The Book of War: The Articles of Suntzu

This summary was created by AI (Konspekto) from the text of this edition. Quotes are checked against the book text automatically.

In brief

How can an army achieve victory without exhausting the resources on which its survival depends? The answer rests on preparation, informed judgment and restraint rather than a willingness to fight at any cost. A commander must compare leadership, discipline, resources and operating conditions before deciding whether an advantage exists. That assessment guides action, but it cannot determine every move in advance: plans must change with circumstances.

Concealing intentions and misleading the enemy can create openings, while coordinated forces can exploit weaknesses before the opponent responds. These advantages matter only if the army retains the capacity to use them. Prolonged campaigns consume the state’s resources, and excessive haste can leave troops exhausted or separated from essential supplies. Movement therefore requires attention to readiness as well as speed.

Terrain further limits what an army can safely attempt. Different positions call for different decisions about advancing, fighting or withdrawing, and military judgment may require rejecting an order that would produce defeat. Even destructive methods such as fire attacks must be judged by the advantage they can actually secure. Reliable intelligence supports these decisions throughout.

Spies provide knowledge that helps commanders avoid costly uncertainty, while secrecy prevents the enemy from gaining a comparable advantage. Victory thus depends on continually matching action to the enemy’s condition while preserving the strength needed to carry it through.

Key ideas

1. Victory depends on assessing the opposing armies' leadership, discipline, numbers and resources alongside terrain and the enemy’s condition. A decision to fight must rest on a credible military advantage, not anger or a ruler’s insistence (p. 17–57, 67–74).
2. Hidden intentions, deception and a changing combination of direct attacks and unexpected moves can divide enemy forces and reveal a vulnerable point. Clear signals and organized units allow concentrated forces to exploit the opening while it lasts (p. 17–46, 58–67).
3. Prolonged warfare depletes public resources and exhausts soldiers, while overambitious marches can leave too few troops ready for battle. Speed is useful only when commanders maintain fighting strength and supplies and avoid attacks whose gains cannot be sustained (p. 17–23, 34–46, 58–74).
4. Terrain shapes safe movement and determines when fighting, withdrawal or avoiding a siege is appropriate. As the enemy’s position and circumstances change, commanders must adjust their methods rather than repeat earlier successes or follow orders unsuited to the situation (p. 34–67).
5. Effective decisions depend on understanding both armies and discovering enemy intentions through observation and human sources. Enemy spies brought into one’s service are especially useful because they can support other intelligence operations; secrecy denies the opponent a similar advantage (p. 17–74).

Summary by chapter

I. Preliminary Reckoning—II. Operations of War (p. 17–23)

Prospects of victory depend on comparing the rulers, commanders, natural advantages, discipline, troop numbers, training and fairness of the opposing sides. Effective command also requires social unity, sound judgment of conditions, capable leadership and orderly organization.

Even a favorable plan must change with circumstances. Misleading the enemy about strength and position, separating united forces and striking weak or unexpected points can create openings, provided the plan remains secret.

Long campaigns wear down troops and state finances, leaving the country exposed. A capable commander therefore seeks a quick victory, uses enemy supplies to feed the army and rewards captors who add to its strength.

III. The Attack by Stratagem—V. The Spirit of the Troops (p. 24–34)

Defeating an enemy without battle is better than laying siege. Tactics should reflect relative strength, while a ruler who overrules military judgment weakens the army; knowing both sides helps a commander assess the chance of victory.

A skilled army protects itself from defeat and attacks when the enemy becomes vulnerable. It estimates its prospects from the land, its produce and its population rather than relying on chance in battle.

Subdivisions and signals allow large forces to act together. Alternating direct attacks with surprises, using disciplined deception and exploiting openings promptly can turn the troops' fighting spirit into decisive force.

VI. Emptiness and Strength—VIII. The Nine Changes (p. 34–46)

An army that arrives first preserves its strength. Feints and concealed plans can spread the enemy thin, allowing a concentrated attack on a weak point; tactics must then change with the enemy’s position rather than repeat an earlier success.

