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.

Direct factors provide clear incentives for anti-American attacks, often related to the ideological foundations of insurgent groups or the overt involvement of the United States in their home countries. The book identifies several empirically significant drivers. U.S. troop presence in a conflict-afflicted country is associated with a significantly higher probability that local insurgent groups will target American citizens. U.S. military aid to the government opposing the insurgency is another strong predictor, as insurgents perceive such assistance as the United States directly supporting their adversary. Religious ideology, particularly Salafi-Jihadist frameworks, provides both a moral rationale and operational mandate for targeting Americans. Notably, the study finds that the only insurgent groups to successfully carry out attacks on Americans outside their home state were those motivated by religious ideology.

Indirect motivations refer to cases in which insurgents attack Americans not because of specific American actions, but because of the organizational benefits such attacks confer. In competitive insurgent environments featuring multiple rival groups, attacking Americans can function as an outbidding strategy—signaling operational capability to potential recruits and sympathizers and differentiating one group from its competitors. Alliance networks and inter-group rivalries both amplify this dynamic.

Conversely, the book identifies a mitigating factor: American soft power, operationalized through trade relationships and the presence of American cultural markers, is associated with a reduced likelihood of anti-American attacks. The authors argue that economic interdependence and cultural familiarity may dampen both insurgent motivation and local tolerance for anti-American violence.

Perhaps the book’s most consequential finding concerns what happens to insurgent groups after they attack Americans. The data analysis demonstrates that insurgent organizations that target Americans exhibit increased lethality in subsequent operations and greater organizational longevity. Throughout the entire study period and across the 140 organizations analyzed, only one organization—Indonesia’s Free Aceh Movement (GAM)—ceased operations after engaging in anti-American attacks.

The proposed mechanism is that successfully striking at a superpower signals operational sophistication to multiple audiences simultaneously. Such attacks attract recruits, draw resources from sympathizers, and solidify alliances. Anti-American violence, in this framing, functions as a strategic investment that yields tangible organizational returns. This finding complicates conventional deterrence logic, which assumes that the threat of American retaliation would dissuade insurgent groups from such targeting. The evidence suggests that for many organizations, the reputational and material benefits of attacking Americans outweigh the associated risks.

The book's empirical findings yield several direct implications for U.S. foreign policy and counterterrorism strategy, as discussed below.

Intervention generates targeting incentives — minimize visible footprints. One of the book's most robust findings is that American military intervention, including troop deployments, military aid, and foreign assistance, is positively correlated with increased attacks on Americans, both within conflict zones and transnationally. The instruments designed to stabilize conflict-affected regions simultaneously generate new targeting incentives for insurgent groups. This suggests that deployment decisions should account for this empirically documented cost. Where possible, intervention strategies should shift toward intelligence sharing, specialized training for local security forces, and economic assistance channeled through multilateral institutions.

Deterrence alone is insufficient — invest in prevention. The data challenge the assumption that the threat of U.S. retaliation will deter insurgent groups from targeting Americans. Groups that attack Americans tend to grow more capable and more resilient. The organizational benefits enhanced recruitment, increased funding, strengthened alliances appear to outweigh the risks of retaliation for a significant number of groups. If retaliation does not weaken the attacking organization, and may in fact strengthen it, then a policy response that focuses on prevention, mitigating the conditions that make anti-American violence an attractive organizational strategy in the first place, is important to consider. 

Soft power has measurable protective effects — treat it as force protection. Countries with strong trade relationships with the United States and a visible American cultural presence experience fewer anti-American attacks. Economic interdependence and cultural familiarity appear to reduce both insurgent motivation and community tolerance for anti-American violence. Cultural exchange programs, educational initiatives, and trade agreements that visibly benefit local economies should be understood not as peripheral programming but as cost-effective complements to security-focused approaches.

Deployments require public diplomacy. Military deployments unaccompanied by public diplomacy create an information vacuum that insurgent propaganda can exploit. Any deployment should be accompanied by robust communication strategies explaining the purpose and scope of U.S. presence to local populations.

Prioritize groups that have attacked Americans. Because anti-American attacks enhance group survival and lethality, groups conducting their first attack on Americans should trigger rapid-response protocols. This could include enhanced intelligence collection, targeted sanctions, and coordinated international disruption, before the organizational benefits compound.

Adopt organizationally informed threat assessment. Ideology and grievance alone do not explain anti-American violence. Groups with territorial control, extensive alliance networks, and operational sophistication are significantly more likely to target Americans. Territorial control provides staging infrastructure; alliances provide resources, expertise, and broader reach. Threat assessment should incorporate these organizational variables into tiered threat assessment models rather than relying on ideological indicators alone.

Fragmented battle spaces elevate risk. In environments featuring multiple rival insurgent groups, attacking Americans can serve as an outbidding mechanism, allowing groups to distinguish themselves from competitors. The collapse of central authority in a given country can paradoxically increase anti-American targeting incentives. Fragmented conflict environments warrant particular attention in threat assessments.

Transnational ideologies enable targeting beyond borders. Within the study period, only religiously motivated groups carried out transnational attacks on Americans. However, the authors caution that this finding is temporally bounded. Transnational ideological waves are cyclical — left-wing internationalism dominated the mid-twentieth century, Salafi-Jihadism shaped the early twenty-first, and right-wing extremism may represent an emerging trajectory. The structural dynamic — that all-encompassing transnational ideologies enable targeting beyond one's home territory — may persist across ideological iterations.

Prepare for multipolar targeting dynamics. As great power competition intensifies and other states provide military support to client governments in conflict zones, the dynamics the book describes will increasingly apply beyond the United States. Collaborative intelligence-sharing with allies facing comparable insurgent threats becomes a growing strategic necessity.

These findings do not counsel withdrawal or inaction. They counsel precision, in calibrating military footprints, in pairing deployments with public diplomacy, and in treating economic engagement as force protection rather than peripheral programming. As great power competition draws additional states into military interventions across conflict-affected regions, the dynamics this book identifies will increasingly apply beyond the United States. The framework offers a lens for the threat environment practitioners face today.

This article draws on the findings of Killing Americans: Insurgent Motivations, Risk Factors, and Implications by Christopher Linebarger, Amira Jadoon, Suzanne Weedon Levy, and Victor Asal (Oxford University Press, 2026). Dr. Amira Jadoon is a co-author of the book and the founding editor of The Durand Dispatch.