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.
Written over 2,400 years ago by a Chinese general named Sun Tzu, The Art of War is the oldest military treatise in the world. But despite its age and focus on ancient warfare with chariots and spears, its principles about strategy, leadership, and understanding human nature are still used today by business executives, sports coaches, politicians, and anyone who needs to outthink an opponent.
The core message is simple but profound:Â The greatest victory is one that requires no fighting.
Sun Tzu opens by declaring that war is a matter of life and death, too important to be neglected. Before any campaign, a general must evaluate five constant factors:
The Moral Law means the people are in complete accord with their ruler, willing to follow him regardless of danger. Heaven covers night and day, cold and heat, seasons and timing. Earth includes distances, danger and security, open ground and narrow passes. The Commander must possess wisdom, sincerity, benevolence, courage, and strictness. Method and Discipline refers to organization, supply lines, and control of military spending.
Using these five factors, a general makes seven comparisons: Which sovereign has the moral law? Which general has more ability? Who has advantages from heaven and earth? On which side is discipline more enforced? Which army is stronger? Which has better trained officers and men? On which side is there greater consistency in reward and punishment?
The most famous principle from this chapter:Â “All warfare is based on deception.” When able to attack, seem unable. When using your forces, seem inactive. When near, make the enemy believe you are far away. Hold out baits to entice him. Attack where he is unprepared, appear where you are not expected.
The general who makes many calculations before battle wins; the one who makes few calculations loses.
Sun Tzu warns that prolonged warfare is disastrous. Raising an army of 100,000 men costs a fortune daily. If victory takes too long, weapons grow dull, ardor dampens, and the state’s resources are drained. Worse, other chieftains will spring up to take advantage of your weakness.
The key lesson: There is no instance of a country benefiting from prolonged warfare. The skillful soldier does not raise a second levy or load supply wagons more than twice. He brings war material from home but forages on the enemy—one cartload of enemy provisions equals twenty of your own because of transport costs.
A wise general forages on the enemy. Captured chariots should have their flags replaced with yours and be mingled with your own forces. Captured soldiers should be kindly treated.
The bottom line: Let your great object be victory, not lengthy campaigns. 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.
This chapter presents the famous hierarchy of military excellence. The best thing of all is to take the enemy’s country whole and intact—to shatter and destroy it is not as good. Supreme excellence consists of breaking the enemy’s resistance without fighting.
The ranking goes like this: The highest form of generalship is to balk the enemy’s plans. The next best is to prevent the junction of enemy forces. The next is to attack the enemy’s army in the field. The worst policy is to besiege walled cities, which takes three months just to prepare mantlets and movable shelters, and three more months to pile up mounds against the walls. A general who loses patience and launches his men like swarming ants will have one-third of his men slain while the town still stands.
The rule for when to fight based on numbers:Â If your forces are ten to the enemy’s one, surround him. If five to one, attack him. If twice as numerous, divide your army into two. If equally matched, offer battle. If slightly inferior, avoid the enemy. If completely outmatched, flee.
Three ways a ruler can bring misfortune upon his army: First, by commanding advance or retreat without knowing the army cannot obey—this hobbles the army. Second, by trying to govern an army the same way he administers a kingdom—this causes restlessness. Third, by employing officers without discrimination, through ignorance of military principles—this shakes the confidence of soldiers.
The five essentials for victory:Â He will win who knows when to fight and when not to fight. He will win who knows how to handle both superior and inferior forces. He will win whose army is animated by the same spirit throughout all ranks. He will win who, prepared himself, waits to take the enemy unprepared. He will win who has military capacity and is not interfered with by the sovereign.
The most quoted lines in the entire book:Â “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.”
The good fighters of old first put themselves beyond the possibility of defeat, then waited for an opportunity to defeat the enemy. Securing yourself against defeat lies in your own hands, but the opportunity to defeat the enemy is provided by the enemy himself—usually through his mistake.
The paradox:Â One may know how to conquer without being able to do it. Security against defeat implies defensive tactics; ability to defeat the enemy means taking the offensive. Standing on the defensive indicates insufficient strength; attacking indicates superabundance of strength.
The general skilled in defense hides in the most secret recesses of the earth. The general skilled in attack flashes forth from the topmost heights of heaven.
