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 over the last 15 years. 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?


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.