Reducing threats is a major challenge for both governments and citizens.
What the World’s Terrorist Groups Have in Common
Strong ideology motivates those who commit terrorism, no matter their goals.
Who Counts As a Terrorist?
From foreign groups to domestic threats, how does the U.S. government define terrorism?
Terrorism by the Numbers
What the numbers behind terrorism—and the process of getting to them—reveal.
263 government organizations
were created or reorganized following 9/11.
Source: Washington Post
U.S. Counterterrorism Since 1945
The history of counterterrorism in the United States is more than a list of policies. It shows how the definition of terrorism and the agencies and tools used to pursue those who commit it have evolved over time.
of the public says that the ability of terrorists to launch another major attack on the United States is greater than it was at the time of the 9/11 attacks.
Source: Pew Research Center
Tools of Counterterrorism
National security experts have a range of options available as they work to prevent terrorism.
Identity and Radicalization
What are the ways in which people—overwhelmingly young people—become radicalized?
How a Single Phrase Defined the War on Terror
The open-ended scope of the 2001 Authorization for Use of Military Force has justified counterterrorism policy for two decades—and counting.
The Terrorist Money Trail
What the challenges of targeting terrorists’ finances tell us about the evolving terrorist threat.
Terrorism Module Assessment
Questions to check your understanding.
Terrorism Reading List
Supplemental readings and other resources.
How Terrorism Affects You
Source: Khaled Abdullah/Reuters
This is Your Brain on Terrorism
Although terrorism kills very few Americans, constant coverage makes us perceive a widespread threat.
Source: Sara K. Schwittek/Reuters
How a Decade of Terror Changed America
Reflect on the profound changes to American policy, society, and collective understanding of war in the years following 9/11.
More From CFR
From Tragedy to Prevention: Lessons Learned From Terrorist Attacks
Photo: Darren Staples/Reuters
Women Are Critical to Counterterrorism
Photo: Christopher Herwig/Reuters