By Erin Miller and Gary LaFree
Social movements using terrorism or terrorism driving social movements?
The relationship between social movements and terrorism has emerged as an important analytical dimension of our research on terrorist activity. Our approach to this issue has been largely inductive rather than deductive, and stems directly from our work on the Global Terrorism Database (GTD). The GTD includes data on nearly 100,000 terrorist attacks that occurred worldwide between 1970 and 2010, including when, where, and how they happened, as well as information on the perpetrators of the attack. Rather than questioning whether or not social movements use terrorism as tactic, we frequently find ourselves focused on how we can and should organize the information we have on perpetrators of terrorism in a way that accounts for the complex relationships between various groups, organizations, and individuals that share political, social, economic, or religious goals. In essence, this indicates to us that empirically terrorism is in fact a tool of social movements aimed at achieving a common goal. To illustrate this, we discuss the methodological and substantive implications of studying perpetrators of terrorism.
Who are the perpetrators?
Although the GTD is comprised of structured event-level data, given its comprehensive scope spanning four decades the database is well suited for studying long-term patterns of activity among perpetrators of terrorism. From a practical standpoint, this requires including systematically recorded names of perpetrator entities for all attacks where this information is available. As terrorism is frequently a collective action, the relevant variable in the GTD is perpetrator group name and the database accommodates up to three entries in this field for each attack. Given that GTD collection is based on unclassified sources, primarily media articles and newswires, the coding rules do not require that a perpetrator or perpetrator group be legally responsible for the attack, whether through apprehension by authorities, arrest, charge, or conviction. Rather, we record the information on perpetrators as it is reported in the source documents. Despite, or perhaps because of, this fairly low threshold of accountability, attributing responsibility for a terrorist attack to a particular group can be fairly complicated.
There are a number of possible scenarios. For just over 40% of all attacks in the GTD there is no perpetrator information available. Although perpetrators of terrorism frequently seek attention for their actions, there are times when it is not in their best interest to do so. Or, the attack may have been the work of unaffiliated and unidentified individuals. For an additional 10% of attacks, the information on perpetrators is limited to a generic group, such as Protestant Extremists or Left-wing Militants. The GTD includes 675 such generic attributions, some of which identify the perpetrator’s ideology, ethnicity, or geographic origin, and others of which do not (e.g. “Gunmen”). Finally, for just under half of all attacks, the GTD lists a specific perpetrator organization, such as the Irish Republican Army (IRA) or the Shining Path (SL). In some cases this means a particular group or groups claimed responsibility for the attack. In other cases the source reports the views of authorities or witnesses regarding who carried out the attack. Ironically, the highest profile, highest impact attacks can sometimes be particularly difficult to accurately attribute to a particular perpetrator organization using available media sources. Such events tend to be candidates for dubious claims of responsibility, and law enforcement efforts typically focus on apprehending responsible individuals, who may have unclear links to formal organizations.
With respect to the organizations themselves, over 2200 unique names of terrorist organizations appear in the GTD. Their size, structure, and age vary considerably, with the majority of named organizations carrying out attacks for less than one year. In fact, many of the perpetrator organizations in the GTD are responsible for only a few terrorist attacks. This is one of the first indications that perpetrator group dynamics and evolution can be extremely complicated. Our efforts to maintain consistent naming practices for the organizations identified in the GTD revealed numerous instances of organizations splintering into new groups, developing factions, forming alliances and hostilities with other groups, sharing members, relocating, changing leadership, and changing names. In fact, complexities like these are the norm rather than the exception. These dynamics are particularly relevant to our research on patterns of activity among terrorist perpetrator organizations, as it can often be difficult to pinpoint where one organization ends and another begins. Despite this, clear patterns emerge from the perpetrator data allowing us to identify clusters of perpetrator entities, both generic and non-generic groups that share common goals. We conceive of these clusters as movements and recognize that understanding patterns of terrorist activity among them is as important as understanding patterns of terrorist activity among individual organizations, if not more so.
Terrorist Movements
To capture this higher level of abstraction using the data in the GTD, we reviewed all perpetrator entity names in the context of the location of the attacks they carried out. This, along with supplemental research on the groups, organizations, and causes, allowed us to cluster together those that share common objectives, even if they do not agree on leadership or tactics, or if they have evolved over time, or simply developed independently. This work on the data is still ongoing, however our preliminary efforts identified 60 movements responsible for over 36,000 terrorist attacks between 1970 and 2007, or 44% of all attacks during this time period. These movements are born of various causes including particular political ideals such as the leftist movements in several countries in Latin America, Europe, and South Asia, and nationalist-separatist movements such as Irish Republicans and Loyalists, as well as Palestinian, Tamil, and Basque separatists. Some, like the Salafi-jihadist groups, are based on religious beliefs, while others represent “single issues” like animal rights and environmentalism. A typical movement in the GTD is comprised of a mixture of organizations of all sizes and structures as well as generic groupings that are identified as perpetrators. Consider, for example, the components of the Tamil separatist movement as identified in the GTD:
- Liberation Tigers of Tamil Eelam (LTTE)
- People’s Liberation Organization of Tamil Eelam
- Eelam People’s Revolutionary Liberation Front (EPRLF)
- Tamil Eelam Liberation Organization (TELO)
- Revolutionary Eelam Organization (EROS)
- Tamil Liberation Army
- Tamil Nadu Liberation Army
- Tamils
The Tamil movement includes the well-known Liberation Tigers of Tamil Eelam (LTTE), as well as a number of Tamil organizations that are less active, and the generic attribution “Tamils” whose attacks are not associated with a particular organization. By grouping the terrorist activity of these entities we are able to link together patterns of attacks and fully evaluate the life cycles of broader movements. This has critical implications for analysis of organizational dynamics and evaluations of counter-terrorism policies that require information on the emergence or demise of terrorist groups.
One piece of the puzzle
It is important to recognize that the perspective described here, which is based on information about terrorist activity in particular, fails to indicate the extent to which terrorism is just one of many tools used by social movements in an attempt to achieve their goals. A comprehensive evaluation would naturally include consideration of all tactics adopted by social movements. However the Global Terrorism Database provides a clear empirical basis for the premise that terrorism is fundamentally an instrument of social movements.
Mobilizing Ideas 