Terrorism and Irregular Warfare

The CSIS Warfare, Irregular Threats, and Terrorism Program collaborates with the International Security Program, Middle East Program, Africa Program, and more to provide analysis on irregular and hybrid warfare, terrorist violence, and military operations. 

Photo: AUDU MARTE/AFP/Getty Images

Photo: AUDU MARTE/AFP/Getty Images

Why Did the United States Conduct Strikes in Nigeria?

Isolated strikes like the ones carried out by the United States are unlikely to significantly reduce the terrorist threat in the region or reverse Nigeria’s growing insecurity.

Critical Questions by Alexander Palmer and Erin Oppel — December 26, 2025

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Daniel Byman

Daniel Byman

Director, Warfare, Irregular Threats, and Terrorism Program
Seth G. Jones

Seth G. Jones

President, Defense and Security Department; Harold Brown Chair
Jon Alterman

Jon B. Alterman

Zbigniew Brzezinski Chair in Global Security and Geostrategy

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Why Did the United States Conduct Strikes in Nigeria?

Isolated strikes like the ones carried out by the United States are unlikely to significantly reduce the terrorist threat in the region or reverse Nigeria’s growing insecurity.

Critical Questions by Alexander Palmer and Erin Oppel — December 26, 2025

Questions to Ask After a Terrorist Attack

Confusion reigns after a terrorist attack. Initial reporting is often flawed, and misperceptions endure even after being debunked by experts. Asking the right questions can help policymakers, journalists, and the public distinguish signal from noise, avoid costly overreaction, and prepare for future threats.

Commentary by Daniel Byman — December 16, 2025

Ideological Trends in U.S. Terrorism

The Warfare, Irregular Threats, and Terrorism Program examines the state of terrorism in the U.S., finding left-wing violence has risen in the last decade but from very low levels and still well below historic levels of violence by right-wing and jihadist actors.

Analysis by Daniel Byman and Riley McCabe — September 26, 2025

Will, Cohesion, Resilience, and the Wars of the Future

In both Ukraine and Israel, the story of resilience is not only about battlefield endurance but also the mobilization of society—military, civilian, technological, and psychological—to resist aggression and maintain national cohesion.

Commentary by Daniel Byman — September 16, 2025

How NATO Can Support the United States in Asia

NATO members can, and should, play an important role in the event of a crisis over Taiwan, in the Philippines, or other confrontations with China.

Commentary by Iselin Brady and Daniel Byman — June 23, 2025

Aid Cuts Make Peace Negotiations in Ukraine Less Likely

Cutting U.S. aid to Ukraine now would not hasten peace. It would encourage the Kremlin to believe what it has long hoped for—that U.S. resolve is fleeting, and that time is on Russia’s side.

Commentary by Riley McCabe — June 16, 2025