Maneuvers must take distance, supplies and fatigue into account, because a forced march may leave too few troops fit to fight. Common signals keep forces coordinated, and an attack timed for the enemy’s fatigue saves strength.

Terrain and circumstances may justify avoiding a road, battle or siege despite orders. A commander should prepare for attack, consider dangers as well as opportunities and avoid rashness, undue caution, irritability, inflexibility and excessive concern for the troops.

IX. Movement of Troops—X. Ground (p. 47–57)

In mountains, at rivers, through marshes and on plains, troops should seek safe, elevated positions and avoid dangerous crossings. Features of the terrain, dust, wildlife and enemy conduct can disclose an ambush, an intention or a weakness.

Each of the six kinds of ground demands its own response. An unfavorable match between troops and opponents, weak command, disobedient officers or unclear orders can turn an opportunity into defeat.

A commander must judge the enemy, the army’s own troops, the ground and the timing together. Care for soldiers must be paired with discipline, and the decision to fight must rest on military grounds even when that means disobeying the ruler.

XI. Nine Grounds (p. 58–67)

The nine kinds of ground demand different tactics: avoid fighting at home or lingering near a border, obtain supplies deep in enemy territory, leave difficult ground quickly and fight when delay would be fatal.

Speed and surprise help sustain the army, while food, rest and careful planning preserve its strength. When escape is impossible, a shared desperate position can unite the troops and make them fight harder.

A commander should conceal plans, direct the army as a single force, learn the terrain and the enemy’s intentions, keep enemy forces from joining and exploit openings without delay.

XII. Assault by Fire—XIII. The Employment of Spies (p. 67–74)

A fire attack requires suitable weather, prepared equipment and a response suited to the enemy’s behavior. Fire and floods are useful only when they bring victory or secure possession; otherwise the enemy can recover.

Because war is costly and its losses cannot be reversed, rulers and commanders should fight only for an attainable advantage or to defend the state, not from anger. Refusing to pay for spies leaves them without needed knowledge.

Knowledge of the enemy comes from local informants, enemy officials, enemy spies who have been turned, agents sent to spread false information and spies who return. Turned spies help make the other agents effective and deserve generous treatment.

How to apply it

• Compare leadership, discipline, forces, resources and terrain before committing troops, and withhold battle when the military assessment indicates defeat, even if a ruler orders it.
• Conceal intentions and use misleading movements to divide enemy forces, then coordinate concentrated units against an exposed weakness.
• Set marching speed according to troop readiness and supply requirements so that rapid movement does not destroy the army’s ability to fight.
• Revise routes and tactics when terrain or enemy dispositions change rather than treating an earlier success as a fixed model.
• Assess the attainable benefit before launching an attack, including an attack by fire, and refrain when no advantage is available.
• Gather intelligence through observation and informants, protect its secrecy, and reward converted enemy spies generously because they help other intelligence operations succeed.

Quotes

Wherefore, with regard to the foregoing, considering that with us lies the advantage, and the generals agreeing, we create a situation which promises victory; but as the moment and method cannot be fixed beforehand, the plan must be modified according to circumstances. (p. 19)

For, while quick accomplishment has been known to give the victory to the unskilful, the skilful general has never gained advantage from lengthy operations. In fact, there never has been a country which has benefited from a prolonged war. (p. 21–22)

The army that conquers makes certain of victory, and then seeks battle. (p. 30)

The flow of water is regulated by the shape of the ground; victory is gained by acting in accordance with the state of the enemy. The shape of water is indeterminate; likewise the spirit of war is not fixed. (p. 39)

About the author (AI note, not from the book’s text)

Sun Tzu, also known as Sun Wu, is traditionally identified as an ancient Chinese military strategist. He is credited with The Art of War, a treatise on military strategy.

About this edition

• Author: Sun Tzu
• Title: The Book of War: The Articles of Suntzu
• Edition: John Murray, London, 1908
• Translator: Everard Ferguson Calthrop
• Edition language: English
• Original language: Classical Chinese
• Content pages: p. 17–74
• Rights: Public domain