Reducing threats is a major challenge for both governments and citizens.
Understanding Terrorism Throughout History
Learn how scholars classify terrorist groups.
Who Gets Designated a Terrorist and Why
In the United States, policy often plays a role in deciding who gets labeled a terrorist.
Terrorism by the Numbers
What does data reveal about terrorist attacks around the world?
263 government organizations
were created or reorganized following 9/11.
Source: Washington Post
U.S. Counterterrorism: Evolution Over The Past Century
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 Terrorism
The open-ended scope of the 2001 Authorization for Use of Military Force has served to justify two decades of counterterrorism policy and counting.
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