Original Text
Sun Tzu said: Generally, when deploying troops for battle, one must mobilize a thousand war chariots, a thousand supply wagons, and assemble a hundred thousand fully armed soldiers, while also transporting provisions over a thousand miles. Thus, the various expenses at home and abroad—including costs for entertaining envoys and strategists, materials like glue and lacquer for repairing equipment, and maintenance of chariots and armor—amount to enormous sums daily. Only after these preparations are made can the hundred-thousand-strong army march forth.
Therefore, in military operations, swift victory must be sought. A prolonged campaign exhausts the army, blunts its edge; storming fortresses drains its strength; extended operations abroad burden the state's resources heavily. If the army is weary, its spirit broken, its numbers depleted, and its supplies exhausted, other feudal lords will seize the opportunity to strike. At that point, even the most resourceful strategist cannot salvage the crisis. In actual warfare, one only hears of commanders lacking brilliant tactics to achieve quick victory, never of those skillfully directing prolonged campaigns. There has never been a case where a protracted war benefited the state. Thus, those who do not fully understand the harms of war cannot truly grasp its advantages.
The skilled commander does not levy troops repeatedly, nor transport supplies multiple times. After one requisition from home, he seeks provisions from the enemy, thus the army's food and resources suffice for battle.
The impoverishment of a state due to military campaigns stems from long-distance transport. Long-distance transport inevitably drains the people’s wealth. Where armies pass, prices soar; soaring prices deplete the people’s resources; depleted resources lead to heavier taxes and corvée. On the battlefield, strength is exhausted; at home, resources are drained. The people’s property is diminished by seven-tenths due to war. The state’s treasury also suffers a six-tenths loss from the damage and repair of chariots, the fatigue of horses, the production and replenishment of armor, helmets, arrows, crossbows, spears, shields, and large shields, as well as the requisition and deployment of supply wagons.
Therefore, a wise commander always seeks to obtain supplies from the enemy. One zhong of grain taken from the enemy equals twenty zhong transported from home; one dan of fodder consumed from the enemy equals twenty dan transported from home.
The reason soldiers fight fiercely to kill the enemy is that they share a common hatred. The reason they dare to seize the enemy's supplies is that they receive material rewards. Therefore, in chariot warfare, whoever captures more than ten enemy chariots is rewarded first. The captured chariots should immediately be marked with our own flags and mixed into our formation. Captured enemy soldiers should be treated kindly and comforted, so that they are willing to submit and serve us. This is what is meant by defeating the enemy and growing stronger in the process.
Therefore, in warfare, the most crucial and advantageous approach is swift victory, while prolonged conflict is the least desirable. A commander who truly understands the art of war and deeply grasps its advantages and disadvantages holds the power over the people's lives and the nation's security.
Commentary
This chapter discusses the close dependence of warfare on human, material, and financial resources, primarily addressing the harm prolonged campaigns inflict on a nation. It proposes the principle of swift victory—"speed in war is valued, not prolonged operations"—and outlines operational guidelines such as "procure provisions from the enemy" and "grow stronger by defeating the enemy."
The essence of the chapter on warfare lies in discussing the impact of war on a nation's economy. Sun Tzu addresses these issues from the perspective of the dominant side in war. If we also consider the problems from the dominant side, the conclusion would evidently be the same as Sun Tzu's two thousand years ago.
Example Interpretation
Zhou Yafu Cut Off the Enemy's Supply Route
Before troops move, provisions go first. Provisions are not only the prerequisite for an army's victory but also the very foundation of its survival. In war, how to secure provisions and other supplies for the army is equally crucial to achieving victory.
Not long after Emperor Jing of Han ascended the throne, Liu Pi, the Prince of Wu, colluded with six other feudal princes who had long been plotting rebellion. Commanding an army of 200,000, they marched straight toward the capital. Emperor Jing appointed Grand Commandant Zhou Yafu as the commander of the vanguard forces to suppress the rebellion.
Knowing the danger of the campaign, Zhou Yafu took only a few trusted soldiers and rode a swift light chariot, hurrying toward Luoyang. Upon reaching Bashang, he received secret intelligence: Liu Pi had hired many assassins, setting up ambushes along the Xiaoshan-Mianchi route from the capital to Luoyang, ready to strike down any general the imperial court sent to the front.
Zhou Yafu decisively avoided the treacherous Xiaomian terrain, took a detour, and arrived safely in Luoyang. He then advanced to Suiyang, captured the city of Changyi north of it, dug deep trenches, built high walls, and cut off Liu Bi's northward route. Subsequently, he seized the Huaisi Estuary, severing Liu Bi's grain supply line.
After Liu Pi's army was blocked from advancing north, they turned around and threw all their strength into attacking Suiyang City. However, Suiyang City was extremely well-fortified, with ample food and weapons inside. The defending general Liu Wu, coordinating with Zhou Yafu, led the Han army to defend the city with desperate resolve. After suffering repeated defeats at the walls of Suiyang, Liu Pi then shifted to attack Changyi, seeking a decisive battle.
Zhou Yafu held his ground, refusing to engage in battle, in order to deplete Liu Bi's supplies. Liu Bi could do nothing against him.
Over time, Liu Pi, with his supply lines cut, faced a shortage of military provisions and wavering morale, and began to panic. He gathered all his elite forces, staked everything on a single throw, and launched a massive, fierce assault on the stronghold defended by Zhou Yafu. The battle was exceptionally intense.
In his assault, Liu Pi employed a strategy of feinting east while attacking west. On the surface, he sent a large force to strike the southeast corner of the Han fortifications, but in reality, he had his elite troops hidden, ready to attack the northwest corner. However, Zhou Yafu saw through Liu Pi's ruse. When the defenders at the southeast corner repeatedly sent urgent requests for reinforcements, Zhou Yafu not only refused to send troops there but instead moved his main force to the northwest corner. Sure enough, amid the clamor of drums and gongs, Liu Pi suddenly waved his command flag, unleashed his finest soldiers, and launched a thunderous assault on the northwest corner of the fortifications, each wave fiercer than the last.
From dawn until night, the fierce battle raged on. Liu Pi's army suffered heavy losses before the fortifications, their morale completely shattered. With their food supplies exhausted, they had no choice but to retreat. How could Zhou Yafu let such a golden opportunity slip? He pressed the advantage, ordering his troops to charge. The rebel forces were utterly defeated. Seeing the situation was hopeless, Liu Pi fled south of the Yangtze River with his son and several thousand elite guards, only to be killed soon after by the King of Dongyue. Zhou Yafu advanced triumphantly, crushing the remaining six kingdoms. The Kings of Chu, Jiaoxi, Jiaodong, Zichuan, Jinan, and Zhao all committed suicide one after another, thus ending the "Revolt of the Seven Kingdoms." From the very start of the campaign, Zhou Yafu seized the key to victory: cutting off the enemy's retreat and supply lines, then slowly wearing down their fighting spirit. His tactical execution was precise, and that was why he achieved such a great victory.