True excellence is not seeing victory only when it’s obvious to the common herd. To lift an autumn hair is no sign of great strength; to see the sun and moon is no sign of sharp sight. What the ancients called a clever fighter is one who not only wins but excels in winning with ease. His victories bring him no reputation for wisdom because the world never sees what he did—the enemy simply submitted before any bloodshed.
The victorious strategist only seeks battle after victory has been won. The one destined to defeat first fights and then looks for victory.
This chapter introduces the crucial concepts of direct and indirect methods. The control of a large force follows the same principle as controlling a few men—it’s just a question of dividing up numbers and instituting proper signals.
The core teaching: In all fighting, the direct method may be used for joining battle, but indirect methods will be needed to secure victory. There are only five musical notes, yet their combinations give rise to more melodies than can ever be heard. There are only five primary colors, yet their combinations produce more hues than can ever be seen. There are only five cardinal tastes, yet their combinations yield more flavors than can ever be tasted. In battle, there are only two methods of attack—direct and indirect—yet these two in combination give rise to an endless series of maneuvers.
Energy is like the bending of a crossbow; decision is like the releasing of the trigger. The onset of troops is like the rush of a torrent that rolls stones along in its course. The quality of decision is like the well-timed swoop of a falcon that strikes and destroys its victim.
Simulated disorder requires perfect discipline. Simulated fear requires courage. Simulated weakness requires strength. The clever combatant looks to the effect of combined energy, not requiring too much from individuals.
The famous metaphor:Â The energy of good fighting men is like the momentum of a round stone rolled down a mountain thousands of feet in height.
Whoever is first in the field and awaits the enemy will be fresh for the fight. Whoever is second and has to hasten to battle will arrive exhausted. The clever combatant imposes his will on the enemy but does not allow the enemy’s will to be imposed on him.
By holding out advantages, you can cause the enemy to approach of his own accord. By inflicting damage, you can make it impossible for him to draw near. If the enemy is taking his ease, harass him. If well supplied with food, starve him out. If quietly encamped, force him to move.
Appear at points the enemy must hasten to defend. March swiftly to places where you are not expected. You can be sure of succeeding in your attacks if you only attack places that are undefended. You can ensure the safety of your defense if you only hold positions that cannot be attacked.
The divine art of subtlety:Â Through it, you learn to be invisible and inaudible, holding the enemy’s fate in your hands. 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 the enemy’s.
The spot where you intend to fight must not be made known. The enemy will have to prepare against possible attack at several different points, distributing his forces. He will strengthen his van and weaken his rear, strengthen his left and weaken his right. If he sends reinforcements everywhere, he will everywhere be weak.
The water principle:Â Military tactics are like water. Water runs away from high places and hastens downward. In war, avoid what is strong and strike what is weak. Water shapes its course according to the ground; the soldier works out victory in relation to the foe. Just as water retains no constant shape, in warfare there are no constant conditions.
The difficulty of tactical maneuvering consists of turning the devious into the direct and misfortune into gain. Taking a long, circuitous route, enticing the enemy out of the way, and reaching the goal before him—this shows knowledge of the artifice of deviation.
The costs of forced marches:Â If you march a hundred miles to wrest an advantage, the leaders of all three divisions will fall into the enemy’s hands, and only one-tenth of your army will reach its destination. If you march fifty miles, you will lose the leader of your first division, and only half your force will arrive. If you march thirty miles, two-thirds will arrive.
An army without its baggage train is lost. Without provisions, it is lost. Without bases of supply, it is lost.
In war, practice dissimulation and you will succeed. Let your rapidity be that of the wind, your compactness that of the forest. In raiding and plundering be like fire, in immovability like a mountain. Let your plans be dark and impenetrable as night, and when you move, fall like a thunderbolt.
When not to attack:Â Do not advance uphill against the enemy. Do not oppose him when he comes downhill. Do not pursue an enemy who simulates flight. Do not attack soldiers whose temper is keen. Do not swallow bait offered by the enemy. Do not interfere with an army that is returning home. When you surround an army, leave an outlet free. Do not press a desperate foe too hard.
The general who thoroughly understands the advantages that accompany variation of tactics knows how to handle his troops. 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.
