How Wars Are Won: The 13 Rules of War-From Ancient Greece to the War on Terror

How Wars Are Won: The 13 Rules of War—From Ancient Greece to the War on Terror Click here to purchase from Barnes & Noble. Click here to purchase from

Introduction: The New Kind of War

The attack on the World Trade Center and Pentagon on September 11, 2001, dramatically changed the face of war. Suddenly war ceased to be primarily an enterprise employing military weapons against expectant armies, and changed to include lethal blows with civilian devices against innocent people.

This is a new kind of war in that no warriors previously had employed such a weapon, airliners loaded with passengers and jet fuel, but it is also the most ancient kind of war in that the strikes were ambushes, a tactic used in war from Stone Age times onward. Ambushes are designed to inflict the most damage at the least cost, to hit unwary, vulnerable targets, preferably those without means of defense.

September 11 will therefore go down in history as the moment when the world ceased to think of warfare exclusively as conventional clashes of massive, sophisticated weapons on the battlefield, and reverted to seeing war in its rawest, truest, and oldest form, characterized by small groups of warriors striking by surprise, or at night, against the actual or psychological rear of the enemy. Ravaging defenseless civilians, hit-and-run raids, sudden assaults on ill-defended places, hiding in inaccessible lairs, all these and more are the centuries-old elements of irregular warfare, of a strategy of the snare and of refusal to meet the main military strength of the enemy in open battle. The specific ancient rule the terrorists followed is to avoid the enemy’s strength and strike at weakness.1

Other terrorists will surely employ other rules of war by innovating other techniques of engagement, and using other devices to carry out their aims. Since the rules the terrorists use are universal, the civilized world must use the same rules to defeat them. The distinction now is that the rules and tactics will be played out in a much different fashion and in much different arenas than were seen in the huge wars and battlefields of the twentieth century.

Future wars are likely to be more limited, more specific in purpose. They will likely resemble guerrilla operations. Such conflicts are now largely being conducted by disaffected groups or factions within states, such as the Basques in Spain, the Tamils in Sri Lanka, and various rebel groups in Colombia. But the irregular methods that characterize these struggles---and have marked partisan war since prehistoric times---are being refined into a radically new type of warfare that pays little attention to national boundaries or to the old rules of orthodox war.

In coming to terms with the motives of the terrorists, we will do well to remember that war is essentially a political act to secure some aim. This was as true in Paleolithic times as it is today. One tribe ousting another from a hunting ground 20,000 years ago was executing a political act no less than the Allies preventing Germany from conquering Europe in World War II.

Likewise, the United States fought the Persian Gulf War of 1991 to keep Saddam Hussein from getting control of the oil supply of the Middle East. The purpose was not, as was advertised by the first Bush administration, to preserve the freedom of the autocratic little oil sheikdom of Kuwait.

This connection of war with politics is frequently misunderstood. Yet war is a military act only to the extent that military forces are needed to carry out a nation's political goal. The most memorable quotation from Carl von Clausewitz, the nineteenth-century Prussian author of the influential study, On War, is “war is only a continuation of state policy by other means.”2 That’s why the French premier in the First World War, Georges Clemenceau, said "wars are too important to be left to the generals." There can be no more graphic an example of war as politics than the destruction of the World Trade Center and the dreadful damage to the Pentagon.

The attack of September 11 focused attention on partisan or unorthodox war. But no matter what kind of war we face in the future, whether from terrorists or more traditional armed forces, in formulating effective responses, we can draw lessons and devise tactics using military rules or maxims whose origins go back beyond recorded time. The key defining feature of terrorist war is surprise, and we may not be able to predict exactly where or how our enemies will strike in the future. But we can understand their methods and techniques, and we can construct systems to defend against their blows and root them out of their holes.

Even before the terrorist strikes, war had changed profoundly in recent years. By the mid-1990s, military planners had determined that massive, world-scale wars no longer could be fought. The Persian Gulf War of 1991 showed that modern conventional weapons had become so accurate and so deadly that human beings would simply not be able to survive in appreciable numbers on traditional battlefields. With the subsequent completion of the satellite-directed Global Positioning System or GPS, the vulnerability of troops on the battlefield has become even greater because bombs and missiles can be sent with almost pinpoint accuracy to practically any spot on earth.

This means that the huge weapons and massive collisions of millions of men in battle, which characterized the two world wars 1914-1918 and 1939-1945, have now passed away.

The development of nuclear weapons from 1945 onward had already created enormous doubts about the possibility of fighting large wars. When the U.S. and the Soviet Union came within an eye blink of nuclear confrontation in 1962, during the Cuban missile crisis, every responsible person realized that nuclear weapons could not be used in war. Any nuclear strike would lead to counterstrikes that could accelerate beyond human capacity to control. This reality forced people everywhere to step back from the abyss.3

But only since the Gulf War have military leaders finally abandoned the concept that wars could still be fought between formal armies arrayed against each other using conventional or nonnuclear weapons. Traditional fire-and-maneuver tactics of individual military units, whether infantry, artillery, armor, or combinations of the three are now out of date. Today in almost any environment, including mountains, troops massed in even small groups are extremely vulnerable. Even if masked, they can usually be seen by aerial photographs, satellite scanners, unmanned aerial vehicles (UAVs), aircraft, or helicopters. Once detected, they can be precisely located by GPS, and hit with bombs, missiles, or shells directed by laser, infrared, acoustic, or radar homing signals.

The vulnerability of traditional military units has led to a great deal of deliberation as to how military operations can be carried out in the future. The most obvious casualty has been the idea of any war between comparably or equally armed opponents. In other words, direct collisions like those between the Russians and the Germans in 1941-1944 could have only one outcome under present-day conditions: each side would inflict immense casualties, immobilize the other, and bring about stalemate.

Another fact became evident in the Persian Gulf War: a nation like the United States with leading-edge or state-of-the-art military technology can destroy in short order an opponent with less-advanced technology. In the gulf, the Iraqi forces, deploying weapons a generation behind American arms, were virtually eradicated in a hundred hours.

At first blush, the overwhelming superiority of American military power seemed to ensure that nobody henceforth could seriously or effectively challenge any American move. With the demise of the Soviet Union in 1991, no comparably equipped military organization existed in the world, and none was being contemplated.4 But as we learned in the attacks of September 11, American military superiority did not in fact make the U.S. immune either to attacks or to military pressure.

We experienced a vivid glimpse into the uncharted future from the U.S. debacle in Somalia. Somalia was a failed state that had degenerated into anarchy caused by internecine conflict among warlords, and was stricken with famine by 1992. In an effort to ameliorate the famine, the United States began shipping in thousands of tons of food, and landed troops to ensure fair distribution. More ominously from the viewpoint of the Somali people, the U.S. also commenced a program of “nation-building” in 1993, seeking to create a country in the image of the United States. Nations, however, must evolve out of the genius of their own people. Outsiders, no matter how well-intentioned, cannot impose their values and their institutions on a people who have no knowledge of them nor experience in their development or implementation.

The untenable situation came to a head when clansmen ambushed U.S. Army Rangers trying to rescue a downed helicopter crew in Mogadishu on October 3, 1993. They killed eighteen Americans, wounded seventy-three, and dragged the body of an American through the streets by ropes. The attack demonstrated perfectly how a guerrilla trap can be sprung. The Rangers did not possess armor, and this contributed greatly to their losses. However, even heavy weapons are no guarantee of victory for a unit isolated in the midst of a hostile city. In tight urban areas, attackers can find ample opportunities to approach armored vehicles and destroy them with unsophisticated weapons (like satchel charges of explosives).5

It’s only a small step in theory, though a vast leap in magnitude, from the murder of eighteen on the streets of Mogadishu in 1993 to the murder of thousands in the towers of Manhattan in 2001. In both cases, our opponents found ways to shun American military strength and strike directly at American institutions and people. The lesson the Somalis taught was adapted by the Middle Eastern terrorists who attacked on September 11.

The terrorists came, as it were, under the defensive shield of the United States. By seizing commercial aircraft on routine flights, they managed to avoid suspicion until they diverted the planes toward New York City and northern Virginia, allowing them enough time to hit the targets before the military’s defensive system could respond. If the terrorists had used military aircraft and approached from the Atlantic Ocean, they would have been spotted at once and shot down.

The terrorists thus neutralized or evaded existing safeguards. An early example of the same principle is the Battle of Hastings in 1066. William of Normandy used weapons unfamiliar to the Anglo-Saxons to conquer the English king Harold and seize all of England. Most historians have held that Harold lost because his army was exhausted by fighting a battle with Norwegians in northern England only days before William landed on the south coast. This is not true. Harold lost because his forces were armed with pikes, axes, and swords, whereas William’s army possessed two superior weapons---the bow and armored cavalry. Nowadays we would call Hastings a clash between asymmetrical armies. In other words, William conquered England because the new weapons his forces used neutralized the defenses of the Anglo-Saxons.

France and the United States failed in their efforts to control Vietnam 1945-1975 for much the same reason that Harold failed at Hastings. Both countries tried to fight a traditional or conventional war against the Vietnamese Communist forces, but the Communists insisted on fighting a guerrilla war. That is to say the Vietnamese used different weapons, and with these weapons they were superior. They, like the September 11 terrorists, eluded strength and struck at weakness.

In most cases the Vietnamese refused to engage in pitched battles, because they knew they would lose them, since they possessed few heavy weapons. Instead, they adopted a policy of ambushing supply columns, surrounding and annihilating small outposts, and making surprise strikes at night on enemy installations. When French or American search-and-destroy missions went into the field, the Vietnamese fought long enough to inflict losses, but then vanished into the forests. Their methods inflicted a steady and unrelenting drain on manpower as well as on the resolve of the French and American people.

The Vietnamese never won a major military victory against the Americans (though they did against the French at Dien Bien Phu in 1954). But they did not have to. The morale of the people at home was their real target. When opposition at home became overwhelming, the French and American governments withdrew.

Although, as the examples above show, the methods or techniques of war must be tailored to existing challenges, warfare itself has followed the same set of rules or maxims from the Stone Age to the present. This is because the aim of war is constant. War is an act of violence to impose one’s will on another. It is an organized effort by a cell, band, tribe, nation, or coalition to force another group to do what it does not want to do.

The purpose of this book is to elucidate these key rules of war, identifying along the way those that are likely to be most relevant in future combat.6 Although conditions, arms, and the ways soldiers fight have varied greatly over the millennia, the problems commanders face and the solutions they reach are fundamentally identical. The method Alexander the Great employed to defeat the Indian king Porus in 326 B.C. is the same method a company of soldiers can use to win a firefight today.

A commander must decide which rule must be applied to solve a particular problem, and that solution must vary according to the particular circumstances the commander faces. All the rules of war are consistently valid, but in any given situation following one may bring victory, while following another would bring defeat.

Remarkably enough this has not always been understood. Antoine-Henri Jomini, a Swiss officer who served in the Napoleonic wars and who wrote a widely heralded interpretation of Napoleon Bonaparte’s methods, said Napoleon won quick, decisive victories by the ferocious application of concentrated military force against a weak, sensitive point.* This was true. But Jomini believed he had discovered in Napoleon’s campaigns a unique “scientific” method of conducting war in all cases, and he implied that anyone who mastered it could follow it to victory.

His conclusion was simplistic in the extreme. For how Napoleon managed to concentrate his force, and where he found the weak point to strike were the keys to his generalship. Napoleon knew that at any specific juncture he might employ any of several maxims. But the first might bring little advantage, the second stalemate, the third defeat, and only the fourth victory.

Napoleon was a supreme military artist. He understood not only which rule best suited a given situation, and but also how it should be carried out, and was acutely aware that the manner in which he implemented the rule would spell the difference between success and failure. Like Michelangelo, who saw the finished form of David hidden within a block of raw marble, Napoleon saw in the terrain, lines of supply, locations of troops, roads, weather, situation of the opposing general, and other factors before him the finished shape of a campaign or battle and how it could be decided.

Like Napoleon, a great captain is one who understands the changes under way that are affecting how war is conducted. This has not been a common accomplishment of military leaders. Over the ages commanders have most often failed to perceive the transformations of war, and both soldiers and civilians have suffered greatly because of their blindness. If the French nobility had heeded the devastating killing power of the English longbow at Crécy in 1346, they would not have fought a hundred years war. If commanders in the American Civil War had recognized the range of the Minié-ball rifle and the defensive power of field fortifications, 600,000 men would not have died in battles that were among the bloodiest in history. If generals in World War I had calculated the effects of the terrible trinity of machine gun, quick-firing artillery, and fortifications, they would not have destroyed nearly a whole generation of European youth. There is every reason to believe, however, that a profound new understanding of the challenges the world faces from terrorism has in fact been brought about by the ghastly attacks of September 11.

