A large body of recent work seeking to explain the strategies and causes of terrorism exists, with hypotheses ranging from frustration-aggression theories to strategic choice to psychological dysfunction or a number of other factors. Remarkably few studies examine the actual sources of terrorism, however. Despite the existence of some large databases that categorize terrorist incidents, such as the MIPT (Memorial Institute for the Prevention of Terrorism) Dataset, few published works analyze the correlation between terrorism and types of movements (nationalist, religious, anarchist, Marxist, environmentalist, etc.) and the number or scale of terrorist attacks. This research provides a simple, clear, evidence-based and relative measure of which kinds of groups resort to terrorism. Although databases such as that of MIPT suffer from a large number of terrorist incidents carried out by unknown perpetrators, as well as classification problems (groups can typically be both religious and nationalist, for instance), the evidence examined here indicates that nationalist groups and Islamist movements, in that order, were the most common kinds of non-state actors that resorted to terrorism between 1998 and 2007. Islamist groups do, however, appear responsible for more fatalities than any other kind of terrorist during this period. We conclude by offering tentative applications of these correlations to some of the most prevalent theoretical explanations for terrorism. We do this in only a preliminary sense, in order to see how a better notion of the actual ‘correlates of terrorism” might affect thinking and policymaking on the issue.


Political Science

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© 2019 The Author(s). This open access article is distributed under a Creative Commons Attribution (CC-BY) 4.0 license.


insurgency, peace and conflict studies, political violence, security studies, terrorism

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Cogent Social Sciences