How Terrorism Works

­Nailing down an exact definition for "terrorism" is tricky business. The Merriam-Webster dictionary defines it as "the systematic use of terror, especially as a means of coercion." Of course, humans can find terror in just about anything -- some people are deathly afraid of birds or even cats. But the most palpable fear is that of death, and the will to avoid it is hardwired into our genes. Terrorism leverages the threat of imminent death to achieve a goal.

Fear of death also plays a major role in warfare. Soldiers throughout history have labored to appear more terrifying -- from dabbing on face paint to draping their horses in the bloody scalps of their adversaries. When two armies meet on the battlefield, the contest ultimately depends on fighting prowess, weapon technology and strategy. But if one army eventually breaks and flees, aren't the soldiers running to escape death? Likewise, if a soldier sticks to the front lines to avoid summary execution for desertion, then aren't his heroics fueled by the same fear?

To avoid such semantic complications, most modern definitions of terrorism emphasize the deliberate targeting of civilians. This is different from the incidental targeting of civilians, such as blowing up a school during the aerial bombardment of a nation's capitol. With terrorism, the school would be the primary target. Yet, even attacks against military targets, such as the 2000 bombing of the USS Cole, have been labeled terrorist acts.

Limiting terrorism to violence against civilians hardly lets professional military off the hook. History is filled with examples of armies deliberately targeting regular people. When armies laid siege to walled cities, they leveled the prospect of starvation and disease against the inhabitants. And when the siege broke, massacre, rape and enslavement often followed -- and the 21st century is hardly free of such atrocities.

­In 2006, the United Nations reported that the systematic rape of civilians was a prominent feature of conflicts in Bosnia-Hergovina, the Democratic Republic of the Congo, East Timor, Haiti and Darfur [source: BBC News]. Darfur, a region of Sudan, has become a prominent modern example of violence against civilians in wartime, with thousands enslaved and hundreds of thousands killed or forced to flee their homes [source: BBC News].

War and violence against civilians are inseparable. To exclude the atrocities committed by soldiers, some politicians and historians limit the definition of terrorism to the actions of groups that aren't officially affiliated with a state. Under this definition, civilian organizations are capable of terrorism, while a police force isn't -- even if both perpetrate the same heinous acts.

­Yet, as we'll learn in the next section, the word "terrorism" has its origins not in the acts of civilians, but in the often bloody relationship between a government and its citizens.

­Targeting civilians with violence may be as old as war, and war may be as old as humanity itself, but our use of the word "terrorism" only dates back to the 1790s. France's new revolutionary government had just taken control of a country rife with rebellion and civil war. The "enemies of the Revolution" were plentiful and, on Sept. 5, 1793, the government enacted a decree to deal with them. Mass arrests were made and soon suspects' rights to trial and legal aid vanished as well. The Committee of Public Safety wielded the powers of acquittal and death. This period became known as the Reign of Terror, and before its end on July 27, 1894, an estimated 17,000 men and women were sent to the guillotine.

The goal of terrorism is never to simply control the immediate recipients of the violence, but to reach a wider audience by creating an atmosphere of fear and anxiety. With tyrannical governments, the message of so-called establishment terrorism is usually "obey or else."

Maintaining rule of law is one of the basic tenets of government, and the ultimate deterrent to unlawful behavior is almost always violence [source: Davidson]. If you fail to pay your taxes, for instance, enough inaction on your part will inevitably lead to law enforcement officers showing up at your door to take you away. When all the bureaucratic avenues have been spent, law comes down to force. The difference between a free society and one living under terror can be seen as a matter of degree. How soon does physical violence materialize in a nation's enforcement of law? How often does a government exercise its power to kill and disenfranchise?

The French certainly didn't invent the use of state-controlled violence on domestic enemies. History books contain plenty of examples of totalitarian terror campaigns, from the Nazis and Stalinists of the 20th century to the ancient Romans and beyond. As long as there have been governments to rebel against, there have been violent attempts to repress the rebels. Military dictatorships often prove useful examples of this.

Augusto Pinochet's rule in Chile, for example, was marked by the repression of leftist politics. Allegations of human rights violations emerged over time, including accusations that the regime kidnapped and murdered leftist citizens. From 1973 to 1980, Chile joined with several other South American nations to form "Operation Condor," an intelligence-sharing effort to crack down on insurgents and, yes, ­terrorists.

­If estab­lishment terrorism follows a top-down model, then revolutionary terrorism is the bottom-up version (though it's sometimes sponsored by foreign states). The two models often share a codependent relationship, with a repressive government using terror to combat terrorist forces, each fanning the other's fires. For instance, the Roman Empire and the rebellious Jewish Sicarii waged wars of terror against each other during the first century A.D. over occupied Judea.

Just as establishment terrorism often arises when more lenient forms of keeping law and order fail, so too does revolutionary terrorism become an option when a military victory isn't possible. Rebellion can take different forms. On one extreme, you can field an army against a dominant government if you have the resources. If you're outmatched, however, other methods are available.

