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Concept: Jihad


Terrorists can strike twice-first, by directly killing people, and second, through dangerous behaviors induced by fear in people’s minds. Previous research identified a substantial increase in U.S. traffic fatalities subsequent to the September 11 terrorist attacks, which were accounted for as due to a substitution of driving for flying, induced by fear of dread risks. Here, we show that this increase in fatalities varied widely by region, a fact that was best explained by regional variations in increased driving. Two factors, in turn, explained these variations in increased driving. The weaker factor was proximity to New York City, where stress reactions to the attacks were previously shown to be greatest. The stronger factor was driving opportunity, which was operationalized both as number of highway miles and as number of car registrations per inhabitant. Thus, terrorists' second strike exploited both fear of dread risks and, paradoxically, an environmental structure conducive to generating increased driving, which ultimately increased fatalities.

Concepts: New York City, Terrorism, September 11 attacks, September 11, Federal Bureau of Investigation, World Trade Center, Aircraft hijacking, Jihad


Large numbers of young people have joined jihadists groups in the Syrian/Iraqi conflict. Why would these young people decide to become jihadist fighters? What are the representations of the West they hold and how do these representations shape their decision? Drawing on the psychotherapeutic work with Syrian and Iraqi asylum seekers, this paper seeks to explain the most intimate reasons of young Muslim would-be fighters to join the Islamic State militias.

Concepts: Australia, Native Americans in the United States, Islam, Iraq War, Arabic language, Jihad, Utah, National Guard of the United States


This article uses a game-theoretic approach to analyze the risk of cross-milieu terrorist collaboration-the possibility that, despite marked ideological differences, extremist groups from very different milieus might align to a degree where operational collaboration against Western societies becomes possible. Based upon theoretical insights drawn from a variety of literatures, a bargaining model is constructed that reflects the various benefits and costs for terrorists' collaboration across ideological milieus. Analyzed in both sequential and simultaneous decision-making contexts and through numerical simulations, the model confirms several theoretical arguments. The most important of these is that although likely to be quite rare, successful collaboration across terrorist milieus is indeed feasible in certain circumstances. The model also highlights several structural elements that might play a larger role than previously recognized in the collaboration decision, including that the prospect of nonmaterial gains (amplification of terror and reputational boost) plays at least as important a role in the decision to collaborate as potential increased capabilities does. Numerical simulation further suggests that prospects for successful collaboration over most scenarios (including operational) increase when a large, effective Islamist terrorist organization initiates collaboration with a smaller right-wing group, as compared with the other scenarios considered. Although the small number of historical cases precludes robust statistical validation, the simulation results are supported by existing empirical evidence of collaboration between Islamists and right- or left-wing extremists. The game-theoretic approach, therefore, provides guidance regarding the circumstances under which such an unholy alliance of violent actors is likely to succeed.

Concepts: Left-wing politics, Decision theory, Political spectrum, Terrorism, French Revolution, Hamas, Jihad, Islamism


This article presents a case study on the radicalization of Omar al-Hammami, aka Abu Mansoor al-Amriki, an American who joined al-Shabaab, a Somali terrorist group. There are a limited number of in-depth case studies that help to inform the fragmented discussions in the literature about the radicalization process of Islamic terrorists. Hammami received quite a bit of attention from the government and media due to his “homegrown” status, as well as his prolific use of social media to inform the world of his views and exploits. Hammami did not fully commit to the group, his sense of self-importance taking precedent over the norms of the group. He left al-Shabaab, was publicly critical of the group, and was ultimately killed by them. Copyright © 2014 John Wiley & Sons, Ltd.

Concepts: Sociology, Case study, Cultural studies, Terrorism, Jihad, Islamic terrorism


Victory in modern intergroup conflict derives from complex factors, including weaponry, economic resources, tactical outcomes, and leadership. We hypothesize that the mind summarizes such factors into simple metaphorical representations of physical size and strength, concrete dimensions that have determined the outcome of combat throughout both ontogenetic and phylogenetic experience. This model predicts that in the aftermath of tactical victories (e.g., killing an enemy leader), members of defeated groups will be conceptualized as less physically formidable. Conversely, reminders that groups possess effective leadership should lead their members to be envisioned as more physically formidable. Consonant with these predictions, in both an opportunistic study conducted immediately after Osama bin Laden’s death was announced (Study 1) and a follow-up experiment conducted approximately a year later (Study 2), Americans for whom the killing was salient estimated a purported Islamic terrorist to be physically smaller/weaker. In Studies 3 and 4, primes of victorious terrorist leaders led to inflated estimates of terrorists' physical attributes. These findings elucidate how the mind represents contemporary military power, and may help to explain how even largely symbolic victories can influence reasoning about campaigns of coalitional aggression.

Concepts: September 11 attacks, Jihad, Special Activities Division, Al-Qaeda, Taliban, Osama bin Laden, Islamic terrorism, Videos of Osama bin Laden