In the wise leader’s plans, considerations of advantage and disadvantage are blended together. If your expectation of advantage is tempered by allowing for disadvantage, you may succeed in accomplishing your essential schemes. If in the midst of difficulties you are always ready to seize an advantage, you may extricate yourself from misfortune.
There are roads which must not be followed. Armies which must not be attacked. Towns which must not be besieged. Positions which must not be contested. Commands of the sovereign which must not be obeyed.
The five dangerous faults of a general:
Recklessness, which leads to destruction (fighting blindly like a mad bull)
Cowardice, which leads to capture (fearing to take any risk)
A hasty temper, which can be provoked by insults
A delicacy of honor which is sensitive to shame (exaggerated sensitivity to slander)
Over-solicitude for his men, which exposes him to worry and trouble
When an army is overthrown and its leader slain, the cause will surely be found among these five dangerous faults.
This chapter provides practical advice on where to camp and how to read signs from the enemy.
Camping principles:Â When in mountain country, camp in valleys, not on heights. After crossing a river, get far away from it. Do not meet an invader in mid-stream; let half his army get across, then attack. In salt marshes, get through quickly without delay. In dry, level country, take an accessible position with rising ground to your right and on your rear, so danger is in front and safety behind.
All armies prefer high ground to low, and sunny places to dark. If you camp on hard ground, the army will be free from disease.
Reading enemy signs:
When the enemy is close and remains quiet, he’s relying on a strong position
When he keeps aloof and tries to provoke battle, he wants you to advance
Movement in trees shows the enemy is advancing
The rising of birds in flight signals an ambush
Startled beasts indicate a sudden attack is coming
High, sharp dust columns mean chariots are advancing
Low, wide dust means infantry is approaching
Humble words and increased preparations mean the enemy is about to attack
Violent language and driving forward mean he’s about to retreat
Peace proposals without a sworn covenant indicate a plot
When soldiers stand leaning on their spears, they’re faint from hunger
Too many rewards mean the enemy is at the end of his resources
Too many punishments betray a condition of dire distress
Leadership balance: 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. But if you are indulgent without enforcing authority, kindhearted without enforcing commands, incapable of quelling disorder, your soldiers become like spoiled children—useless for any practical purpose.
Six kinds of terrain:
Accessible ground can be freely traversed by both sides. Be first to occupy raised, sunny spots and guard your supply lines.
Entangling ground can be abandoned but is hard to re-occupy. If the enemy is unprepared, sally forth and defeat him. But if he is prepared and you fail, disaster follows.
Temporizing ground offers no advantage to whoever makes the first move. Even if the enemy offers bait, don’t stir forth. Retreat, enticing him, then attack when part of his army has come out.
Narrow passes should be strongly garrisoned if you occupy them first. If the enemy forestalls you, only attack if the pass is weakly garrisoned.
Precipitous heights should be occupied on raised, sunny spots. If the enemy gets there first, retreat and try to entice him away.
Distant ground with equal forces makes it hard to provoke battle.
Six calamities that arise from a general’s faults:
Flight: when one force is hurled against ten times its size
Insubordination: when soldiers are too strong and officers too weak
Collapse: when officers are too strong and soldiers too weak
Ruin: when higher officers are angry and give battle on their own from resentment
Disorganization: when the general is weak and his orders unclear
Rout: when the general can’t estimate the enemy’s strength
The general who knows these things and puts his knowledge into practice will win. He who knows them not will be defeated.
The jewel of the kingdom:Â The general who advances without coveting fame, retreats without fearing disgrace, whose only thought is to protect his country and serve his sovereign.
This chapter distinguishes nine types of ground and the appropriate tactics for each.
The nine grounds:
Dispersive ground is when you fight on your own territory. Here, soldiers are near home and may desert. Do not fight; inspire unity instead.
Facile ground is when you’ve penetrated only a short distance. Easy to retreat. Do not halt; keep close connection between all parts.
Contentious ground is ground whose possession brings great advantage. Do not attack; hurry to occupy it first.
Open ground gives both sides liberty of movement. Do not try to block the enemy’s way.
Ground of intersecting highways connects three states. Join hands with your allies.
Serious ground is when you’ve penetrated deep into hostile territory, leaving cities in your rear. Gather plunder to ensure supplies.
Difficult ground includes mountains, forests, marshes. Keep pushing on the road; do not encamp.
