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resham bahadur nepali sarki
Sep 19, 2025, 10:43 AM
Islamist terrorism saw a significant rise following the September 11, 2001, attacks, led primarily by al-Qaeda, ISIS, and their affiliates. More recently, we have seen an upsurge in right-wing political extremism in countries around the world. The question of whether there are systematic differences in the use of violence between political ideologies remains unanswered, despite the expanding body of research that these developments have produced. We address these gaps by comparing the use of political violence by left-wing, right-wing, and Islamist extremists in the United States and worldwide using two unique datasets. We find that left-wing causes are associated with less violent individuals and attacks in both datasets. In the worldwide dataset specifically, we find that compared to other ideologies, Islamist extremists engage in deadlier attacks.
Abstract
It is unclear whether there are systematic differences between ideologies in the use of violence to pursue a political cause, despite the fact that political violence has been committed on behalf of a wide range of political ideologies. Prior research on this topic is scarce and mostly restricted to self-reported measures or less extreme forms of political aggression. Moreover, it has generally focused on respondents in Western countries and has been limited to either comparisons of the supporters of left-wing and right-wing causes or examinations of only Islamist extremism. Using two distinct datasets that cover real-world examples of politically motivated, violent behaviors, we compare the use of political violence by left-wing, right-wing, and Islamist extremists worldwide and in the United States to fill in these gaps. Across both datasets, we find that radical acts perpetrated by individuals associated with left-wing causes are less likely to be violent. In the United States, we find no difference between the level of violence perpetrated by right-wing and Islamist extremists. However, differences in violence emerge on the global level, with Islamist extremists being more likely than right-wing extremists to engage in more violent acts.
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Historically speaking, political violence has been perpetrated on behalf of a wide range of political ideologies (1, 2). This could suggest that the willingness to use violence for a cause is independent of the ideological content and can be expected across the ideological spectrum given sufficiently high levels of conflict. At the same time, individuals espousing different ideological views have been found to differ with regard to personality profiles (3), cognitive functioning (4), social motives (5), values (6), and moral beliefs (7). Given that these factors may predispose individuals to aggression, one might expect similar differences between ideologies with regard to the use of political violence. However, despite the growing interest in research on political ideology (8), very few studies have directly examined patterns of violent behavior across the ideological spectrum. In this research we address this gap by comparing the use of political violence by left-wing, right-wing, and Islamist extremists in the United States and worldwide using two unique datasets that cover real-world examples of politically motivated, violent behaviors.
Left-Wing versus Right-Wing Extremism
Of these three ideologies, most prior research has contrasted those committed to right-wing and left-wing causes. Much of this research suggests that compared to left-wing extremists, right-wing extremists may be more likely to engage in politically motivated violence. In comparison to left-wing supporters, right-wing individuals are more often characterized by closed-mindedness and dogmatism (9) and a heightened need for order, structure, and cognitive closure (5). Because such characteristics have been found to increase in-group bias and lead to greater out-group hostility (10), violence for a cause may be more likely among proponents of right-wing ideologies. Left-wingers, on the other hand, score higher on openness to new experiences, cognitive complexity, and uncertainty tolerance than right-wingers do. They are also less likely to support social dominance (11), which could lead to their overall lower likelihood to use violence against adversaries. In line with this reasoning, some studies have demonstrated an empathy gap between liberal and conservative individuals (12). Finally, according to various conceptualizations and operationalizations of right-wing authoritarianism (RWA; 13–15), aggressive tendencies constitute an inherent component of this construct, with people high in RWA being more hostile toward others who violate norms than those low in RWA. A recent meta-analysis supported this conclusion, revealing a positive relationship between right-wing ideology and aggressive attitudes and behaviors (16). However, the study only included milder forms of aggression and did not concentrate solely on politically charged settings. Moreover, not all prior studies have supported the idea of ideological asymmetry. For instance, one study (17) found no difference between liberals and conservatives in the empathy they felt toward their political opponents. Further, although aggression is indeed included in classic conceptualizations of RWA, there have been suggestions that RWA is not necessarily a unidimensional construct and that relations between its subdimensions and social outcomes may be more complex (18). Thus, it is unclear to what extent right-wing authoritarians support or engage in nonnormative violence such as terrorism. At the same time, recent work on left-wing authoritarianism suggests that left-wing beliefs could also be related to support for aggression when aggressive acts are aimed at social hierarchy (19).
More generally, there is growing evidence suggesting that extremists representing different ideologies may have more in common than has been assumed (20). For example, extreme liberals and conservatives both represent the social world in a similar, simplistic way, which distinguishes both groups from more moderate individuals (21). In studies of behavior in conflict, one study (22) found that both right-wing and left-wing extremists used more negative and angrier language than moderates did. Finally, a strong inclination to defend one’s beliefs against worldview-violating groups and a low tolerance for such groups has been identified for both liberals and conservatives (23). This research suggests that both right-wing and left-wing extremists may use violence to achieve their ideological goals in equal measure. To put it succinctly, the findings regarding differences in ideological groups' propensity to resort to political violence are inconsistent and largely indirect. Another important limitation comes from the fact that these studies have investigated predominantly mainstream samples and, in most cases, relied on attitudinal measures of aggressive tendencies. Research that compares perpetrators of real-world acts of political violence on behalf of different ideological causes is rare. It is thus unclear to what extent the current literature on political ideology generalizes to such extreme cases. Finally, extant research that does examine differences between right-wing and left-wing individuals has been limited mostly to Western samples and has generally omitted other ideological groups such as those representing Islamist extremism.
Islamist versus Right and Left-Wing Extremism
While there are examples of religious terrorism from a number of denominations, in recent years Islamist terrorism has far and away received the most research and policy attention (24, 25). It has been singled out in particular for its deadly attacks on government and military facilities as well as its promotion of martyrdom through suicide attacks (26, 27). Moreover, while religiously charged motives for terrorist attacks were common in the past, a unique feature of their most recent form is that the religious aspect of the movement has become the dominant one (28–30). Some researchers (31–33) consider this to be one of the main reasons for the increasing lethality of terrorism in the past two decades.
There have been few empirical tests of the claim that religiously motivated terrorism is more deadly than other forms of terrorism. One of the rare studies that investigated this claim showed that Islamist terrorist organizations had significantly higher casualty rates than other types of terrorist organizations, controlling for a wide variety of rival explanations (34). However, this study also found that when affiliation with the al-Qaeda network was controlled for, Islamist groups were only slightly more likely than non-Islamist groups to commit high casualty terrorist attacks. While useful, this study was limited to 7 years, excluded domestic attacks, and was completed before the meteoric rise of several major Islamist groups since 2005, including ISIS, Boko Haram, and al-Shabaab.
According to previous theories, Islamist extremists may be more like right-wing extremists than left-wing extremists in their willingness to use violence. Islamist extremism seems to share with far-right extremism such key traits as fundamentalism, closed-mindedness, authoritarianism, and dogmatism (32, 35). In line with this reasoning, one study (35) referred to Islamist extremists as “devoted actors” and noted the rigidity and closed-mindedness of adherents. Another study (36) concluded that Muslim countries are markedly more authoritarian than non-Muslim countries, even controlling for a range of potentially influential factors. However, despite the fact that it is theoretically conceivable, there is no direct evidence to test the hypothesis that Islamist and other ideological groups use violence in similar ways. Overview of the Cu
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