­If you can't defeat a superior force on the battlefield, you can chip away at it through guerilla warfare until its forced to yield. This has led many social scientists to refer to such tactics as the "weapon of the weak." Yet while guerilla warfare may entail violence against civilians, it isn't generally defined by it. This leads us back to the more specific definition of terrorism as the systematic use of violence against civilians, in this case by noncombatants, to generate a climate of fear to bring about change. In these cases, victory is often impossible, even by attrition. The cause becomes less about achieving an objective (such as political change) as it is about publicizing the cause and gaining reprisals against real or perceived wrongs. In these cases, terrorism becomes a violent revenge drama to attract attention and spread a message through fear.

­Another form of terrorism is subrevolutionary terrorism, in which the terrorists fight to change existing political or social structures, but without deposing a regime. For instance, the African National Congress was classified by the United States as a terrorist organization for its sometimes-violent efforts in the 1980s to end South African apartheid. In the post-Civil War American South, the Ku Klux Klan brutally lynched blacks to push a white supremacist agenda. Both groups attempted to change public and social policy, rather than overthrow the government.

­No universal definition for terrorism exists, but as we've explored, a handful of adjectives allow us to better understand how it fits into human society. We've discussed establishment terrorism, revolutionary terrorism and subrevolutionary terrorism. These terms refer to the goals of terrorism and the architects of terror themselves. But if we think of terrorism as a product, the scope and location of the consumers also plays a major role in understanding it.

Terrorism can be separated into domestic and international categories. The former involves terrorists acting within the borders of their own country, such as the 1995 Oklahoma City bombings in the United States and the Tokyo subway nerve gas attacks perpetrated by Japanese cult Aum Shinrikyo. In international terrorism, however, the organizers export terror to another country. This brand of terrorism gained a great deal of attention following the Sept. 11 attacks in the United States. The suicide terrorists involved in the attack were linked to al-Qaida, an international terrorist group with operations in various countries.

Another important distinction to make is that between retail and wholesale terrorism. In business terms, retail involves selling small quantities to the ultimate consumer. A small store might have three toasters in stock, with the intention of selling individual toasters to individual customers. Wholesale, on the other hand, involves selling large quantities, generally to a wholesaler -- such as a chain of home appliance stores. Re­tail ­terrorism involves the small-scale use of terror to achieve its goals, while wholesale terrorism deals in massive, indiscriminate death. For example, hijacking an airplane is retail terrorism, but intentionally crashing it into a major population center is wholesale terrorism.

The difference between the two often comes down to the tools of the trade.

­Weapon and communications technology have changed the face of warfare, so it shouldn't come as a surprise that terrorism has benefited as well. In fact, it has evolved -- growing from retail terrorist attacks against individuals and small groups to wholesale terrorist attacks that endanger thousands of lives.

In the past, terrorists often depended on the assassination of key individuals or the use of hostage situations. There is, after all, only so much one person can achieve with daggers and bows. Large-scale death was generally the specialty of armies and, as such, most of history's atrocities were carried out by governments and militaries. Gunpowder would change all this, empowering the individual to inflict unprecedented destruction. After all, how much can you fear one man in an age of daggers and clubs as opposed to the age of suicide bombers and lone gunmen?

Explosives made such activities as the Guy Fawkes' 1605 Gunpowder Plot against the British Parliament a reality. The 2002 Beltway sniper attacks in the United States demonstrated how two men with a rifle could terrify millions. In 2004, a group of Chechen rebels stormed a school in the Russian town of Beslan, taking more than a thousand hostages. They ultimately killed 334 of them, including 186 children.

Sometimes the weapons of wholesale terrorism aren't even weapons, but repurposed technology. The destruction of the World Trade Center showed us that a commercial airliner can become a missile. The only real weapons used in the attack were a handful of box cutters, no different in function than Stone Age artifacts.

With the right explosives, biological or chemical agent, terrorists can target densely populated areas and potentially kill thousands. Technology has also added organizational strength to terrorist efforts. E-mail and cellular communication make it po­ssible for terrorists to organize efforts from the other side of the globe, as well as recruit new personnel. Modern banking also makes it possible for terrorist organizations to receive funding from international benefactors and distribute it surreptitiously wherever money helps further their ends.

Terror is wielded by the mighty and by the weak, but how does a nation fight terrorism without becoming terrorists themselves? How do a people oppose a tyrannical government without drowning in as much blood as the tyrant? Human societies continue to strive for answers to these ­questions. Some argue for identifying and treating the root causes of many forms of terrorism, such as the frustration and aggression associated with disenfranchisement. Others argue that it should be treated purely as a criminal or military threat. For establishment terrorism, the arguments range from nonviolent protest to bloody revolution or military intervention by foreign powers.

A definitive answer to terrorism, however, remains as elusive as a definitive definition of the term itself.

Explore the links on the next page to learn even more about terrorism.