Bombings were the most prevalent form of attack against transportation in 1998, occurring 45 percent of the time, against virtually every mode of transportation. In addition, 25 bomb threats in which transportation was diverted or seriously disrupted were reported. Armed attacks were most prevalent against highways, and in the maritime arena during acts of piracy. Hijacking, kidnapping, and sabotage incidents increased 47 percent from a year ago, in all areas except commercial aviation. Hijacking of commercial airliners has decreased substantially over the last decade, while the hijackings of private aircraft, buses, commercial vehicles, and ships are on the rise.
A wide variety of weapons, some having the capability to inflict massive damage and large numbers of casualties, are potentially available to terrorist groups to carry out attacks. Bombs and small arms historically have been the most common means of attack, mainly because they are easy to acquire and to use. We believe bombs will remain the primary weapons of choice in the near-term. Based on analysis of worldwide violence against transportation systems, the greatest threat is likely to stem from a bombing intended to cause mass casualties. While some experts believe the likelihood is growing that terrorists will attempt a chemical or biological attack within the next few years, bombs and bullets, which are inexpensive, easily available, familiar, and which can be extremely destructive, will remain the terrorists' weapons of choice.
Chemical/Biological Weapons. Nearly five years ago the apocalyptic Japanese cult Aum Shinrikyo released sarin gas into the Tokyo subway system, killing a dozen people and sickening thousands. This event raised the specter of terrorists using chemical or biological weapons to murder thousands of people. Since the Tokyo incident, no similar terrorist acts of using chemical or biological (C/B) weapons to cause mass casualties have occurred. Nevertheless, the terrorists' ability to use more sophisticated weapons systems is improving and the likelihood is increasing that terrorists will try to use a C/B weapon in the next several years. Moreover, hoaxes involving biological agents are increasing exponentially. In 1998, the FBI investigated nearly 150 threats involving anthrax from among more than 245 cases involving chemical, biological, or nuclear weapons. As recently as 1996, the FBI investigated 37 such cases.
Transportation may be an attractive target for terrorists desiring to commit a C/B attack. Subways, trains, airplanes, and buses generally offer closed air systems, meaning that a C/B agent is less likely to be affected by ambient air or weather conditions. Nevertheless, there remain financial, technical, and psychological constraints to the widespread use of C/B weapons by terrorists. Developing a C/B weapon may cost many thousands or millions of dollars, while a few hundred dollars can buy sufficient materials to destroy a 20-story office building. Effective dissemination of C/B materials to produce mass casualties is yet another constraint. Despite the millions of dollars invested by the Aum in modern C/B production facilities, their crude dissemination system led to the ultimate failure of their gas attacks. Additionally, the psychological impact of a C/B attack could alienate potential supporters from the terrorist's "cause" and act as a restraint.
