Ground transportationNew insights into terrorist threats to ground transportation

Published 13 April 2012

A new analysis of terrorist attacks, and attempted attacks, on ground transportation shows that from the late 1980s to the mid-1990s, terrorist groups used chemicals to attack surface transportation; from the mid-1990s on, multiple bombs became the new prototype for terrorist attacks

The Mineta Transportation Institute has released its newest research report, Carnage Interrupted: An Analysis of Fifteen Terrorist Plots Against Public Surface Transportation, which examines several factors in thirteen plots that authorities uncovered and foiled before attacks could be carried out. It also presents two additional cases in which terrorists attempted to carry out attacks that failed. Principal investigators were Brian Michael Jenkins and Joseph Trella.

We can learn much from terrorists’ failures,” said Jenkins, “because they provide insights into terrorist ambitions, clues to possible new directions in tactics and weapons, and details about how the plots evolve. These details often are more difficult to discern when an attack has succeeded and its perpetrators are dead or have fled.”

The reports analyze plots in the West from 1997 to 2012, primarily in the United States and the United Kingdom because they have been frequent targets. These incidents have involved publicized arrests and trials, which provide additional information.

Among others, the fifteen plots include:

  • 1997 – Flatbush Plot (New York)
  • 2002 – Poison Gas on London Underground Plot
  • 2004 – Herald Square Bomb Plot (New York)
  • 2005 – Melbourne and Sydney Terrorist Plots
  • 2006 – Milan Metro Bomb Plot
  • 2006 – Attempted German Train Bombings (Cologne)
  • 2008 – Barcelona Metro Bomb Plot
  • 2009 – Zazi Bomb Plot (New York)
  • 2010 – Washington Metro Bomb Plot (Washington, DC)

Jenkins explains that these plots were part of an ongoing global campaign of terrorism directed against a variety of targets in Western nations. The campaign was inspired by continuing exhortations from al Qaeda and waged by individuals or small groups determined to be part of the global armed struggle.

The report describes each plot in terms of the terrorists’ plan, their motivation, objective, target selection, tactics and weapons, reconnaissance, timing, security measures in place at the target, and how the plot was disrupted.

Jenkins said, “Terrorists tend to imitate what’s been done before, so they will try to replicate attacks — including targets, tactics, and techniques — that they see as successful. It is not possible to identify the source of inspiration or instruction for all of the 15 cases, but some spectacular precedents are likely to have inspired these plots. For example, four of the plots involved chemical or biological substances — poison gas or ricin. It seems highly likely that the plotters in these cases had in mind the 1995 sarin attack in Tokyo, where terrorists dispersed nerve gas in subways, killing 12 and sending over 5,000 to hospitals. Further inspiration and instruction came from al Qaeda’s own interest in chemical and biological weapons.”

Jenkins further noted that none of these exotic plots succeeded. Indeed few progressed beyond the talking stage, and it seems doubtful that any would have resulted in mass casualties.

By mid-decade the poison fad was over,” he said. “Meanwhile, terrorists in Madrid and London demonstrated that by using more reliable explosive devices on trains and subways, terrorists could achieve the slaughter they desired. Multiple bombs became the new prototype for terrorist attacks, a pattern that continued through the end of the decade.”