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Backgrounder: Targets for Terrorism: Ground Transportation

Council on Foreign Relations

Author: cfr.org editorial staff
Updated: July 13, 2006

Could terrorists attack ground transportation in the United States?

Yes. Since September 11, U.S. authorities have issued several general warnings of possible terrorist attacks on parts of the ground transportation system, including subways, railroad trains, and bridges. Unlike airlines, where security checkpoints screen passengers and luggage, mass transit options like subways, passenger trains, and buses, are designed to be easily accessible and are therefore harder to protect. Ground transportation systems—which often include enclosed spaces packed with people—could prove tempting targets for terrorists.

How might terrorists attack ground transportation?

Experts say the most likely sort of attack on U.S. subways or buses would involve setting off conventional bombs; the materials and know-how are readily available. Nor do experts rule out the sort of suicide bombings that have targeted Israeli buses. Less likely but far more devastating scenarios involve the release of a chemical agent such as sarin gas or a biological agent such as anthrax or smallpox into a subway system. Terrorists could also derail a passenger train or blow up a bridge or tunnel, killing many people and crippling a city’s infrastructure for months or even years.

Have terrorists ever targeted ground transportation outside America?

Yes, often. The most recent include the March 2004 al-Qaeda bombing of rush hour trains in Madrid, killing 191 people, the July 2005 London tube bombings (three subways and one bus were bombed), which killed fifty-two people, and the July 2006 attacks on Mumbai's commuter rail that killed more than 200.

Terrorists abroad have used guns and conventional bombs to kill and injure civilians in subways, trains, and buses for decades. Palestinian suicide bombers have repeatedly blown up buses in Israel, and the Irish Republican Army (IRA) repeatedly attacked the London Underground and British passenger trains.

Read the rest of this article on the cfr.org website.

Copyright 2006 by the Council on Foreign Relations. This material is republished on GlobalSecurity.org with specific permission from the cfr.org. Reprint and republication queries for this article should be directed to cfr.org.