A. Planning and Organization

All terrorists share one characteristic: They never commit actions randomly or senselessly. Every terrorist wants an attack to generate maximum publicity because media attention helps achieve the intimidation needed for terrorism's success. Accordingly, terrorist acts are carefully planned. Testimony by a terrorist convicted in the 1998 bombing of the U.S. embassy in Kenya revealed that al-Qaeda spent nearly five years planning the attack.

Several essential elements go into planning a major terrorist attack. Planning begins with gathering detailed reconnaissance and intelligence about a target: its defenses, vulnerabilities, and patterns of daily activity. Meanwhile, logistics specialists ensure that all the supporting tasks are accomplished. These tasks include assembling the weapons and other supplies and communications equipment needed for the operation, arranging for safe houses and transportation for the terrorist attack team, and mapping escape routes. A bombmaker or other weapons expert often joins the final planning phases. Finally, after all the preparations have been completed, the operation is handed off to the team that carries out the attack. For security reasons separate teams that do not know one another execute each step, from planning to logistics, attack, and escape.

All terrorist groups share another basic characteristic: secrecy about their operations. Terrorism operates underground, concealed from the eyes of the authorities and from potential informants among the populace. To maintain secrecy, terrorist groups are often organized into cells, with each cell separate from other cells in the organization but working in harmony with them. A terrorist cell can be as small as two or three people, with only one person knowing someone in another cell. Should the authorities apprehend a member of one cell, they can obtain information only about the activities of that cell—or at most about an adjacent cell—and not about the entire organization. For this reason terrorists prefer this organizational structure of interconnected cells. The structure narrows, in pyramid fashion, as it rises toward the group's senior command structure and leadership at the top, to whom very few have access.

B. Targets of Terrorism

Terrorism often targets innocent civilians in order to create an atmosphere of fear, intimidation, and insecurity. Some terrorists deliberately direct attacks against large numbers of ordinary citizens who simply happen to be in the wrong place at the wrong time.

More selective terrorist attacks target diplomats and diplomatic facilities such as embassies and consulates; military personnel and military bases; business executives and corporate offices; and transportation vehicles and facilities, such as airlines and airports, trains and train stations, buses and bus terminals, and subways. Terrorist attacks on buildings or other inanimate targets often serve a symbolic purpose: They are intended more to draw attention to the terrorists and their cause than to destroy property or kill and injure persons, although death and destruction nonetheless often result.

Despite variations in the number of attacks from year to year, one feature of international terrorism has remained constant: The United States has been its most popular target. Since 1968 the United States has annually led the list of countries whose citizens and property were most frequently attacked by terrorists. Several factors can account for this phenomenon, in addition to America's position as the sole remaining superpower and leader of the free world. These include the geographical scope and diversity of America's overseas business interests, the number of Americans traveling or working abroad, and the many U.S. military bases around the world.

C. Weapons of Terrorism

Bombing historically has been the most common terrorist tactic. Terrorists have often relied on bombs because they provide a dramatic, yet fairly easy and often risk-free, means of drawing attention to themselves and their cause. Few skills are required to manufacture a crude bomb, surreptitiously plant it, and then be miles away when it explodes. Bombings generally do not require the same planning, organization, and knowledge required for more sophisticated operations, such as kidnapping, assassination, and assaults against well-defended targets.

Not surprisingly, the frequency of various types of terrorist attacks decreases in direct proportion to the complexity or sophistication required. Armed attacks historically rank as the second most-common terrorist tactic, followed by more complex operations such as assassination of heads of state or other well-protected people, kidnapping, hostage taking, and hijacking.

C1 Bombs

Bombs can consist of commercially produced explosives such as black powder, TNT, or dynamite; military supplies such as plastic explosives; or commercially available materials made into homemade explosives, such as fertilizer (ammonium nitrate) mixed with diesel fuel. Bombs can be either explosive or incendiary (designed to cause a fire upon impact). The most effective bombs typically employ a shaped charge (explosive) that channels the force of the blast in a specific direction. Bombs are detonated (made to explode) by a variety of means. Time-delay detonators use a clock, wristwatch, or other timing device. Remote-control detonators rely on radio or other electronic signals. In command-wire detonation a button is pressed or a plunger pushed to trigger the explosion.

C2 Firearms

Many terrorists have favored firearms, including automatic weapons such as assault rifles, submachine guns, and pistols; revolvers; sawed-off shotguns; hunting rifles with sniper sights, especially for assassination; and machine guns. During the 1990s, terrorists increasingly used rocket-propelled grenades and other armor-piercing projectiles in their attacks. These weapons, more powerful forms of the bazookas used in World War II (1939-1945), can penetrate successive layers of ceramic and reinforced-steel that protect vehicles used by the police and military forces. Another favorite terrorist weapon is the hand grenade or its homemade equivalent, the Molotov cocktail. This crude grenade is made by filling a glass bottle with gasoline, stuffing a rag down the bottle's neck, and igniting the rag just before tossing the bottle at a target.