Why Insurgents Attack Americans: What the Data Tells Us and What to do About it

The United States has deployed its largest concentration of warships to the Middle East in decades. American forces are engaged in an active air campaign against Iran, facing retaliatory strikes from Iranian-backed militias across Iraq and the Gulf, while sustaining counterterrorism operations in Somalia. The operational questions — where Americans are most at risk, and from whom — dominate the daily threat picture. But a prior question deserves more attention than it has received: What drives insurgent groups with primarily local agendas to target Americans, and what do they gain from it? The new book, Killing Americans: Insurgent Motivations, Risk Factors, and Implications (Oxford University Press, 2026), by Christopher Linebarger, Amira Jadoon, Suzanne Weedon Levy, and Victor Asal, offers answers, drawn from a decade of empirical data on 140 insurgent organizations, that challenge several core assumptions shaping U.S. counterterrorism strategy.

Drawing on a multi-method design that combines statistical analysis of 140 insurgent organizations with four in-depth case studies (the Revolutionary Armed Forces of Colombia, the Tehrik-i-Taliban Pakistan, Al-Shabaab, and the Islamic Movement of Uzbekistan), the book offers a comprehensive framework for understanding both the causes and consequences of anti-American insurgent violence.

The book’s central contribution is twofold. First, it provides a theoretically grounded taxonomy of motivations. Direct factors provide clear incentives for anti-American attacks — religious ideology, U.S. troop presence, and U.S. military aid to insurgent adversaries. Indirect factors create an environment conducive to such attacks or underpin a group’s capacity to undertake them — organizational alliances, rivalries, and broader economic relationships. Second, the book demonstrates that anti-American violence yields measurable strategic returns for insurgent organizations, enhancing both their lethality and their survival prospects — a finding with significant implications for counterterrorism policy.