Terrorist Strategies and Tactics: When Do Terrorists Decide to Attack the US?

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Project Details


For this project, investigators analyzed the beliefs, strategies, and circumstances of groups that have attacked the United States to discover the incentives and opportunities that led them to select American targets, using both comparative case studies and statistical analyses of event data. The research team also analyzed why some groups stopped attacking American targets although they maintained the capacity to do so. Additionally, the team employed comparative analyses to explore why groups operating in the same context with similar ideological objectives choose different strategies, some targeting the United States and others not. Investigators tested the proposition that terrorism against the United States is rooted in local conflicts.

Primary Findings:

In global terms, groups that attack the US are a minority of all terrorist groups. The project identified approximately 10% of foreign terrorist organizations active since 1968 as having targeted the US and its interests, based on the official views of the US government. (Note: this list is distinct from the official Foreign Terrorist Organization designation list.) Tracking the activities of these anti-American groups through START's GTD revealed that most of their terrorist attacks were against local targets at home, supporting the argument that the concerns and motivations of even the most anti-American groups were primarily local, as well as the proposition that terrorist groups typically stage attacks in familiar settings. Proximity is usually important. The 9/11 attacks thus stand out even more prominently as an exception to a general pattern. The project traced anti-American terrorism in a set of geographical conflict theatres and discovered that similar organizations operating in the same geopolitical context behave differently in terms of targeting the US. This finding means that explanations of anti-American terrorism based on background conditions (such as poverty, lack of democracy, or government alliances with the US) or even specific US policies or actions are less useful than explanations based on the changing goals, capacities, and strategies of particular groups. Group rationales for attacking the US are also mixed; there is unlikely to be a single objective. These comparisons also revealed that over time religious or Islamist groups have not necessarily been more likely to attack the US than secular groups (for example, in the Palestinian conflict arena, secular nationalist and leftist organizations attacked the US in the past, while Hamas does not). The project also noted that some groups continued to be active and retained the capability to attack but stopped targeting the US, such as Hezbollah. The policy implication is that a universal policy toward terrorism is unlikely to be effective because such organizations vary considerably, even within the same country, region, or conflict theatre.


This study employed mixed methods: Qualitative methods including historical surveys, case studies, focused comparisons, and process tracing. Quantitative methods included trajectory analysis (with Gary LaFree and Sue-Ming Yang). New event and group data collection was also conducted for this effort.


Project Period: