance, it is facile ground.

4. Ground the possession of which imports great advantage to
either side, is contentious ground.

5. Ground on which each side has liberty of movement is open
ground.

6. Ground which forms the key to three contiguous states, so
that he who occupies it first has most of the Empire at his
command, 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.

8. Mountain 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.

11. On dispersive ground, therefore, fight not. On facile
ground, halt not. On contentious ground, attack not.

12. On open ground, do not try to block the enemy's way. On
the ground of intersecting highways, join hands with your allies.

13. On serious ground, gather in plunder. In difficult ground,
keep steadily on the march.

14. On hemmed-in ground, resort to stratagem. On desperate
ground, fight.

15. Those who were called skillful leaders of old knew how to
drive a wedge between the enemy's front and rear; to prevent
co-operation between his large and small divisions; to hinder the
good troops from rescuing the bad, the officers from rallying
their men.

16. When the enemy's men were united, they managed to keep
them in disorder.

17. When it was to their advantage, they made a forward move;
when otherwise, they stopped still.

18. If asked how to cope with a great host of the enemy in
orderly array and on the point of marching to the attack, I
should say: "Begin by seizing something which your opponent
holds dear; then he will be amenable to your will."

19. Rapidity is the essence of war: take advantage of the
enemy's unreadiness, make your way by unexpected routes, and
attack unguarded spots.

20. The following are the principles to be observed by an
invading force: The further you penetrate into a country, the
greater will be the solidarity of your troops, and thus the
defenders will not prevail against you.

21. Make forays in fertile country in order to supply your
army with food.

22. Carefully study the well-being of your men, and do not
overtax them. Concentrate your energy and hoard your strength.
Keep your army continually on the move, and devise unfathomable
plans.

23. Throw your soldiers into positions whence there is no
escape, and they will prefer death to flight. If they will face
death, there is nothing they may not achieve. Officers and men
alike will put forth their uttermost strength.

24. Soldiers when in desperate straits lose the sense of fear.
If there is no place of refuge, they will stand firm. If they are
in hostile country, they will show a stubborn front. If there is
no help for it, they will fight hard.

25. Thus, without waiting to be marshaled, the soldiers will
be constantly on the qui vive; without waiting to be asked, they
will do your will; without restrictions, they will be faithful;
without giving orders, they can be trusted.

26. Prohibit the taking of omens, and do away with
superstitious doubts. Then, until death itself comes, no calamity
need be feared.

27. If our soldiers are not overburdened with money, it is not
because they have a distaste for riches; if their lives are not
unduly long, it is not because they are disinclined to longevity.

28. On the day they are ordered out to battle, your soldiers
may weep, those sitting up bedewing their garments, and those
lying down letting the tears run down their cheeks. But let them
once be brought to bay, and they will display the courage of a
Chu or a Kuei.

29. The skillful tactician may be likened to the shuai-jan.
Now the shuai-jan is a snake that is found in the ChUng
mountains. Strike at its head, and you will be attacked by its
tail; strike at its tail, and you will be attacked by its head;
strike at its middle, and you will be attacked by head and tail
both.

30. Asked if an army can be made to imitate the shuai-jan, I
should answer, Yes. For the men of Wu and the men of Yueh are
enemies; yet if they are crossing a river in the same boat and
are caught by a storm, they will come to each other's assistance
just as the left hand helps the right.

31. Hence it is not enough to put one's trust in the tethering
of horses, and the burying of chariot wheels in the ground

32. The principle on which to manage an army is to set up one
standard of courage which all must reach.

33. How to make the best of both strong and weak--that is a
question involving the proper use of ground.

34. Thus the skillful general conducts his army just as though
he were leading a single man, willy-nilly, by the hand.

35. It is the business of a general to be quiet and thus
ensure secrecy; upright and just, and thus maintain order.

36. He must be able to mystify his officers and men by false
reports and appearances, and thus keep them in total ignorance.

37. By altering his arrangements and changing his plans, he
keeps the enemy without definite knowledge. By shifting his camp
and taking circuitous routes, he prevents the enemy from
anticipating his purpose.

38. At the critical moment, the leader of an army acts like
one who has climbed up a height and then kicks away the ladder
behind him. He carries his men deep into hostile territory before
he shows his hand.

39. He burns his boats and breaks his cooking-pots; like a
shepherd driving a flock of sheep, he drives his men this way and
that, and nothing knows whither he is going.

40. To muster his host and bring it into danger:--this may be
termed the business of the general.

41. The different measures suited to the nine varieties of
ground; the expediency of aggressive or defensive tactics; and
the fundamental laws of human nature: these are things that must
most certainly be studied.

42. When invading hostile territory, the general principle is,
that penetrating deeply brings cohesion; penetrating but a short
way means dispersion.

