The Power to Resist: Mobilization and the Logic of Terrorist Attacks in Civil War

• Author: Sara M. T. Polo,Belén González
• Published date: 01 November 2020
• Date: 01 November 2020
• DOI: http://doi.org/10.1177/0010414020912264
• Subject Matter: Articles

https://doi.org/10.1177/0010414020912264

Comparative Political Studies

2020, Vol. 53(13) 2029 –2060

© The Author(s) 2020

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DOI: 10.1177/0010414020912264

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Article

The Power to Resist:

Mobilization and the

Logic of Terrorist

Attacks in Civil War

Sara M. T. Polo1 and Belén González2,3

Abstract

Existing research has argued that terrorism is common in civil war because

it is “effective.” Surprisingly, however, only some groups use terrorism

during civil wars, while many refrain altogether. We also see considerable

variation in the use of terrorism over time. This article presents a theory of

terrorism as a mobilization strategy in civil war, taking into account benefits,

costs, and temporal dynamics. We argue that the choice and the timing

of terrorism arise from the interaction between conditions for effective

mobilization and battlefield dynamics. Terrorism can mobilize support when

it provokes indiscriminate government repression or when it radicalizes

rebels’ constituency by antagonizing specific societal groups. The timing of

attacks, however, is influenced by battlefield losses, which increase rebels’

need to rally civilian support. The analyses of new disaggregated data on

rebels’ terrorist attacks during conflicts (1989–2009) and of Islamic State of

Iraq and Syria (ISIS) tactics in Iraq and Syria support our theoretical argument.

Keywords

civil war, rebel groups, terrorism, mobilization, conflict dynamics

1University of Essex, Colchester, UK

2Leuphana University Lüneburg, Germany

3GIGA German Institute of Global and Area Studies, Hamburg, Germany

Corresponding Author:

Sara M. T. Polo, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK.

Email: sara.polo@essex.ac.uk

912264CPSXXX10.1177/0010414020912264Comparative Political StudiesPolo and González

research-article2020

2030 Comparative Political Studies 53(13)

Introduction

In 2017, 10 organizations alone were responsible for 4,282 terrorist attacks,

amounting to approximately 40% of all attacks and 68% of all terrorist fatali-

ties in that year (17,915 victims).1 Nine of these organizations have been

involved in civil wars, which have now become the main source of global

terrorism (Findley & Young, 2012). Many have argued that groups in conflict

use terrorism because it “works” (e.g., Kydd & Walter, 2006; Pape, 2003).

For example, terrorism may increase groups’ chances of entering into nego-

tiations and obtaining government concessions, and help to advertise the

group’s cause to a large audience (e.g., Thomas, 2014; Wood & Kathman,

2014). However, a closer look at insurgent groups’ actual use of terrorism in

civil conflicts2 reveals two surprising patterns. Although some groups carry

out a large number of attacks, nearly 50% of all insurgent groups active

between 1970 and 2011 never resorted to terrorism. Moreover, among groups

that employ terrorism, there is considerable temporal variation in its use.

Figure 1 illustrates this variation for a sample of groups engaged in civil war

during the past 8 years. It is clear that terror tactics are not used regularly,

with attacks being concentrated at specific times and almost absent at others.

Given the existing arguments about terrorism’s effectiveness, it is puzzling

that terrorism is not used more often and by all rebel groups. Why, then, do

some rebel groups resort to terror tactics, while others refrain from doing so?

And what explains the timing of terrorist attacks in civil war?

Despite a growing body of work on terrorism in civil war, the existing

research only provides incomplete answers to these questions. Studies have

pointed to several factors associated with terrorism such as regime type,

rebel capabilities, funding sources, ideology, intergroup competition, and

organizational structures (e.g., Belgioioso, 2018; Fortna et al., 2018;

Hultman, 2007; Polo & Gleditsch, 2016; Stanton, 2013). Although impor-

tant, these factors tend to be rather static and cannot explain variation in the

use and frequency of terrorism by rebel groups over time. To date, the timing

of terrorism in civil war remains largely unexplained. Moreover, many exist-

ing studies tend to emphasize the benefits of terrorism while downplaying

its costs, especially the risk that terrorism will backfire by alienating civil-

ians (see also Fortna, 2015). Most rebel groups rely on some form of local

civilian support (Kalyvas, 2006). As a result, it remains unclear why, and

when, groups that depend on popular support can benefit from resorting to

terror tactics.

In this article, we present a theory of terrorism as a mobilization strategy

in civil war. This theory aims to explain not only why some rebel groups

resort to terrorism (and many others refrain from doing so) but also when

they do so—that is, the timing of terrorist attacks. Drawing on a rationalist

Polo and González 2031

framework, we regard terrorism as a tool to help rebels achieve proximate

rather than ultimate goals. Winning the support of the local population is a

key proximate goal for rebel organizations. We argue that rebel groups

seeking to drum up popular support employ terrorism as an instrument of

mobilization. Building on seminal research by Lake (2002), Kydd and

Walter (2006), and Goodwin (2006), we identify the logics of provocation

and boundary activation as key mechanisms of mobilization. Rebel groups

use terrorist attacks to provoke indiscriminate government repression and

to radicalize their core constituency by exacerbating in-group out-group

cleavages. These mechanisms, however, are not straightforward and are

fraught with risks. Terrorism may generate selective government responses

that can be lethal for rebels (Carter, 2016) and entail significant political

costs, such as the alienation of civilians. We explicitly incorporate such

risks and identify two conditions under which terrorism is more likely to be

effective in mobilizing civilians. When rebel groups fight a government

that is susceptible to provocation due to a history of indiscriminately repres-

sive policies, groups can leverage government responses to overcome col-

lective action problems and mobilize fence-sitters against the incumbent.

Terrorism is also beneficial when there is a strong out-group antagonism

within rebels’ core constituency. Insurgents can then exploit provocative

attacks against out-groups to radicalize their support-base and reduce the

risk of abandonment or backlash.

Figure 1. Patterns of terrorism by rebel groups over time.