Whatever form warfare takes in the future, it will involve the application of strategy and tactics, the twin divisions of warfare that have existed from the start. The word strategy is taken from the Greek word for general, strategos. It is primarily the art of the general and refers most appropriately to the plan behind a whole campaign or war. Tactics refers to the methods for winning victories on the battlefield or in close combat. While the specifics of strategy and tactics are, of course, crucial to the outcome of any war, it is the underlying rules of war that are the fundamental keys to victory.

Strategy and tactics must be designed to take advantage of the wisdom embodied in the rules. No one rule is always applicable in any given situation; rather the rules offer guidelines for finding solutions in whatever circumstance a commander finds himself. The commander must evaluate every new situation with great care, and then choose the rule or rules he must employ to achieve success. The rules of war relate to solving specific problems as they arise and are not general rules always to be applied in all situations. In fact, applying a rule in the wrong situation can lead to disaster.

Since warfare has always had the same purpose---to force an opponent to do something against his will---most if not all the rules or methods by which this force can be achieved were worked out in conflicts fought before the dawn of history. Ancient pictorial records that have survived show clashes and military organizations. For example, the first fully formed phalanx, or massed body of spear-carrying infantry, appears on the Sumerian “Stele of Vultures”, which dates from the third millennium B.C. In addition, storytellers transmitted by voice the traditions of the past and recounted tales of ancient wars.

After the alphabet was invented in the west and logographic writing in China, much of this received wisdom was put down in writing.7 Magnificent examples are the Greek bard Homer’s Iliad and Odyssey, which preserved stories told by ancient Greeks before they learned to write. Thereafter, writers composed histories and narratives which described events and wars in their own times, and which drew on the accumulated wisdom inherited from the past.

These authors---some of the most famous are the Greeks Herodotus, Thucydides, and Xenophon---gave insights into the rules of war. But only one ancient writer, the great Chinese strategist Sun Tzu, produced an orderly, coherent, comprehensive summary or analysis of the rules. Sun Tzu probably inherited most if not all of his ideas from the past, but his own interpretation of them, written or assembled around 400 B.C., constitutes the most profound, succinct, and systematic treatise ever produced on the prosecution of successful war.

Sun Tzu believed careful planning and accurate information about the enemy are the keys to victory, while a commander’s primary target is the mind of the opposing general. All war, Sun Tzu said, is based on deception. The successful general must conceal his dispositions and intent. He feigns incapacity. When near he makes it appear he is far away, when far away that he is near. The general approaches his objective indirectly. Make an uproar in the east, but attack in the west. The general seeks a quick victory, not lengthy campaigns. Extended operations exhaust the treasury and the troops. The commander attacks only when the situation assures him victory. By threatening in many directions, he seeks to disperse the enemy to defend everywhere. If defending everywhere, the enemy is weak everywhere. When the enemy prepares to defend in many places, Sun Tzu said, “those I have to fight in any one place will be few.” The way to avoid what is strong is to strike what is weak. As water seeks the easiest path to the sea, so armies should avoid obstacles and seek avenues of least resistance.

Sun Tzu postulated two forces---the zheng element, which fixes the enemy in place, and the qi element, which flanks or encircles the enemy, either actually or psychologically. The zheng (ordinary) element is direct, more obvious, the qi (extraordinary) indirect, unexpected, distracting, or unorthodox. Using both elements ensures that decisive blows will fall where the enemy does not anticipate them, and is least prepared. However, the two forces are fluid. As factors change, the zheng effort can be transformed into the qi and the qi into the zheng.

Napoleon never drew up a theory of war, but his campaigns reveal six principal admonitions: rely on the offensive; pursue a defeated enemy; trust in speed to economize on time; bring about strategic surprise; concentrate superior force on the battlefield, especially at the decisive point of attack; and until the time of attack, protect forces by a “well-reasoned and circumspect” defense.8

As warfare moves into a period of revolutionary change, these rules will remain as relevant as they have always been. Some will likely be less useful, due to technological innovations, though perhaps enterprising commanders will find ways to bring them into the twenty-first century. As the essential thirteen rules of war are introduced, this book will attempt to highlight which of the rules are likely to be most effective in waging the new war and provide glimpses of the way in which the rules might be applied.