43. When you leave your own country behind, and take your army
across neighborhood territory, you find yourself on critical
ground. When there are means of communication on all four sides,
the ground is one of intersecting highways.

44. When you penetrate deeply into a country, it is serious
ground. When you penetrate but a little way, it is facile ground.

45. When you have the enemy's strongholds on your rear, and
narrow passes in front, it is hemmed-in ground. When there is no
place of refuge at all, it is desperate ground.

46. Therefore, on dispersive ground, I would inspire my men
with unity of purpose. On facile ground, I would see that there
is close connection between all parts of my army.

47. On contentious ground, I would hurry up my rear.

48. On open ground, I would keep a vigilant eye on my
defenses. On ground of intersecting highways, I would consolidate
my alliances.

49. On serious ground, I would try to ensure a continuous
stream of supplies. On difficult ground, I would keep pushing on
along the road.

50. On hemmed-in ground, I would block any way of retreat. On
desperate ground, I would proclaim to my soldiers the
hopelessness of saving their lives.

51. For it is the soldier's disposition to offer an obstinate
resistance when surrounded, to fight hard when he cannot help
himself, and to obey promptly when he has fallen into danger.

52. We cannot enter into alliance with neighboring princes
until we are acquainted with their designs. We are not fit to
lead an army on the march unless we are familiar with the face of
the country--its mountains and forests, its pitfalls and
precipices, its marshes and swamps. We shall be unable to turn
natural advantages to account unless we make use of local guides.

53. To be ignored of any one of the following four or five
principles does not befit a warlike prince.

54. When a warlike prince attacks a powerful state, his
generalship shows itself in preventing the concentration of the
enemy's forces. He overawes his opponents, and their allies are
prevented from joining against him.

55. Hence he does not strive to ally himself with all and
sundry, nor does he foster the power of other states. He carries
out his own secret designs, keeping his antagonists in awe. Thus
he is able to capture their cities and overthrow their kingdoms.

56. Bestow rewards without regard to rule, issue orders
without regard to previous arrangements; and you will be able to
handle a whole army as though you had to do with but a single
man.

57. Confront your soldiers with the deed itself; never let
them know your design. When the outlook is bright, bring it
before their eyes; but tell them nothing when the situation is
gloomy.

58. Place your army in deadly peril, and it will survive;
plunge it into desperate straits, and it will come off in safety.

59. For it is precisely when a force has fallen into harm's
way that is capable of striking a blow for victory.

60. Success in warfare is gained by carefully accommodating
ourselves to the enemy's purpose.

61. By persistently hanging on the enemy's flank, we shall
succeed in the long run in killing the commander-in-chief.

62. This is called ability to accomplish a thing by sheer
cunning.

63. On the day that you take up your command, block the
frontier passes, destroy the official tallies, and stop the
passage of all emissaries.

64. Be stern in the council-chamber, so that you may control
the situation.

65. If the enemy leaves a door open, you must rush in.

66. Forestall your opponent by seizing what he holds dear, and
subtly contrive to time his arrival on the ground.

67. Walk in the path defined by rule, and accommodate yourself
to the enemy until you can fight a decisive battle.

68. At first, then, exhibit the coyness of a maiden, until the
enemy gives you an opening; afterwards emulate the rapidity of a
running hare, and it will be too late for the enemy to oppose
you.

XII. THE ATTACK BY FIRE

1. Sun Tzu said: There are five ways of attacking with fire.
The first is to burn soldiers in their camp; the second is to
burn stores; the third is to burn baggage trains; the fourth is
to burn arsenals and magazines; the fifth is to hurl dropping
fire amongst the enemy.

2. In order to carry out an attack, we must have means
available. The material for raising fire should always be kept in
readiness.

3. There is a proper season for making attacks with fire, and
special days for starting a conflagration.

4. The proper season is when the weather is very dry; the
special days are those when the moon is in the constellations of
the Sieve, the Wall, the Wing or the Cross-bar; for these four
are all days of rising wind.

5. In attacking with fire, one should be prepared to meet five
possible developments:

6. (1) When fire breaks out inside to enemy's camp, respond at
once with an attack from without.

7. (2) If there is an outbreak of fire, but the enemy's
soldiers remain quiet, bide your time and do not attack.

8. (3) When the force of the flames has reached its height,
follow it up with an attack, if that is practicable; if not, stay
where you are.

9. (4) If it is possible to make an assault with fire from
without, do not wait for it to break out within, but deliver your
attack at a favorable moment.

10. (5) When you start a fire, be to windward of it. Do not
attack from the leeward.

11. A wind that rises in the daytime lasts long, but a night
breeze soon falls.

12. In every army, the five developments connected with fire
must be known, the movements of the stars calculated, and a watch
kept for the proper days.

