of the potential indicators of terrorist activity so that future attempts may also be thwarted.
The fact that the New York City Subway system is a focus of both international and domestic terrorists is not overly surprising given the reality of its monumental size and complex nature.
Operating twenty-four hours a day with more than 1.6 billion passengers every year, the New York Subway system is also the fourth busiest public rail system in the world, just behind Tokyo, Moscow, and Seoul (New York 1). The busiest public rail system in the Western Hemisphere also represents an ideal target for both international and domestic terrorists. The potential for terrorist attack on public rail systems garnered international attention and alarm in March 1995. At that time in Tokyo, Japan, terrorist agents, representing the religious group Aum Shinrikyo, released the deadly poison nerve gas sarin into Tokyo's massive and heavily utilized underground subway system (Pangi 421). The Tokyo attack represented the first major terrorist attacks using Weapons of Mass Destruction (WMDs) that were biochemical in nature, highlighting the potential for massive human and economic costs from their use to the Japanese and U.S. officials and others around the world.
The Tokyo attacks generated mass confusion as unprepared officials were faced with chaos and panic as hundreds of thousands fled for their lives, many seriously ill. Ultimately more than 5,500 people were injured in the attacks that also killed nineteen (Pangi 421). From crisis and consequence management to preparedness at home, the Aum Shinrikyo attacks had significant implications for the U.S. As with Tokyo officials in the wake of the sarin attacks, the U.S. no longer felt invulnerable to terrorist attacks at home.
Many changes in U.S. counterterrorism occurred after the successful Tokyo subway attacks. The Tokyo sarin attacks resulted "in a ...