In Depth

Terrorism in America After 9/11

A comprehensive, up-to-date source of online information about terrorist activity in the United States and by Americans overseas since 9/11
Photo: © Yang Lei/Xinhua/Alamy Live News

This In-Depth report from our International Security Program examines broad trends in the jihadist terrorist threat facing the United States that have emerged since the 9/11 attacks. We provide an overview of the terrorism in cases we've tracked since 9/11, and we examine three key questions: Who are the terrorists targeting the United States? Why do they engage in terrorism in the first place? And what threat do they pose?

The data in this report consists of individuals accused of jihadist terrorism related crimes since 9/11 who are either American citizens or who engaged in jihadist activity within the United States. The data also include a small number of individuals who died before being charged but were widely reported to have engaged in jihadist criminal activity, We define jihadists to include those who are motivated by versions of bin Laden's global ideology or otherwise provide support to groups that follow a version of that ideology. We exclude cases linked to Hamas, Hezbollah, and similar groups that do not follow bin Laden's ideology and do not target the United States.


Part I. Terrorism Cases: 2001-Today

Terrorist-related cases are on the rise in the United States, especially since the onset of the Syrian civil war.

Part II. Who are the Terrorists?

Conventional wisdom holds that the jihadist threat is composed of foreigners or young, male hot-heads. The truth is more complicated.

Part III. Why do they Engage in Terrorism?

The motivations of jihadist extremists in America are difficult to disentangle, and easy explanations are often proven wrong.

Part IV. What is the Threat to the United States Today?

Most U.S. attacks are carried out by individuals inspired by jihadism, but with no direct involvement from abroad.