It's still too soon, surely, to get our minds around Tuesday's horror. But by calling the World Trade Center and Pentagon attacks terrorism—by placing them in a category of political violence we think we know—we begin the effort to figure it out. We begin, but no more. For while this is clearly terrorism, it's also clearly terrorism of a sort we've never seen before.
Though there's no single definition of, political scientists use some criteria to distinguish it from other political violence. Unlike war, modern terrorism doesn't occur between states; it's perpetrated by stateless organizations against established powers. It ignores codes of war that most nations acknowledge. Unlike guerrilla warfare or political insurrection, it doesn't attack military or government centers with an eye toward seizing power; it targets unsuspecting victims—often random civilians—who may have nothing to do with the terrorists' grievances. It's a strategy used by small organizations to publicize their cause and sow panic among the strong. Those with a stake in society, terrorists hope, will find the fear so intolerable that despite their wealth and power they'll capitulate to the terrorists' demands.
Terrorism's roots date to ancient times. In the first century C.E., when the Romans ruled Palestine, a Jewish order called the Zealots committed random murders in busy crowds. They did so, the historian Josephus wrote, to create a "panic … more alarming than the calamity itself; everyone, as on the battlefield, hourly expected death." The Zealots wanted to silence Jewish moderates and begin an uprising against Rome. Their tactics succeeded, leading to a disastrous revolt that ended in their own mass suicide atop the mountain Masada.
Likewise, from about 1090 to 1275, a Shiite Muslim sect called the Assassins (from the Arabic for "hashish eaters") tried to purify Islam with surprise killings of their Sunni rivals. After committing their crimes, the Assassins would assent in their own capture and execution, taking pride in martyrdom. (Osama Bin Laden says he takes Hasan ibn al-Sabah, the Assassins' founder, as a hero.) In medieval Christendom too, sects waged violence against clergy and nobles in pursuing a revolution within the church.
The word "terrorism" itself comes from the French Revolution's "Reign of Terror" (1793-94), when Robespierre and his Jacobin gangs rounded up and executed some 12,000 people deemed—often for the flimsiest reasons—enemies of the Revolution. The Jacobins were running the French state, so they wouldn't be called terrorists by our current definitions. Yet their vision of a violent purge in the name of remaking society provided a model for other insurgents who would follow.
In the 19th and early 20th centuries, that Jacobin vision took hold in Russia, Europe, and the United States. Although it's often forgotten (as noted in a "History Lesson" last year) that some anarchists abjured violence and actually resembled radical communitarians, anarchy did produce its share of killers. Leon Czolgosz, who shot William McKinley in 1901; Alexander Berkman, who tried to kill steel magnate Henry Frick in 1892; the Russian anarchists who assassinated Czar Alexander II in 1881—all targeted political or industrial leaders in the name of working men or a popular revolution. These assassinations, and public bombings like the one at Chicago's Haymarket in 1898, succeeded in their short-term goals of generating publicity and inducing popular panic, though they failed in their long-term aim of launching a revolt against capitalism.
The next stage in terrorism's development came in the mid-20th century, when indigenous peoples in today's Egypt, Indonesia, Israel, Kenya, Vietnam, and elsewhere rebelled against their colonial regimes. Like their anarchist forebears, they used dramatic, vicious acts of destruction to win attention. Still, these crusades remained essentially wars of rebellion. For example, the Irgun, a Jewish revolutionary group in 1940s that Palestine sometimes labeled terrorist, bombed Jerusalem's King David Hotel not to kill haphazardly but because the hotel housed the British colonial government. The violence was ruthless but its victims hardly random.
It was a short step, however, from these insurgencies to the anti-colonial liberation movement that is credited with spawning modern terrorism: Algeria's Front de Libération Nationale, which introduced the tactic of targeting civilians on a massive scale. After France executed two Algerian rebels in 1956, the FLN slaughtered 49 Frenchmen over three days. FLN terrorists attacked such targets as beachside cafes where they knew families, including children, would perish. They sought to raise the price of continued colonialism to unbearable levels. And they succeeded.
The FLN's crusade inspired others to adopt their tactics: Basque and Quebecois separatists, Palestinian and Irish nationalists, leftist revolutionary movements in Africa and Latin America. By the 1960s, the targeting of civilians to spread fear and secure political gains was rampant, even in developed nations. The Weather Underground in the United States detonated thousands of bombs around the country in 1969 and 1970 (one of which killed three of its own members in a Greenwich Village townhouse). [Correction: Most of these bombings were the work of local militants, not the Weather Underground.] The Marxist Baader-Meinhof Gang in West Germany undertook robberies, murders, bombings, and kidnappings. The Red Brigades in Italy kidnapped business leaders and abducted and in 1978 slew former prime minister Aldo Moro.
But Western terrorism of that era (like the more recent right-wing variants of Timothy McVeigh and his ilk) paled next to the violence brewing in the developing world, especially the Middle East. It needn't cast doubt on Yasser Arafat's recent efforts to reach peace with Israel to recall that in the 1960s and 1970s he ranked among the most bloodthirsty and innovative terrorists, happy to target civilians. The PLO, of which he became chairman in 1968, pioneered hijacking and hostage-taking as ways to win global recognition. It embraced coldblooded murder and the bombing of school buses. The PLO's constituent groups perpetrated the most indelible terrorist acts of our times: The first major hijacking, of an Israeli commercial jet in 1968; the murder of 11 Israeli athletes at the Munich Olympics in 1972; the hijacking of an Israeli plane to Entebbe, Uganda, in 1976, resulting in an Israeli commando raid to liberate the hostages; the killing of the wheelchair-bound American Leon Klinghoffer amid the commandeering of the Italian cruise ship Achille Lauro. There were scores of less-well remembered hijackings, hostage-takings, and bombings, with American and Israeli victims.