Chapter 2 - Waging War | The Art of War by Sun Tzu

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Laying Siege Exhausts Strength

When you engage in actual fighting, if victory is long in coming, then men's weapons will grow dull and their ardour will be damped. If you lay siege to a town, you will exhaust your strength.

In 1779, the Spanish and French attempted to seize a British fortress in the Siege of Gibraltar during the American War of Independence.

Despite assaulting the city with heavy guns, ships and thousands of troops, the British held firm retaliating with heated shots from cannons, causing mushroom clouds and forcing the enemy to finish the assault. After nearly four years of fighting, the Spanish and French forces retired and Gibraltar was held. It was the longest siege the British Armed Forces ever took part in.

Soldiers are not machines and this is one of the reasons war should be short and sharp. If possible, a siege strategy should be avoided as victory in war is achieved with soldiers that are passionate and prepared for battle. Lengthy campaigns will eventually wear them out.


Again, if the campaign is protracted, the resources of the State will not be equal to the strain.

Early in the 5th century, the Roman Empire was old and weakening. As the Romans struggled to hold Britain, new people came to England to settle from the area of modern Germany. They were the Anglo-Saxons and many of them first came to England as mercenaries in the Roman army. As the Romans withdrew, the British leaders hired them for protection. The mercenaries were helpful while they were paid, but when the money ran out they rebelled against the British.

War has a cost. The state runs the risk of running out of funds if there is an endless cost of weapons, logistics and wages.

When Your Weapons Are Dulled

Now, when your weapons are dulled, your ardour 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.

In 1941, the Germans launched Operation Barbarossa – their name for the invasion of the Soviet Union. They were so confident of a quick victory that they did not prepare for the possibility of winter warfare in Russia. The German armed forces lacked the necessary supplies such as winter uniforms, and the campaign was delayed due to bad weather and flooding.

The failure to achieve victory before the Russian winter set in was a contributing factor in losing the war. Soon after, the Germans also faced advances from allies that took advantage, such as the United States and Great Britain.

When weapons are used up, troops are exhausted and supporting resources are gone you are in a position of great weakness. Such situations should be seen long before they occur, with enough time to allow them to be actively avoided.

Haste In War and Cleverness

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

Fabius Cunctator the Roman general took on Hannibal by judging that Rome could endure a conflict for a longer period of time than Hannibal’s forces. He thought that a long campaign in a country away from home would affect Hannibal’s isolated army more than his own.

By employing the Fabian strategy of avoiding pitched battles with a set time and place, Fabius instead wore down his enemy through a war of attrition by harassing them through battles to interrupt supplies and upset morale.

Fabius harassed the foraging parties, limiting Hannibal's ability to attack, while conserving his own military force. He also scorched the earth to prevent Hannibal's forces from obtaining food and other resources.

Time is needed to think and prepare, but you must also be aware that delay has costs as whatever you do, your resources are being spent.

Prolonged Warfare

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

During the American Revolution, General George Washington suffered early defeats and soon realised that he could not win pitched battles against the superior British forces. He informed the Congress that he planned to change his strategy, avoiding going head-to-head with the British and instead seeking a long-drawn-out war.

By giving way on the fixed battlefield, Washington saved his own army from destruction until the circumstances changed. There were thousands of casualties on both sides. When the French later assisted, it allowed for an American victory at Yorktown, which led to the British negotiating an end to the conflict.

A prolonged battle is not a smart way to fight, even if it finally exhausts the enemy. A war of attrition is expensive and costs are felt long after the fighting has ended.

The Evils of War

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

One of the most destructive conflicts in European history was The Thirty Years' War, a series of wars in Central Europe between 1618 and 1648. The end result was the death of approximately 8 million people.

The war devastated entire regions. Famine and disease led to high mortality in many parts of Central Europe. Regular soldiers in fighting armies and mercenaries looted or acquired money through extortion to get operating funds. This inflicted yet more hardship on the populations of territories that were occupied. The end result of the war was the bankruptcy of most of the states taking part in the combat.

It is possible to profit from war, plundering as you go being one method, although this can still have a cost through later revenge.

Taking pleasure in harming others is an evil trait. Evil people do find their way into armies as this provides a means to their ends. Beware those who fight for their own desire rather than for the love of their nation and contemporaries.

The Skilful Soldier

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

Julius Caesar was extremely successful as a Roman military commander due to his energetic ability to get things done. He could do everything with astonishing speed and lived at a quicker tempo than the people who he had to compete with. This gave him an enormous advantage, allowing for a greater opportunity for unexpected, unpredictable actions. This clear vision was Caesar's exceptional characteristic. It was the product of remarkable brain-power led by an unyielding determination.

During the Great Roman Civil War, Caesar went to deal with Pharnaces II, a king who had taken a city that was a Roman ally.

Caesar’s unusually swift approach brought war quickly and when the clash occurred Pharnaces’ forces were completely overpowered. His victory was so rapid and comprehensive that when he wrote to his friend in Rome about the war, Caesar said: "Veni, vidi, vici" (I came, I saw, I conquered).

The value of time, specifically being slightly ahead of your opponent, has often counted for more than numerical superiority. After war has been declared, a strong army doesn’t wait for supplies or reinforcements. It uses the element of surprise to swiftly invade, creating momentum, immediately gaining ground.

Bringing War Material From Home

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

The Black Prince of England took part in the burning and pillaging of towns and farms during the Hundred Years’ War in France. It was known as a chevauchée strategy. These rapid pillaging raids plundered the countryside which resulted in the local authority being undermined and hostages being captured. A chevauchée lived off the land, also stealing livestock as well as causing general mayhem. 

It is always better to use your own weapons which you know well but for food and other supplies, it can be very helpful to capture these from your enemy.


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.

In an attempt to deepen anger against Germany and her people, in 1940 an "Anger Campaign” was devised by the United Kingdom Ministry of Information. This was done to increase resolve against the Germans as until then, the British had little sense of real hostility towards the average German. In a series of broadcasts on the radio, a chief diplomatic advisor said that Germany was a nation raised on "envy, self-pity and cruelty" which had "finally given expression to the blackness of the German soul".

Anger has a chemical effect on the body and the brain. Fear is forgotten and adrenaline courses through the muscles. It provokes a natural state for fighting.

Seething anger also motivates troops effectively over the long term. The atrocities of the enemy may be held up and amplified so that they create a longer-term hatred that drive the army on until victory is gained.

Treat Captives Kindly

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.

The Romans were experts at successfully integrating the population of a conquered land.

After invading a state, they would conquer it through non-violent means if possible, being lenient but backed by overwhelming force. They would allow freedom of religion so long as the people also give loyalty to the emperor. The Romans would build roads, aqueducts and promote trade to ensure lots of people got rich.

As the Romans moved in to the same territory, their high-class lifestyle became aspirational to the youth and within a couple of generations the original culture was consigned to folk law.

If war ever took place, as a Roman ally the conquered state was expected to send men to fight alongside Rome. In most cases Rome managed to persuade troops from the conquered kingdoms that their best interests lay in fighting on behalf of the Roman Empire rather than remaining loyal to their own nation.

Ensure your troops do not become animals by ensuring they treat prisoners humanely. When the enemy's possessions have been taken, they may be forgiven.

Soldiers who are captured and abused will hate you forever, as will their friends and family. Treat them well and they will work with you more easily.

The Object Is Victory, Not Glory

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

General Douglas MacArthur was appointed supreme Allied commander by the US President in 1945. He accepted the formal surrender of Japan, and for the following six years, he remained in the country to command the occupying Allied forces there and to supervise the reconstruction of Japan.

On the subject of conflict, he said: “War's very object is victory, not prolonged indecision. In war there is no substitute for victory.”

The goal of war is to win, not to trounce everyone and everything. The objective is to defeat the opponent, not to fight forever. 

Whilst there may be glory in battle there is also huge cost. Be careful not to let glory become the reason for battle. Stories of heroic courage are good for recounting later but they are not good for the nation when an easier victory can be gained.

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