13. Hence those who use fire as an aid to the attack show
intelligence; those who use water as an aid to the attack gain an
accession of strength.

14. By means of water, an enemy may be intercepted, but not
robbed of all his belongings.

15. Unhappy is the fate of one who tries to win his battles
and succeed in his attacks without cultivating the spirit of
enterprise; for the result is waste of time and general
stagnation.

16. Hence the saying: The enlightened ruler lays his plans
well ahead; the good general cultivates his resources.

17. Move not unless you see an advantage; use not your troops
unless there is something to be gained; fight not unless the
position is critical.

18. No ruler should put troops into the field merely to
gratify his own spleen; no general should fight a battle simply
out of pique.

19. If it is to your advantage, make a forward move; if not,
stay where you are.

20. Anger may in time change to gladness; vexation may be
succeeded by content.

21. But a kingdom that has once been destroyed can never come
again into being; nor can the dead ever be brought back to life.

22. Hence the enlightened ruler is heedful, and the good
general full of caution. This is the way to keep a country at
peace and an army intact.

XIII. THE USE OF SPIES

1. Sun Tzu said: Raising a host of a hundred thousand men and
marching them great distances entails heavy loss on the people
and a drain on the resources of the State. The daily expenditure
will amount to a thousand ounces of silver. There will be
commotion at home and abroad, and men will drop down exhausted on
the highways. As many as seven hundred thousand families will be
impeded in their labor.

2. Hostile armies may face each other for years, striving for
the victory which is decided in a single day. This being so, to
remain in ignorance of the enemy's condition simply because one
grudges the outlay of a hundred ounces of silver in honors and
emoluments, is the height of inhumanity.

3. One who acts thus is no leader of men, no present help to
his sovereign, no master of victory.

4. Thus, what enables the wise sovereign and the good general
to strike and conquer, and achieve things beyond the reach of
ordinary men, is foreknowledge.

5. Now this foreknowledge cannot be elicited from spirits; it
cannot be obtained inductively from experience, nor by any
deductive calculation.

6. Knowledge of the enemy's dispositions can only be obtained
from other men.

7. Hence the use of spies, of whom there are five classes: (1)
Local spies; (2) inward spies; (3) converted spies; (4) doomed
spies; (5) surviving spies.

8. When these five kinds of spy are all at work, none can
discover the secret system. This is called "divine
manipulation of the threads." It is the sovereign's most
precious faculty.

9. Having local spies means employing the services of the
inhabitants of a district.

10. Having inward spies, making use of officials of the enemy.

11. Having converted spies, getting hold of the enemy's spies
and using them for our own purposes.

12. Having doomed spies, doing certain things openly for
purposes of deception, and allowing our spies to know of them and
report them to the enemy.

13. Surviving spies, finally, are those who bring back news
from the enemy's camp.

14. Hence it is that which none in the whole army are more
intimate relations to be maintained than with spies. None should
be more liberally rewarded. In no other business should greater
secrecy be preserved.

15. Spies cannot be usefully employed without a certain
intuitive sagacity.

16. They cannot be properly managed without benevolence and
straightforwardness.

17. Without subtle ingenuity of mind, one cannot make certain
of the truth of their reports.

18. Be subtle! be subtle! and use your spies for every kind of
business.

19. If a secret piece of news is divulged by a spy before the
time is ripe, he must be put to death together with the man to
whom the secret was told.

20. Whether the object be to crush an army, to storm a city,
or to assassinate an individual, it is always necessary to begin
by finding out the names of the attendants, the aides-de-camp,
and door-keepers and sentries of the general in command. Our
spies must be commissioned to ascertain these.

21. The enemy's spies who have come to spy on us must be
sought out, tempted with bribes, led away and comfortably housed.
Thus they will become converted spies and available for our
service.

22. It is through the information brought by the converted spy
that we are able to acquire and employ local and inward spies.

23. It is owing to his information, again, that we can cause
the doomed spy to carry false tidings to the enemy.

24. Lastly, it is by his information that the surviving spy
can be used on appointed occasions.

25. The end and aim of spying in all its five varieties is
knowledge of the enemy; and this knowledge can only be derived,
in the first instance, from the converted spy. Hence it is
essential that the converted spy be treated with the utmost
liberality.

26. Of old, the rise of the Yin dynasty was due to I Chih who
had served under the Hsia. Likewise, the rise of the Chou dynasty
was due to Lu Ya who had served under the Yin.

27. Hence it is only the enlightened ruler and the wise general who will use
the highest intelligence of the army for purposes of spying and thereby they
achieve great results. Spies are a most important element in water, because
on them depends an army's ability to move.