A consortium of researchers dedicated to improving the understanding of the human causes and consequences of terrorism

START Assesses Impact of 9/11


START Assesses Impact of 9/11

September 6, 2011

As the 10th anniversary of the September 11, 2001, terrorist attacks approaches, START is releasing a background report that explores the unique nature of the 9/11 attacks and examines terrorism trends pre- and post-2001.

Key findings from the report include:

  • More people died in the 9/11 attacks than in all other US terrorist attacks from 1970 to 2010.
  • The 9/11 attacks involved the first terrorist hijackings in the United States since 1984. There has not been a successful terrorist hijacking in the United States since 9/11.
  • Prior to 9/11, al-Qa'ida had successfully launched only three other terrorist attacks globally?having attacked the US embassies in Kenya and Tanzania in 1998 and the USS Cole in the Port of Aden in Yemen in 2000. Since 9/11, groups allied with al-Qa'ida are responsible for over 12,000 deaths worldwide. Globally, over 65,000 people have died in terrorist attacks since 2001, with an average of 7258 deaths in terrorist attacks per year.
  • From 1991-2000, the United States averaged 41.3 terrorist attacks per year. After 2001, the average number of US attacks decreased to 16 per year from 2002-2010.
  • From 2003-2007, there were no fatalities from terrorist activity in the United States.

The full background report is available here