Bevin Alexander

* In this book Napoleon Bonaparte is called Bonaparte in references up to December 2, 1804, when he placed the emperor’s crown on his own head, and as Napoleon thereafter.

1. (In the notes in this book, single names refer to authors whose volumes are cited in full in the Selected Bibliography. Other sources are given in full in the notes. Numbers refer to pages.) The terrorists who attacked on September 11, 2001, were part of an organized crime syndicate or criminal insurrection group. The hatred they directed against the United States was irrational. In 1998 Osama bin Laden and fellow members of his World Islamic Front for Jihad Against the Jews and Crusaders, issued a bizarre declaration against the United States for its “occupation” of the holy land of Arabia, its “aggression” against Iraq, and its support of “the petty state of the Jews.” The declaration concluded: “To kill Americans and their allies, both civil and military, is an individual duty of every Muslim who is able, in any country, where this is possible, until the Aqsa Mosque” (in Jerusalem) “and the Haram Mosque” (in Mecca) “are freed from their grip and until their armies, shattered and broken-winged, depart from all the lands of Islam.” See The Economist, October 6-12, 2001, 19, and “The Trap,” by Hendrik Hertzberg and David Remnick in New Yorker magazine, October 1, 2001, 37-39. See also Bergen, 18-23, for a summary of an April 1997 CNN interview with Osama bin Laden by Peter Arnett and Peter Bergen which contained a number of similar complaints against the United States.

2 Clausewitz, 119, 406.

3 No responsible leader of a state will ever use nuclear weapons, because their employment would invite counterstrikes that would destroy his own people. But a terrorist group like Al Qaeda almost certainly would use a nuclear device if it could acquire one. This is the great danger the world now faces. Graham Allison, assistant secretary of defense in the first Clinton administration, wrote in the November 3, 2001, issue of TheEconomist magazine that a primary objective of the United States must be to get at the source of the greatest danger today---the nearly 100 percent of the world’s nuclear, biological, and chemical weapons of mass destruction stored in the U.S. and Russia. “The surest way to prevent nuclear assaults on Russia, America, and the world is to prevent terrorists from gaining control of these weapons or materials to make them,” he wrote. The aim would be to make all nuclear weapons and material as secure as technically possible as fast as possible. Recommendations for such controls were presented in January 2001 by a task force chaired by Howard Baker and Lloyd Cutler (

4 China, although a great power, has never fielded an army with anything approaching the high technology of the United States or the Soviet Union. Its strength has always been its enormous potential manpower and its highly sophisticated tactical or small-unit operations. These strengths are most effective in defensive operations, and Communist China has never entertained aggressive ideas beyond the historic territory of China, including Taiwan and Tibet. Its intervention in the Korean War 1950-1953 was to prevent an American or an American-assisted Chinese Nationalist incursion into mainland China.

5 The killings so soured American opinion that, after forcing the Somalis to release a wounded American pilot they had captured, the United States pulled out of Somalia. On July 20, 1950, American forces were able to approach undetected within a few yards of several North Korean T-34 tanks in the closely built streets of Taejon, Korea, and destroy them with new 3.5-inch “super bazooka” rocket launchers. See Alexander, Korea, 92-107.

6 I’m indebted to my former editor, Jonathan Slonim, for this brilliant suggestion. It is a much clearer method than the traditional chronological approach.

7 For a fascinating analysis of the development of the alphabet and writing, see Burke and Ornstein, 36-87. Although the characters of Chinese writing are often identified as pictographic or ideographic, they are actually logographic, or a system using symbols representing entire words. Characters only represent a specific word of the Chinese language. As examples, the character for “to love” depicts a woman and child, while the character for “peace” consists of the elements for roof, heart, and wine cup. See Sino-Tibetan languages, Encyclopedia Britannica, 15th edition, vol. 16, 804.

8 Fuller, The Conduct of War 1789-1961, 50-51.

<< More on 'How Wars Are Won' << Back to top