Hemmed-in ground is reached through narrow gorges with only tortuous paths for retreat. Use stratagem.
Desperate ground offers no escape. Fight, because you can only be saved by fighting without delay.
The snake principle:Â The Shuai-jan snake attacks with its tail if you strike its head, with its head if you strike its tail, and with both if you strike its middle. An army can be trained to respond this way. The men of Wu and Yueh are enemies, yet crossing a river in the same boat during a storm, they help each other like left hand helping right.
The key strategy:Â Throw your soldiers into positions from which there is no escape, and they will prefer death to flight. If they face death, there is nothing they may not achieve. Soldiers when in desperate straits lose the sense of fear. If there is no place of refuge, they will stand firm. If there is no help for it, they will fight hard.
Rapidity is the essence of war:Â Take advantage of the enemy’s unreadiness. Make your way by unexpected routes. Attack unguarded spots.
Five ways to attack with fire:Â Burn soldiers in their camp. Burn their stores (provisions, fuel, fodder). Burn their baggage trains. Burn their arsenals and magazines. Hurl dropping fire among the enemy (flaming arrows).
The proper season is when the weather is very dry. The special days are when the moon is in certain constellations that bring rising wind.
When fire breaks out inside the enemy’s camp, respond immediately with an attack from without. If fire breaks out but the enemy’s soldiers remain quiet, wait—do not attack. They’re ready for you. When the flames reach their height, follow up with an attack if possible. If you can make an assault with fire from without, do not wait for it to break out within.
Start a fire to windward. Do not attack from the leeward.
Water vs. fire:Â Water can intercept an enemy but cannot destroy his supplies like fire can.
The final warning:Â Anger may change to gladness, vexation to contentment. But a kingdom once destroyed can never come again into being. Nor can the dead ever be brought back to life. 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.
Raising a hundred thousand men and marching them great distances causes heavy loss to the people. Wars can drag on for years. To remain in ignorance of the enemy’s condition simply because you grudge a hundred ounces of silver for spies is the height of inhumanity. Such a person is no leader of men, no help to his sovereign, no master of victory.
Foreknowledge cannot be obtained from spirits, from induction, or from calculation. It can only be obtained from other men.
The five kinds of spies:
Local spies are inhabitants of the enemy’s district, employed by kind treatment
Inward spies are enemy officials won over by rich presents
Converted spies are enemy spies you catch and turn to your own service
Doomed spies are your own agents who are fed false information and sent to the enemy, knowing they will be captured
Surviving spies are those who bring back real news from the enemy’s camp
When all five kinds are at work, none can discover the secret system. This is called “divine manipulation of the threads.”
Rules for handling spies:Â Have no more intimate relations with anyone than with spies. No one should be more liberally rewarded. No business requires greater secrecy. Spies cannot be usefully employed without intuitive sagacity. They cannot be properly managed without benevolence and straightforwardness. Without subtle ingenuity of mind, one cannot make certain of the truth of their reports.
The converted spy is the most important. Through his information, you can acquire and employ local and inward spies. Through him, you can cause doomed spies to carry false tidings. Through him, surviving spies can be used on appointed occasions.
Historical examples:Â The rise of the Yin dynasty was due to I Chih, who had served under the Hsia. The rise of the Chou dynasty was due to Lu Ya, who had served under the Yin.
The final line:Â Spies are a most important element in war, because on them depends an army’s ability to move.
Know yourself and know your enemy. This is the most repeated lesson. Self-awareness and understanding others are the foundations of all success.
The best victory is winning without fighting. Break resistance without conflict. Persuade, outmaneuver, or make fighting unnecessary.
All warfare is based on deception. Don’t show your hand. Appear weak when strong, appear strong when weak.
Speed matters more than perfection. Long delays drain resources. Quick, decisive action beats prolonged struggle.
Adapt like water. Water has no constant shape. Your plans shouldn’t either. Change with circumstances.
Plan before you act. The general who makes many calculations wins. The one who makes few loses.
Know when to fight and when not to. Not every battle is worth fighting.
Use indirect approaches. The unexpected path often wins.
Read the signs. Pay attention to what people do, not what they say.
Treat your people well but maintain discipline. Soldiers treated like children will follow you anywhere. But without enforcement of commands, they become useless.
