Distinctive Characteristics of Terrorist Groups


Project Details


This project, headed by START director Gary LaFree and Maryland criminologist Laura Dugan, develops additional data on terrorist groups to supplement the GTD and the Minorities at Risk projects. These additional data improve understanding of group-level terrorist processes. This project focuses on four research areas:

  • Group-based trajectory analysis
  • Role of religion in terrorist strikes
  • Relationship between state failure and terrorism
  • Using gang research to inform terrorism studies
Primary Findings:

The main focus of this project has been on developing a better understanding of terrorist organizations and their distinctive characteristics. This project has supported five main research efforts.

  • First, we examined the 25 most active terrorist organizations in the world and whether they operated in failed states from 1970 to 1997. Three of these organizations were operating in states that were classified as failed for 20 or more of the years included; 15 of the organizations were in countries classified as failed for 10 or more years; and only 8 groups were operating in countries that were never classified as failed states.
  • Second, in a related analysis, we examined the attack patterns for the most active organizations in the most active country (or territory) for each region from 1970 to 1997. For some locations, such as Northern Ireland, the overall trend matches the attack pattern for one organization (the IRA). For others, such as South Africa, the overall attack pattern is driven by attacks not attributed to any organization. In general, the analysis demonstrates which movements drove attacks over time for each nation.
  • Third, we also compared the 20 most active organizations to the 20 most active that used some form of weapons with WMD potential. While some names are represented in both lists (e.g., Hezbollah, FARC, Hamas, Al-Qaida, and the Khmer Rouge), others, like the Dishmish Regiment and Mujahidin-e-Khalq, have thus far committed relatively few attacks and generated a small number of fatalities.
  • Fourth, we also compared the activity of two Armenian terrorist organizations to try and explain their rise and fall. Findings suggest that ASALA attacks dropped after an especially brutal bombing alienated their primary constituency.
  • Finally, results from a semi-parametric group-based trajectory analysis reveal that the most lethal organizations are the ones that are persistent but attack less frequently.

At the beginning of this study the primary source for the Global Terrorism Database (GTD), Pinkerton Global Intelligence Services (PGIS), was a closet full of index cards that listed details on each incident, sometimes including the name of a group. Because there were many different persons collecting this information, the notations used to signify the same groups varied dramatically. The original electronic version of the PGIS recorded over 5,000 terrorist organizations. After spending two years comparing the names and attack patterns of the terrorist organizations, and validating them against outside sources, the GTD now lists around 1,500 unique terrorist organizations. We have also used outside sources to link the most active organizations to their primary base of operations, as well as identification of the primary ideologies of the organizations. Statistical methods include descriptive analyses, semi-parametric group-based trajectory analysis, and series-hazard modelling.


Project Period: