B.J.Pol.S. 43, 559–577 Copyright r Cambridge University Press, 2012
doi:10.1017/S0007123412000452
First published online 10 October 2012
Repression Hurts: Coercive Government Responses
and the Demise of Terrorist Campaigns
URSULA E. DAXECKER* AND MICHAEL L. HESS
The question of how coercive government policies affect the duration and outcome of terrorist
campaigns has only recently started to attract scholarly interest. This article argues that the effect of
repression on terrorist group dynamics is conditional on the country’s regime type. Repression is
expected to produce a backlash effect in democracies, subsequently lengthening the duration of terrorist
organizations and lowering the probability of outcomes favourable to the government. In authoritarian
regimes, however, coercive strategies are expected to deter groups’ engagement in terrorism, thus
reducing the lifespan of terrorist groups and increasing the likelihood of government success. These
hypotheses are examined using data on terrorist groups for the 1976–2006 period; support is found for
these conjectures on terrorist group duration and outcomes.
But then Bloody Sunday happened and again this incredible sense of outrage y And following
along Bloody Sunday I decided that what I was doing y was wanting to go home more and
more. And as soon as I came home, I got into Sinn Fein, and it was a natural progression from
there. Because my beliefs were fairly well formulated at the time. The British were killing our
people, they were locking them up, and they were nothing more than Stormont.1
INTRODUCTION
What explains why and how terrorist groups decide to end their campaigns? The factors
influencing the duration and outcomes of terrorist campaigns have only recently started to
attract the attention of terrorism researchers. This article argues that government repression
undermines terrorist groups in non-democratic regimes, but is counterproductive in
democracies because it leads to a backlash against the government and more durable
terrorist organizations. In democracies, harsh government responses harm the regime’s
legitimacy and thus reduce co-operation from local communities, increase recruitment and
support for terrorist organizations, and erode popular support for the government.
Conversely, authoritarian regimes are less constrained by legitimacy considerations in their
counter-terrorism efforts, and their repressive measures can thus reduce the lifespan of
terrorist groups in non-democratic regimes.
* Department of Political Science, University of Amsterdam (email: u.daxecker@uva.nl); Department
of Political Science, University of New Mexico. The authors would like to thank Kristian Gleditsch,
Victor Asal and three anonymous reviewers for their exceptionally helpful comments. An online appendix
for this article is available at http://dx.doi.org/10.1017/S00071234 and http://ursuladaxecker.weebly.com/
research.html. Data and supporting materials to reproduce the numerical results are available at
http://dvn.iq.harvard.edu/dvn/dv/ued.
1
A former IRA member describing his decision to join the organization, as quoted in Robert W.
White, ‘From Peaceful Protest to Guerrilla War: Micromobilization of the Provisional Irish Republican
Army’, American Journal of Sociology, 94 (1989), 1277–302, p. 1292.
The British government’s response to escalating terrorist violence in Northern
Ireland in the late 1960s, for example, was characterized by harsh repressive measures.
Interventions included internment without trial, criminalization of terrorism suspects,
coercive interrogation, curfews, extensive search operations and military deployment.2
The
adoption of repressive counter-terrorism policies increased Catholics’ distrust in the
government and resulted in a wave of recruitment for the Irish Republican Army (IRA).3
When British counter-terrorism policy gradually shifted from suppression to accommodation
in the 1980s, Catholics started to believe that reform in Northern Ireland was possible, which
opened the door for peace negotiations.4
A series of ceasefires negotiated with paramilitary
forces culminated in the Good Friday Accords in 1998.
This example illustrates our claim that coercive responses to terrorism tend to be
counterproductive in democracies. Our article contributes to terrorism research in several
ways. First, our explanation of why the effects of repression on terrorist organizations differ
between democratic and non-democratic regimes helps reconcile the contradictory findings
in existing studies. Secondly, our study evaluates the effects of repression on terrorist
campaign outcomes, including government victory, settlement, group victory and splinters.
Our findings for campaign outcomes demonstrate that repression in democracies is
counterproductive: coercion reduces the probability of negotiated settlements, but increases
the likelihood of group victory. Thirdly, our empirical analysis controls for both group- and
state-level characteristics, thus improving on earlier studies that lacked information on
terrorist groups.
The article first reviews the existing research on terrorist group duration and outcomes.
The next section develops our theoretical argument, which expects the effects of
repression on terrorist group termination and campaign outcomes to be conditional on
states’ regime type. The argument is tested using data on terrorist groups provided by
Jones and Libicki.5
The results support many of our expectations and are robust to a
number of different model specifications.
THE DURATION OF TERRORIST CAMPAIGNS
While past research has significantly increased our understanding of the formation of
terrorist groups, the dynamics of terrorist attacks and target selection, and state responses
to terrorism, scholars have only recently started to pay attention to the question of why
and how terrorist campaigns end. Case study assessments of particular groups dominated
research on the subject until a recent increase in systematic evaluations.6
One strand of
2
Gary LaFree, Laura Dugan and Raven Korte, ‘The Impact of British Counterterrorist Strategies on
Political Violence in Northern Ireland: Comparing Deterrence and Backlash Models’, Criminology, 47
(2009), 17–45; Ignacio Sanchez-Cuenca and Luis de la Calle, ‘Domestic Terrorism: The Hidden Side of
Political Violence’, Annual Review of Political Science, 12 (2009), 31–49.
3
White, ‘From Peaceful Protest to Guerrilla War’.
4
Adrian Guelke, ‘The Northern Ireland Peace Process and the War Against Terrorism: Conflicting
Conceptions?’, Government and Opposition, 42 (2007), 272–91.
5
Seth G. Jones and Martin C. Libicki, How Terrorist Groups End: Lessons for Countering Al Qa’ida
(Santa Monica: Rand Corporation, 2008).
6
Jones and Libicki, How Terrorist Groups End; S. Brock Blomberg, Rozlyn C. Engel and Reid
Sawyer, ‘On the Duration and Sustainability of Transnational Terrorist Organizations’, Journal of
Conflict Resolution, 54 (2009), 303–30; S. Brock Blomberg, Khusrav Gaibulloev and Todd Sandler,
‘Terrorist Group Survival: Ideology, Tactics, and Base of Operations,’ Public Choice, 149 (2011), 441–63;
Audrey Kurth Cronin, How Terrorism Ends: Understanding the Decline and Demise of Terrorist
560 DAXECKER AND HESS
research focuses on how the characteristics of terrorist groups are related to group
disengagement.7
Findings show that religious groups have longer durations than leftist,
right-wing or nationalist organizations.8
In addition, group strength – measured as the
size of terrorist groups – has been shown to increase the lifespan of terrorist groups.9
No
clear findings have emerged with regard to the breadth of terrorists’ goals.10
A second strand in the literature emphasizes the relevance of state characteristics and
state responses for explaining the duration of terrorist groups. Research has not produced
conclusive findings on the effect of regime type on group duration. Blomberg et al. do not
find a consistent relationship between groups operating in democratic countries and
group termination, whereas Jones and Libicki and Young and Dugan find no association
between democracy and group termination.11
With regard to repression, no research
has systematically evaluated the effect of coercive government responses on group
termination.12
Case study research on the effect of repression on individual terrorist
groups has produced contradictory findings. Studies of groups in Northern Ireland, Italy,
Germany and Israel show that the use of repressive policies backfired and exacerbated the
growth, intensity and duration of terrorist campaigns.13
However, analyses of cases in
(F’note continued)
Campaigns (Princeton: Princeton University Press, 2009); Joseph K. Young and Laura Dugan, ‘Why Do
Terrorist Groups Endure?’, paper presented at the Annual Meeting of the International Studies
Association, New Orleans, 2008. Since none of the systematic studies evaluate the outcomes of terrorist
campaigns, we can only review insights on terrorist group duration.
7
Only studies by Jones and Libicki and Blomberg, Gaibulloev and Sandler account for group-level
characteristics. Yet Jones and Libicki’s regression analysis may be biased because their empirical analysis
includes only groups that ended their campaigns within their time frame. Blomberg et al. is the only
systematic study that controls for group characteristics. Jones and Libicki, How Terrorist Groups End;
Blomberg, Gaibulloev and Sandler, ‘Terrorist Group Survival’.
8
Blomberg, Gaibulloev and Sandler, ‘Terrorist Group Survival’.
9
Jones and Libicki, How Terrorist Groups End; Blomberg, Gaibulloev and Sandler, ‘Terrorist Group
Survival’.
10
Jones and Libicki, How Terrorist Groups End.
11
Blomberg, Engel and Sawyer, ‘On the Duration and Sustainability of Transnational Terrorist
Organizations’; Jones and Libicki, How Terrorist Groups End; Young and Dugan, ‘Why Do Terrorist
Groups Endure?’.
12
None of the systematic studies discussed include variables for government repression. While not
focused on group duration, systematic research exists for the relationship between repression and terrorist
events, and repression and dissent, respectively. Research by Kurrild-Klitgaard, Justensen and
Klemmensen finds a curvilinear relationship between respect for human rights and terrorist activity.
See Peter Kurrild-Klitgaard, Mogens Justesen and Robert Klemmensen, ‘The Political Economy of
Freedom, Democracy and Transnational Terrorism’, Public Choice, 128 (2006), 289–315. Yet research by
Abrahms and Walsh and Piazza concludes that respect for human rights reduces terrorism. See Max
Abrahms, ‘Why Democracies Make Superior Counterterrorists’, Security Studies, 16 (2007), 223–53;
James I. Walsh and James A. Piazza, ‘Why Respecting Physical Integrity Rights Reduces Terrorism’,
Comparative Political Studies, 43 (2010), 551–77. Research on repression and dissent has produced mixed
findings of a negative, positive, curvilinear or no relationship. For a review, see Christian Davenport,
‘State Repression and Political Order’, Annual Review of Political Science, 10 (2007), 1–23.
13
Sanchez-Cuenca and de la Calle, ‘Domestic Terrorism’; LaFree, Dugan and Korte, ‘The Impact of
British Counterterrorist Strategies on Political Violence in Northern Ireland’; Donatella Della Porta,
‘Leaving Underground Organizations: A Sociological Analysis of the Italian Case’, in Tore Bjorgo and
John Horgan, eds, Leaving Terrorism Behind: Individual and Collective Disengagement (New York:
Routledge, 2009), pp. 66–88; Tom Parker, ‘Fighting an Antaean Enemy: How Democratic States
Unintentionally Sustain the Terrorist Movements They Oppose’, Terrorism and Political Violence, 19
(2007), 155–79.
Government Responses and Terrorist Campaigns 561
Egypt, Argentina, Uruguay and a set of Middle Eastern countries indicate that coercive
government responses can successfully terminate terrorist groups.14
Consequently,
repression seemingly exacerbates the intensity and duration of terrorist groups in some
cases, but contributes to their decline in others. The theoretical argument developed
below helps account for these contradictory findings.
REPRESSION, REGIME TYPE AND DISENGAGEMENT FROM TERRORISM
Our argument maintains that the effect of coercion on group duration and outcomes
depends on whether repressive measures alter governments’ legitimacy.15
Similar to
earlier research, we conceptualize terrorism as a competition over popular support and
legitimacy between the government and the terrorist group, but expect that the outcome
of this battle is conditional on the importance of legitimacy considerations for the regime
in power.16
Political regimes vary considerably in the extent to which they depend on the
support of the public at large. We therefore anticipate that repression leads to backlash
effects (that is, lengthens the duration of terrorist groups) in regimes that depend on the
perceived legitimacy of their actions, such as democracies. Conversely, in regimes that rely
less on popular support, such as authoritarian regimes, coercion is expected to produce
deterrence effects (that is, reduce the duration of terrorist groups).17
Repression and Terrorist Group Duration in Democracies
We expect that adopting harsh techniques in response to terrorist events results in
backlash effects in democracies. While repressive measures are intended to weaken a
terrorist group and compromise its security, such strategies likely backfire in regimes that
derive their support from the guarantee of civil rights and liberties. Since the existence of
14
Diaa Rashwan, ‘The Renunciation of Violence by Egyptian Jihadi Organizations’, in Bjorgo and
Horgan, Leaving Terrorism Behind, pp. 113–33; Howard Handelman, ‘Labor-Industrial Conflict and the
Collapse of Uruguayan Democracy’, Journal of Interamerican Studies and World Affairs, 23 (1981),
371–94; Paul H. Lewis, Authoritarian Regimes in Latin America: Dictators, Despots, and Tyrants (Oxford,
UK: Rowman & Littlefield, 2006); Abdelaziz Testas, ‘Determinants of Terrorism in the Muslim World:
An Empirical Cross-Sectional Analysis’, Terrorism and Political Violence, 16 (2004), 253–73. However,
Testas uses the incidence of terrorist attacks as the dependent variable and measures repression with data
from Freedom House, which is typically used to measure democracy.
15
We evaluate the possible implications of our argument on terrorist group activity in the robustness
test and find support for our main contention when using terrorist events as the dependent variable. We
believe that a focus on duration is more helpful, since a temporary increase or decline in attacks as a result
of repression cannot tell us whether government coercion contributed to the eventual decline of terrorist
groups.
16
For theoretical arguments, see Ethan Bueno de Mesquita and Eric S. Dickson, ‘The Propaganda of
the Deed: Terrorism, Counterterrorism, and Mobilization’, American Journal of Political Science, 51
(2007), 364–81; Andrew Kydd and Barbara F. Walter, ‘The Strategies of Terrorism’, International
Security, 31 (2006), 49–79; Peter B. Rosendorff and Todd Sandler, ‘Too Much of A Good Thing? The
Proactive Response Dilemma’, Journal of Conflict Resolution 48 (2004), 657–71, p. 658. Walsh and
Piazza’s empirical analysis finds that disregard for physical integrity rights increases the incidence of
terrorist attacks, but their study does not evaluate whether the effect of repression on terrorist events is
conditional on regime type. Yet the effect of such policies on popular support for the government seems
arguably more relevant in regimes that depend on such support. Walsh and Piazza, ‘Why Respecting
Physical Integrity Rights Reduces Terrorism’.
17
We borrow the terms backlash effects and deterrence effects from LaFree, Dugan and Korte, ‘The
Impact of British Counterterrorist Strategies on Political Violence in Northern Ireland’.
562 DAXECKER AND HESS
civil rights and liberties is widely accepted in democracies, harsh government responses to
terrorism – such as holding suspects without charging them, assassinating suspected
terrorists, curbing civil freedoms or imposing retribution on alleged sponsors – thus
contradict the fundamental values of such regimes. As Crenshaw points out, governments
risk becoming ‘the victims of their own stereotype of terrorism as responsive only to force’.18
Consequently, government crackdowns on extremists, and accompanying policies that limit
political freedoms and rights, undermine the government’s legitimacy and can increase
support for terrorist groups, facilitate terrorist recruitment, and prolong the lifespan of
terrorist groups.19
Such backlashes are particularly likely if counter-terrorist measures do not discriminate
between supporters of terrorist organizations and innocent citizens.20
Proactive measures
may thus increase popular sympathies for terrorist groups’ grievances, and could even
boost terrorist recruitment. As Rosendorff and Sandler point out, coercive tactics ‘may
have a downside by creating more grievances in reaction to heavy-handed tactics or
unintended collateral damage’.21
We propose three mechanisms to explain why elites in
democracies experience backlash effects.22
First, we argue that the use of harsh policies reduces local communities’ co-operation
with government authorities. Since terrorism is a relatively rare and dispersed form of
violence, effective counter-terrorism policing depends on complete, accurate and welltimed
information from local communities.23
However, intrusive government actions in
18
Martha Crenshaw, ‘How Terrorism Declines’, Terrorism and Political Violence, 3 (1991), 69–87,
p. 74.
19
T. David Mason and Dale A. Krane, ‘The Political Economy of Death Squads: Toward a Theory of
the Impact of State-Sanctioned Terror’, International Studies Quarterly, 33 (1989), 175–98; Bueno de
Mesquita and Dickson, ‘The Propaganda of the Deed’; Walsh and Piazza, ‘Why Respecting Physical
Integrity Rights Reduces Terrorism’.
20
Consequently, we hypothesize that only indiscriminate forms of repression would have the expected
effect on group termination in democracies. Ideally, our empirical test would allow for an explicit
distinction between selective and indiscriminate forms of repression, but no such data are available crossnationally.
The empirical analysis uses data from the PTS by Gibney, Cornett and Wood and the CIRI
data by Cingranelli and Richards to measure repression. While neither of these sources explicitly
distinguishes between selective and indiscriminate forms, high levels of state repression in both data
sources indicate that repression is widespread and that there is little to no regard for physical integrity
rights. For example, the PTS data specify that civil and political rights violations such as disappearances,
murder or imprisonment have expanded to large parts of the population in countries with repression
scores of 4, and to the whole population for countries with scores of 5. High levels of repression thus likely
approximate conditions in which the state applies repression indiscriminately. See Mark Gibney, L.
Cornett and Reed Wood, ‘Political Terror Scale 1976–2006’, available at http://www.politicalterror
scale.org/; David L. Cingranelli and David L. Richards, ‘The Cingranelli-Richards (CIRI) Human Rights
Dataset’, available at http://ciri.binghamton.edu/.
21
Rosendorff and Sandler, ‘Too Much of A Good Thing?’, p. 658.
22
The argument raises the question of why democracies would use repressive strategies in the first
place. Research by Bueno de Mesquita and Kydd and Walter suggests one possible explanation. The
authors argue that democracies may have to resort to more public and less discriminatory practices when
engaging in counterterrorism. Democratic governments are under pressure to ‘do something’ in response
to terrorist violence, and less visible strategies can create the perception that the government is not
protecting the population. See Ethan Bueno de Mesquita, ‘The Quality of Terror’, American Journal of
Political Science, 49 (2005), 515–30; Kydd and Walter, ‘The Strategies of Terrorism’.
23
Richard Posner, Countering Terrorism: Blurred Focus, Halting Step (Lanham, Md.: Rowman &
Littlefield, 2007); Tom R. Tyler, Stephen Schulhofer and Aziz Z. Huq, ‘Legitimacy and Deterrence Effects
in Counterterrorism Policing: A Study of Muslim Americans’, Law & Society Review, 44 (2009), 365–402.
Government Responses and Terrorist Campaigns 563
response to terrorist threats can undermine government legitimacy and estrange local
communities from government authorities.24
Hence, government responses that are
perceived as harsh and excessive can lead individuals to withhold information out of fear
of unfair treatment. Surveys of Muslims in the United States and the United Kingdom
show that their willingness to alert the police to threats is ‘negatively affected by the
belief that Muslims are subject to discrimination’.25
Research has also documented that
perceptions of intrusive police tactics against Muslim Americans can reduce non-Muslims’
perceptions of the police as legitimate.26
Secondly, harsh counter-terrorism policies can increase popular sympathy for the group’s
cause and subsequently spur recruitment for terrorist organizations in democratic regimes.27
Coercive responses that undermine a government’s legitimacy can thus increase: overall
support for a terrorist group, the number of potential recruits and the resources available to
the group.28
Accounts of the escalation of violence in several democracies illustrate this
dynamic. Several studies of the Northern Ireland conflict emphasize that coercive government
measures in the 1970s helped drive the growth and intensity of the IRA during this period.29
Similarly, Della Porta’s analysis of counter-terrorism in Italy emphasizes how hard-line
policies can produce counterproductive results by ‘stiffening individuals as regards their own
choices and increasing solidarity outside’.30
In addition, harsh government tactics against
terrorism in Israel have reportedly resulted in a large number of civilian casualties, which can
fuel the cycle of violence by mobilizing new supporters and strengthening the motivation of
group members.31
Thirdly, we expect that democratic states’ use of repression will jeopardize their ability to
combat terrorism more generally. Democratic leaders are accountable to the public and
can be removed from office if their counter-terrorism policies are perceived as unnecessarily
harsh and excessive. The use of coercive measures undermines the values that democratic
regimes represent, and can thus threaten the survival of leaders. Leadership turnover
may result in changes to counter-terrorism policies that can subsequently reduce the
government’s effectiveness in combating terrorist groups.32
Moreover, simply being
24
Laura K. Donohue, The Cost of Counterterrorism: Power, Politics, and Liberty (Cambridge:
Cambridge University Press, 2008).
25
Tyler, Schulhofer and Huq, ‘Legitimacy and Deterrence Effects in Counterterrorism Policing’,
p. 380.
26
Aziz Z. Huq, Tom R. Tyler and Stephen J. Schulhofer, ‘Why Does the Public Cooperate With Law
Enforcement? The Influence of the Targets and Purposes of Policing’, Psychology, Public Policy, and Law,
17 (2011), 419–50, pp. 429–31.
27
Gary LaFree and Gary Ackerman, ‘The Empirical Study of Terrorism: Social and Legal Research’,
Annual Review of Law and Social Science, 5 (2009), 347–74.
28
Abrahms, ‘Why Democracies Make Superior Counterterrorists’; LaFree and Ackerman, ‘The
Empirical Study of Terrorism’; Walsh and Piazza, ‘Why Respecting Physical Integrity Rights Reduces
Terrorism’.
29
See Sanchez-Cuenca and de la Calle, ‘Domestic Terrorism’, p. 42; LaFree, Dugan and Korte, ‘The
Impact of British Counterterrorist Strategies on Political Violence in Northern Ireland’.
30
Della Porta, ‘Leaving Underground Organizations’, p. 84.
31
The Israeli response to terrorist activity is widely seen as more aggressive than most modern
democracies. See Parker, ‘Fighting an Antaean Enemy’, p. 163.
32
While we are not aware of research that systematically evaluates the effect of repression on
leadership removal, Iqbal and Zorn’s analysis of leader assassinations shows that repression increases the
risk of assassination in open-selection systems (that is, democracies) with weak executives. Zaryab Iqbal
and Christopher Zorn, ‘Sic Semper Tyrannis? Power, Repression, and Assassination Since the Second
World War’, Journal of Politics, 68 (2006), 489–501.
564 DAXECKER AND HESS
threatened with removal can produce inconsistent counter-terrorism policies, since
democratic leaders may decide to ‘change policies midstream’ to avert popular criticism.33
In addition, Walsh and Piazza maintain that opposition parties will try to gain political
capital by criticizing counter-terrorism policies, which will likely reduce the overall
resources devoted to counter-terrorism.34
Repression and Terrorist Group Duration in Non-Democratic Regimes
We expect that coercive government action can successfully deter terrorist group survival in
non-democratic regimes, because authoritarian leaders are less dependent on whether their
counter-terrorism policies are perceived as legitimate.35
First, we do not expect repression to
deter public co-operation in authoritarian regimes. Since repression is more common in nondemocratic
regimes, government legitimacy is already low. Research in the criminology
literature shows that legitimacy becomes largely irrelevant for public co-operation when
governmental abuse is considered an inevitable fact of life.36
Compliance in authoritarian
regimes is thus likely to be driven by fear of punishment rather than legitimacy, so coercive
counter-terrorism strategies are unlikely to further reduce community co-operation with the
government.
Secondly, we anticipate that repressive measures by authoritarian regimes can successfully
depress recruitment for terrorist groups. Gathering information on suspected terrorists and
their sympathizers (and detaining them without trial) is unlikely to lead to backlash effects,
because authoritarian governments can suppress information about their actions and curtail
media reports.
Finally, leaders of authoritarian regimes are not as constrained in their counterterrorism
efforts as their democratic counterparts because they are less dependent on
public opinion for remaining in office.37
Legal and normative constraints are subordinate
in authoritarian regimes’ responses to anti-government violence.38
Authoritarian leaders
can thus be less concerned with the public’s response to repressive counter-terrorism
policies or the electoral consequences of such actions.39
33
Walsh and Piazza, ‘Why Respecting Physical Integrity Rights Reduces Terrorism’, p. 559.
34
Walsh and Piazza, ‘Why Respecting Physical Integrity Rights Reduces Terrorism’.
35
Our focus on authoritarian regimes as a single category neglects potential variations in the
importance of legitimacy considerations across different types of authoritarian regimes. While developing
an argument that takes these differences seriously is beyond of the scope of this article, the robustness
tests include an exploratory analysis.
36
Justice Tankebe, ‘Public Co-operation With the Police in Ghana: Does Procedural Fairness
Matter?’’ Criminology, 47 (2009), 1265–93; Eric G. Lambert, Shanhe Jiang, Mahfuzul I. Khondaker, O.
Oko Elechi, David N. Baker and Kasey A. Tucker, ‘Policing Views From Around the Globe: An
Exploratory Study of the Views of College Students From Bangladesh, Canada, Nigeria, and the United
States’, International Criminal Justice Review, 20 (2010), 22–47. Note that these studies focus on public cooperation
with police in general and not terrorism, but their findings should extend to public co-operation
in counterterrorism policies.
37
Kydd and Walter, ‘The Strategies of Terrorism’; Robert A. Pape, Dying to Win: The Strategic Logic
of Suicide Terrorism (New York: Random House, 2005).
38
Goldie Shabad and Francisco Jose´ Llera Ramo, ‘Political Violence in a Democratic State: Basque
Terrorism in Spain’, in Martha Crenshaw, ed., Terrorism in Context (University Park: Pennsylvania State
University Press, 1995), pp. 410–73.
39
We are not arguing that non-democratic leaders are completely insulated from public opinion and
electoral concerns. However, while elections are now held in the vast majority of countries, nondemocratic
regimes frequently limit or prohibit the participation of opposition candidates and incumbents
often manipulate the electoral process.
Government Responses and Terrorist Campaigns 565
Therefore our main hypothesis expects the effects of repression on group duration to vary
by regime type. Coercive measures in democracies constrain the civil rights and liberties
expected by citizens and thus inadvertently increase the resilience of terrorist groups.
Conversely, proactive measures are expected to be successful in deterring the use of terrorism
and reducing the lifespan of terrorist organizations in non-democratic regimes.
HYPOTHESIS 1: Repression reduces the hazard of terrorist group termination in democracies,
but increases the hazard of terrorist group termination in nondemocratic
regimes.
REPRESSION, REGIME TYPE AND THE OUTCOME OF TERRORIST CAMPAIGNS
We now turn to the implications of our argument for terrorist campaign outcomes. We
distinguish between four main endings for terrorist campaigns: government victory,
political settlement, group victory or splintering. Since these outcomes vary in the extent
to which they are desirable from the perspective of the government and the terrorist
group, evaluating group termination in the aggregate risks masking substantial variation
in the influence of repression on these outcomes. We expect that repression makes
outcomes favourable to the government less likely in democratic regimes, but more likely
in authoritarian regimes.
Government victory and negotiated settlements likely represent the most favourable
outcomes for governments. Because we suspect that repression has counterproductive
effects in democracies, we anticipate that its use will reduce the likelihood of such
outcomes in democracies. Conversely, because harsh government responses are not
expected to harm the government’s counter-terrorism efforts in authoritarian regimes, we
expect that repression will increase the chance of government victory or settlement in
these regimes.
HYPOTHESIS 2: Repression reduces the hazard of government victory or political settlement
in democracies, but increases the hazard of government victory or
political settlement in non-democratic regimes.
A victorious terrorist group is likely the least desirable outcome from the perspective of
the government. The logical implication of our argument thus suggests the opposite
expectation for campaigns ending with a group victory.40
We expect that repression will
increase the likelihood of group victory in democracies because of backlash effects, but
reduce the probability of group victory in non-democratic regimes.
HYPOTHESIS 3: Repression increases the hazard of group victory in democracies, but
decreases the hazard of group victory in non-democratic regimes.
The final possible outcome is terrorist campaigns that break up or splinter. The
implications of our argument are most ambiguous with regard to splinters, especially
since splintering might be a favourable outcome for the government in some cases but
unfavourable in others. In some instances, splintering could be the result of successful
government pressure if extremist elements break apart because moderate group members
switch to nonviolent tactics. Yet in other cases, splinter groups could continue using
40
Cases of group success are empirically rare. Of all groups that ended their campaigns in our data,
only 6.6 per cent of cases resulted in a group victory.
566 DAXECKER AND HESS
terrorist tactics to undermine negotiations with the government.41
Consequently, it is
unlikely that repression and regime type have systematic effects on splintering. Therefore
we do not develop expectations on the likelihood of splintering.
EMPIRICAL ANALYSIS
Data
We evaluate our theoretical arguments in a statistical analysis of 539 terrorist groups in
eighty-five countries for the 1976–2006 period.42
We use data on terrorist organizations
collected by the RAND-MIPT project and presented in Jones and Libicki. Our unit of
analysis is the group-year; the last year of observation is 2006 (or earlier, if the group
terminated prior to that date). The data include terrorist organizations that carried out
international incidents before 1998 and organizations that carried out international or
domestic incidents from 1998–2006. We include terrorist groups engaging in both domestic
and transnational terrorism for several reasons. First, Jones and Libicki identify the
host country (the country in which groups base their operations) rather than the target
country (the country experiencing the violence) for terrorist organizations carrying out
international incidents.43
Our empirical analysis investigates how government responses in
the host country (in which groups base their operations) affect group duration, rather
than government responses in the country that is targeted. Secondly, the RAND-MIPT
database’s definition of international terrorism includes many incidents committed by
groups to which our theoretical argument should apply rather straightforwardly. Terrorist
events are defined as international if terrorists go abroad to strike their targets, select victims
or targets with foreign connections or attack airlines’ personnel or equipment.44
For attacks
that occur within a host country and are thus in the natural environment of the group
(the second and third categories of international terrorism), responses from that government
should clearly be relevant for group duration. For example, the data include groups such as
41
Moreover, splintering could be the result of competition among different groups within the same
state, and thus be the result of groups competing over material resources and popular support rather than
the government’s actions. See Kydd and Walter, ‘The Strategies of Terrorism’. The proliferation of
terrorist groups in Pakistan is an example of such a dynamic.
42
Jones and Libicki provide a list of all terrorist organizations and group attributes in their appendix.
The data cover 648 terrorist groups between 1968 and 2006 and provide start and end dates for all groups,
including those that did not terminate their campaigns by 2006. The RAND-MIPT data used to create
their list of terrorist groups is available at http://www.rand.org/nsrd/projects/terrorism-incidents.html.
Jones and Libicki include a few terrorist groups in colonies that were active before the country’s
independence, such as the Armed Revolutionary Action group in Mozambique. We excluded such groups
from the analysis until states achieved independence. Data limitations on the repression variable limit our
time frame to the 1976–2006 period. Jones and Libicki, How Terrorist Groups End, pp. 142–86.
43
Jones and Libicki identify a single host country for 430 of 539 groups in our sample. See Jones and
Libicki, How Terrorist Groups End. For the remaining 109 groups, two or more states are identified as
host countries. To identify the primary host for these groups, we consulted the list of terrorist groups
provided by the Terrorism Knowledge Base (TKB), which formed the basis of the data on terrorist groups
included in RAND-MIPT. The TKB provides a narrative of each group’s evolution and frequently
refers to the country in which groups organize the majority of their operations. The TKB data are
available online at http://www.start.umd.edu/start/data_collections/tops. For groups without additional
information, we consulted the RAND-MIPT data to determine the country in which groups carried out
the majority of their attacks.
44
Bruce Hoffman, ‘The Confluence of International and Domestic Trends in Terrorism’, Terrorism and
Political Violence, 9 (1997), 1–15.
Government Responses and Terrorist Campaigns 567
the African National Congress (ANC) because it engaged in attacks against international
corporations in South Africa, yet the ANC’s goal was arguably to establish racial equality
in South Africa. Finally, we think our argument may also apply to groups that target
internationally. While repressive government measures may not be aimed at groups that
carry out attacks in other countries, coercion that affects large parts of the population would
likely also affect the capabilities of such groups.45
A robustness test excluding groups
that target internationally is presented in the online appendix and shows support for our
main contention.
Dependent Variables
The first dependent variable is used to evaluate our hypothesis on group termination. It is
a dummy variable coded 0 for each year that a particular group was in operation, and 1
for the year in which the group terminated. Groups still active in 2006 were coded as 0 in
the last year of observation. Of the 539 groups studied, 322 groups ended their campaigns
during 1976–2006. Data on start and end dates of terrorist organizations come from Jones
and Libicki.46
Jones and Libicki used the following criteria to code the beginning and end
of terrorist campaigns:
The start year of a terrorist group was assigned based on first indication that the group existed
and was dedicated to the use of violence. The end year of a terrorist group was assigned based
on earliest evidence that the group no longer used terrorism to achieve its goals. This may be
because security forces captured and killed most of its members, the group reached a peace
agreement with the government, its members shifted to nonviolent means to achieve their
goals, or its members splintered to join other groups or start new ones. Regardless of the
reason, the group did not commit further terrorist attacks under its name.47
Jones and Libicki provide information on how terrorist campaigns end, which we used
to create four additional dependent variables to examine the outcome of terrorist
campaigns: government victory, political settlement, group victory and splintering.48
Table 1 presents the distribution of terrorist campaign outcomes for the 322 groups that
T A B L E 1 Terrorist Campaign Outcomes, 1976–2006
Variables N %
Government victory 101 31.37
Political settlement 94 29.19
Group victory 21 6.52
Splinter 106 32.92
Total 322 100
45
Moreover, it is possible that such groups simultaneously engage in domestic attacks, since the two
types of attacks are not mutually exclusive. The frequency with which groups target both domestically
and across borders should ultimately be an empirical question, but we are not aware of research that
addresses this question.
46
While Jones and Libicki’s empirical analysis excludes ongoing campaigns, their appendix provides
information on groups that have not terminated. Jones and Libicki, How Terrorist Groups End.
47
Jones and Libicki, How Terrorist Groups End, p. 5.
48
Jones and Libicki’s categories are very similar to ours, but the authors further separate government
victory into ‘victory through policing’ and ‘victory through military force’. Since terrorist groups that end
568 DAXECKER AND HESS
ended their campaigns in the period under analysis. The table shows that splinters,
government victory and settlement are approximately equally common, whereas group
victory is by far the least likely outcome of terrorist campaigns.
Independent Variables
The data provided in Jones and Libicki include information on a number of group
characteristics that we append with state-level characteristics, described in more detail
below.49
The first independent variable measures the level of repression in states. Data for
this variable were obtained from the Political Terror Scale (PTS).50
The variable is coded
1 through 5, ranging from least repressive to most repressive.51
The second key independent
variable measures how democratic countries are; it is taken from the Polity IV Project
data.52
The scale for this variable ranges from 210 (fully authoritarian) to 110 (fully
democratic).53
To model the interaction between repression and regime type outlined in the
first hypothesis, we create an interaction variable by multiplying the repression and
democracy variables.54
Additional variables control for other group and state characteristics that likely affect
group termination. Data for all group characteristics come from Jones and Libicki.55
First, group size has been shown to affect the likelihood of group termination in previous
research: larger groups have greater longevity. The measure of the size of the terrorist
(F’note continued)
because of policing and military force represent an achievement of the government’s goals, we collapse
these two categories. Jones and Libicki, How Terrorist Groups End.
49
Jones and Libicki, How Terrorist Groups End, pp. 142–85.
50
Gibney, Cornett and Wood, ‘Political Terror Scale 1976–2006’.
51
A score of 1 indicates that a country is under a secure rule of law, people are not imprisoned for their
views, torture is rare or exceptional, and political murders are extremely rare. Countries that have a
limited amount of imprisonment for nonviolent political activity were rated as a 2. Those with extensive
political imprisonment, common executions or political murders and brutality, and unlimited detention
for political views receive a score of 3 on the PTS. A rating of 4 indicates that a country violates the
political and civil rights of a large portion of the population and that murder, disappearances and torture
are a common part of life, especially for those who interest themselves in politics and ideas. Finally, a
rating of 5 indicates that terror has expanded to the entire population of the country, and the leaders are
not limited in the way they pursue personal or ideological goals. The PTS data provide scores for both
Amnesty International and US State Department rankings; we average the two scores, meaning that the
repression variable can take empirical values of 1, 1.5, 2, 2.5 and so forth.
52
Monty G. Marshall and Keith Jaggers, ‘Polity IV Project: Political Regime Characteristics and
Transitions, 1800–2007’, available at http://www.systemicpeace.org/polity/polity4.htm.
53
Of all countries in the data, 68 per cent are democracies with polity scores of 6 or higher.
54
One might object that findings based on this interaction are the result of a small number of cases,
since repression and democracy likely co-vary. While we do not dispute that democracies, on average,
have lower levels of repression than non-democratic regimes, numerous case studies document the use of
coercive strategies in democracies. Moreover, a cross-tabulation of the repression and polity variables
showed that 30 per cent of all democracies with polity scores of 6 or greater score 4 or higher on the
repression variable. When only highly democratic countries (polity scores of 8 or greater) are included, the
percentage of democracies engaging in such levels of repression decreases to 26 per cent. Although
research by Davenport and Armstrong suggests that democracies exhibit lower levels of repression only
when high levels of democracy are reached, one-fourth of highly democratic states in our data apply high
levels of repression. Conversely, 13 per cent of non-democratic regimes have repression levels lower than
3. Christian Davenport and David A. Armstrong, ‘Democracy and the Violation of Human Rights’,
American Journal of Political Science, 48 (2004), 538–54.
55
Jones and Libicki, How Terrorist Groups End.
Government Responses and Terrorist Campaigns 569
group is an ordinal variable coded 1 for less than 100 people, 2 for 100–999, 3 for
1,000–9,999 and 4 for 10,000 or more.56
Secondly, the previous literature also identifies terrorist groups’ ideological views as a
significant factor that affects group longevity; religious terrorist organizations are more
durable than leftist or right-wing groups. We separate the ideology measures from Jones
and Libicki into four dummy variables:57
nationalist groups, religious groups, leftist
groups and right-wing groups.58
In our models, right-wing groups are the excluded
category because they were least represented in the data.
Thirdly, we control for the breadth of terrorist goals. This measure is coded as an ordinal
variable according to the scope of the groups’ goals.59
A fourth control variable incorporates
information about the number of countries in which individual terrorist organizations operate
or have bases of support. The foreign presence variable is a dummy coded 0 if the terrorist
group is based in only one state and 1 if the group is present in two or more states.
Two additional variables account for other state characteristics. Gross domestic
product (GDP) per capita – gathered from the Penn World Tables60
– serves as our
measure of state economic development. Data for population size come from the World
Bank’s World Development Indicators.61
Methodology
We use a Cox proportional hazards model to estimate the hazard of group termination,
our first dependent variable. The model allows us to estimate the hazard function
by predicting the failure or termination of conflict within a particular time interval.
The hazard rate for any observation i at time t is given by the function hi(t)5h0(t) exp (x0
tb),
where h0(t) is the baseline hazard of the event. In this type of model, hazard rates are only
calculated as failures and are not sensitive to distribution issues because the baseline
hazard rate cancels out when the hazard ratio is taken in the event of a failure. We use
a stratified Cox model to analyse terrorist campaign outcomes, the second set of
dependent variables in our empirical analyses.62
This model lets us estimate the effect of
56
This variable does not change over time. While it would be ideal to use a time-varying covariate, no
such data are available.
57
Jones and Libicki, How Terrorist Groups End.
58
Nationalist groups were most represented in our sample, representing 38.2 per cent of cases, followed
by leftist groups with 33.4 per cent and religious groups with 23.2 per cent; right-wing groups represented
only 5 per cent of all cases.
59
The variable ranges from 1–6, where lower values indicate that the group’s goals are more limited,
and greater values represent more extensive goals. Groups are coded as 1 if their goal is to maintain the
status quo, 2 if their goal is policy change, 3 if their primary goal is regime change, 4 if their goal is
territorial change, 5 if their goal is revolution and 6 if their goal is empire. Since group goals could be
correlated with group ideology and such multicollinearity could mask the statistical significance of
covariates, we specified separate models excluding the group goal and ideology variables, respectively.
The results remained similar to the ones presented here. In addition, correlation matrices for the variables
did not show correlations greater than 0.16.
60
Alan Heston, Robert Summers and Bettina Aten, ‘Penn World Table Version 6.3: Center for International
Comparisons of Production, Income and Prices at the University of Pennsylvania’, available at http://
pwt.econ.upenn.edu/php_site/pwt_index.php. The natural log was taken because of high skewness in the data.
61
Data are available at http://publications.worldbank.org/WDI/. The variable was logged in order to
achieve a normal distribution.
62
A Hausman test showed that the outcomes are independent of each other. Results for a multinomial
logit model were similar.
570 DAXECKER AND HESS
covariates on a particular terrorist campaign outcome, rather than estimating the average
effect of independent variables across different outcomes.63
One restriction imposed on the Cox model is the assumption of proportionality,
meaning that the effect of the covariates on the hazard ratio has to be proportional during
the lifespan of a terrorist group. Tests of the proportional hazards assumption indicated
evidence of non-proportionality for several independent variables, in particular the group
size variable.64
We follow Box-Steffensmeier and Jones’ advice and deal with time-varying
covariates by interacting such variables with the logarithm of time.65
In the following tables for group duration and outcomes, the hazard ratio is a covariate’s
effect on the baseline hazard of group termination.66
Hazard ratios smaller than 1 indicate
that an independent variable reduces the hazard rate of event occurrence within a specified
time interval, and ratios larger than 1 mean that an independent variable increases the
hazard rate of event occurrence. The statistical significance of hazard ratios is measured
using two-tailed tests, and all models employ robust standard errors.67
DATA ANALYSIS
Terrorist Campaign Duration
Table 2 presents the results for models of terrorist group duration. The first model in
Table 2 includes all independent variables except the product term. In this model, findings
for the polity variable mirror past studies that found no significant relationship between
this indicator and terrorist group termination. Similarly, the hazard ratio for the
repression variable is negative but insignificant. Previous large-sample studies have not
included a measure for repression, and our findings suggest that repression does not affect
group termination independently.
Among the control variables, the coefficient for population is negative and significant,
indicating that the larger the population of a particular country, the less likely it is that
terrorist groups will terminate. The variable for group size is significant and negative,
which indicates that larger groups are less likely to fail. Nationalist terrorist groups are
less likely to terminate than right-wing terror groups (the excluded category). With regard
to terrorist group goals, we find that groups with more extensive aims are less likely to
end their campaigns than groups pursuing less ambitious goals. Coefficients for the GDP
per capita variable, leftist groups, religious groups and the variable for a group’s foreign
presence are not significant.
63
Janet Box-Steffensmeier and Bradford S. Jones, Event History Modeling (Cambridge: Cambridge
University Press, 2004).
64
Tests for non-proportionality produced different results for different models. The group size variable
showed time-varying effects in all empirical models that include group characteristics. In addition to
group size, the variables measuring democracy, population size, religious groups, nationalist groups and
whether a group has a foreign presence showed signs of non-proportionality in some (but not all) models.
We include interactions between the logarithm of time and the respective variables for time-varying
variables in all models in which tests showed evidence of non-proportionality for respective variables. In
order to preserve space, hazard ratios for time-interactions are not presented.
65
Box-Steffensmeier and Jones, Event History Modeling, p. 136.
66
In competing risk models, subhazard ratios are presented; they represent the effect of covariates on
the hazard of the four terrorist campaign outcomes.
67
We also analysed models with standard errors clustered on the group’s host country. Results were
similar to the ones presented here.
Government Responses and Terrorist Campaigns 571
The second model in Table 2 includes the interaction term. The hazard ratio is
significant and negative (z 5 22.69), indicating that repression is a counterproductive
strategy in democracies because it decreases the risk of terrorist group termination, but
increases the hazard of termination in authoritarian regimes. This finding supports
Hypothesis 1, which expected that the effect of repression varies with regime type. The
results for the control variables are similar to the first model. The third model in Table 2
presents the results for a parametric model with a Weibull hazard function. While the
Weibull model is more restrictive than the non-parametric Cox model in assuming that
the underlying shape parameter is known, the results show that our findings are robust to
alternative estimation techniques.68
The hazard ratio for the interaction is negative and
significant. The control variables are similar to the first two models in Table 2, although
we find that religious groups (rather than nationalist groups) are less likely to terminate
than right-wing organizations in the Weibull model.
Table 3 presents substantive effects for all models in Table 2. We first discuss
substantive effects for the interaction in the Cox model. When the polity variable is set at
T A B L E 2 The Determinants of Terrorist Group Termination
Cox base model Cox model with interaction Weibull model
Variables Hazard ratio (S.E.) Hazard ratio (S.E.) Hazard ratio (S.E.)
Repression 0.963 1.121 1.128
(0.050) (0.101) (0.094)
Polity 0.985 1.074* 1.081*
(0.012) (0.038) (0.041)
Repression 3 polity – 0.976** 0.976*
(0.009) (0.009)
GDP per capita (log) 1.010 0.951 0.963
(0.075) (0.074) (0.082)
Population (log) 0.893** 0.886** 0.872**
(0.025) (0.025) (0.030)
Size 0.283** 0.287** 0.449**
(0.040) (0.041) (0.043)
Leftist 0.773 0.776 0.774
(0.129) (0.130) (0.163)
Religious 0.685 0.708 0.395**
(0.179) (0.183) (0.112)
Nationalist 0.677* 0.700* 0.740
(0.119) (0.122) (0.159)
Goal breadth 0.915* 0.915* 0.896*
(0.035) (0.035) (0.044)
Foreign presence 0.787 0.775 0.967
(0.148) (0.149) (0.159)
N 4,979 4,979 4,979
Wald x2
157.73 172.87 140.21
Note: Hazard ratios with robust standard errors in parentheses are reported.
**p , 0.01; *p , 0.05 (two-tailed tests)
68
Results for other distributional forms – such as the exponential, log-logistic and Gompertz
distribution –were similar to the ones reported.
572 DAXECKER AND HESS
10, the repression variable is varied from 1.5 to 4.5 and the interaction is varied along with
the respective values of the constitutive terms, the hazard of group termination decreases
by 33 per cent. Conversely, repression increases the likelihood of terrorist group failure in
non-democratic regimes. Setting the polity variable at 23, varying the repression variable
from 1.5 to 4.5 and varying the interaction along with the respective values of the
democracy and repression variables produces a 76 per cent increase in the hazard rate of
termination. Substantive effects for the Weibull model are more meaningful to interpret,
as they indicate the change in the expected duration of terrorist groups. For democracies,
the expected duration of terrorist groups increases from thirteen to twenty-one years
if the repression variable and the interaction are varied from 1.5 to 4.5. Conversely, the
duration of groups in authoritarian regimes decreases from twenty-five to thirteen years if
the repression variable is varied from 1.5 to 4.5, together with the interaction.
Figure 1 is based on the second model in Table 2 and illustrates the effect of repression
on the likelihood of failure in democratic and non-democratic states.69
In this figure, the
T A B L E 3 The Determinants of Terrorist Group Termination (Substantive Effects)
Cox base model
Cox model with
interaction Weibull model
Variables
Change in hazard
rate (%D)
Change in hazard
rate (%D)
Change in
duration (%D)
Repression in democraciesa
1.5 (21SD) – 0.004 13.5
4.5 (11SD) 0.003 (232.7) 20.6 (152.2)
Repression in non-democraciesb
1.5 (21SD) – 0.003 25.5
4.5 (11SD) 0.005 (176.2) 12.9 (249.4)
Population (log)
15.7 (21SD) 0.005 0.005 10.9
19.7 (11SD) 0.003 (236.0) 0.003 (237.8) 20.5 (188.4)
Size
1 (21SD) 0.016 0.016 5.4
3 (11SD) 0.001 (291.9) 0.001 (291.8) 35.6 (1560.6)
Nationalist group
0 (min) 0.004 0.004
1 (max) 0.003 (232.3) 0.003 (230.0) –
Religious group
0 (min) – – 12.6
1 (max) 37.7 (1198.5)
Goal breadth
2 (21SD) 0.004 0.004 13.0
5 (11SD) 0.003 (223.3) 0.003 (223.3) 19.2 (147.2)
a
Polity is set at 10 (11 SD from the mean) and repression is varied from 1.5 to 4.5 ( 61 SD
from the mean) together with the interaction to calculate marginal effects on the hazard rate in
democracies.
b
Polity is set at 23 (21 SD from the mean), repression is varied from 1.5 to 4.5 ( 61 SD)
together with the interaction to calculate marginal effects on the hazard rate in non-democracies.
69
We cannot include time-interactions in this model because the command used to create the figure
does not allow for their inclusion.
Government Responses and Terrorist Campaigns 573
first graph depicts the effect of repression on group termination when the democracy
variable is set at 10 (11 SD from the mean) and the second graph presents the same effect
when the democracy variable is set at 23 (21 SD from the mean). In both graphs,
repression is varied from 1.5 to 4.5 (61 SD from the mean), and the interaction is varied
along with the respective values of the constitutive terms. The first graph in Figure 1
illustrates the effect of repression on group termination in democratic states. High
repression in democracies, as represented by the solid line, results in lower rates of
termination than low levels of repression, as represented by the dotted trend line. The
opposite effect is observed in the second graph shown in Figure 1. For non-democracies,
higher repression (solid line) leads to substantially higher cumulative hazard ratios and
therefore a greater likelihood of terrorist group termination over time than low repression
(dotted line). Taken together, the results presented in Tables 2 and 3 and illustrated in the
figure support our expectations.
Terrorist Campaign Outcomes
Next we evaluate how repression and democracy influence the outcome of terrorist campaigns.
Two caveats are necessary before we discuss our empirical results presented in Table 4. First,
the results for our outcome models are based on a small number of data points, in particular
for campaigns ending with a terrorist group victory (an outcome observed in less than
7 per cent of campaigns that ended). Secondly, it may be difficult to determine, in practice,
whether an outcome was in fact favourable to the government or the group. A government
victory, for example, may come only after a protracted and costly counter-terrorism
campaign, such as the Sri Lankan government’s defeat of the Tamil Tigers in 2009.
The second hypothesis expects that repression in democracies reduces the likelihood of
government victory and settlements, outcomes that are more favourable for governments.
0.0
0.5
1.0
1.5
2.0
Cumulativehazard
0 10 20 30 40
Analysis time
Low
repression
High
repression
Democracies
0.0
0.5
1.0
1.5
2.0
Cumulativehazard
0 10 20 30 40
Analysis time
Low
repression
High
repression
Non-democracies
Fig. 1. The effect of repression on terrorist group duration
574 DAXECKER AND HESS
We find partial support for this hypothesis. The hazard ratio for the interaction between
the repression and polity variables is negative in both the government victory and
settlement models, but reaches statistical significance only for terrorist campaigns that
resulted in political settlements (z 5 21.99). While we expected that government coercion
would be counterproductive for all outcomes favourable for the government, it is
interesting to observe that repression in democracies appears particularly damaging for
outcomes in which governments depend on groups’ willingness to enter negotiations and
come to a mutual agreement. Coercive responses thus appear to be less influential for
outcomes in which governments are capable of imposing their preferred outcome.
The model for group victory shows support for Hypothesis 3. The hazard ratio for the
interaction is positive and significant (z 5 2.20), which demonstrates that repressive
measures increase the risk of group victory in democracies, but reduce the hazard
of group victory in authoritarian regimes. As expected in Hypothesis 3, we find that
the effect of coercive responses is reversed for outcomes that are unfavourable for
governments. Our findings thus show the importance of distinguishing among different
outcomes rather than collapsing all groups that ended their campaigns into a single
category. As expected, we do not find a significant relationship between repression and
regime type for groups that end in splinters.
T A B L E 4 The Determinants of Terrorist Campaign Outcomes
Government victory Settlement Group victory Splinters
Variables
Hazard ratio
(S.E.)
Hazard ratio
(S.E.)
Hazard ratio
(S.E.)
Hazard ratio
(S.E.)
Repression 0.800 1.389y 0.437y 1.191
(0.169) (0.275) (0.206) (0.205)
Polity 0.985 1.158y 0.966 1.034
(0.082) (0.093) (0.105) (0.074)
Repression x polity 0.983 0.961* 1.088* 0.983
(0.021) (0.019) (0.042) (0.019)
GDP per capita (log) 1.021 1.077 0.665 1.013
(0.182) (0.144) (0.168) (0.133)
Population (log) 1.129* 0.814** 0.715** 0.935
(0.067) (0.051) (0.075) (0.041)
Size 0.320** 0.549** 0.713 0.262**
(0.080) (0.100) (0.314) (0.071)
Leftist 0.922 0.568* 1.495 2.354
(0.315) (0.153) (1.861) (1.428)
Religious 0.689 0.050** 4.94e-08
** 3.677y
(0.403) (0.038) (6.56e-08
) (2.464)
Nationalist 0.535y 0.362** 5.069 3.284y
(0.200) (0.114) (6.113) (2.018)
Goal breadth 1.020 0.740** 0.502** 1.169*
(0.068) (0.070) (0.103) (0.086)
Foreign presence 1.139 0.546 2.206 0.815
(0.473) (0.232) (1.801) (0.276)
N 5,013 5,024 5,027 5,026
Wald x2
71.26 124.04 4475.41 54.79
Note: Reported are hazard ratios with robust standard errors in parentheses.
**p , 0.01 *p , 0.05 yp , 0.1 (two-tailed tests).
Government Responses and Terrorist Campaigns 575
Some interesting findings emerge for other covariates in the outcome models.
Population size increases the likelihood of a government victory, but reduces the
likelihood of settlements or group victories. Findings for the group size variable show that
campaigns fought by larger groups are less likely to end with government victories,
settlements or splinters, but do not affect the hazard of group victories. Compared to
right-wing groups, leftist, religious and nationalist groups are less likely to negotiate
settlements to their campaigns. Yet we also find that religious groups are less likely to
defeat the government and more likely to splinter. The breadth of groups’ goals reduces
the hazard of settlement and group victory and increases the hazard of splintering, but has
no effect on government victory. We do not find evidence that GDP or foreign bases
affect terrorist campaign outcomes.
Robustness Tests
We conducted a large number of additional robustness tests to evaluate whether findings
for terrorist group duration are robust to the inclusion of potentially influential
observations, additional operationalizations of key independent variables, alternative
samples of terrorist organizations and terrorist attacks as the dependent variable. The
results for robustness tests are described in detail in the online appendix. Statistical
models that exclude splinter groups, groups that target internationally and insurgent
groups confirm that repression increases group duration in democracies but lengthens
terrorist campaigns in authoritarian regimes. The results also remain consistent when
we use Cingranelli and Richards’ measure on physical integrity rights.70
An additional
robustness check disaggregates authoritarian regimes and shows that personalist regimes
are less susceptible to backlash effects when using repression than other types of
authoritarian regimes. We also find that the conditional effects of repression and regime
type on group duration are supported for two alternative samples of terrorist groups.
Findings using data on terrorist groups from Asal and Rethemeyer and the Global
Terrorism Database (GTD) are largely consistent with earlier results.71
Finally, a
robustness check using terrorist attacks from the GTD as the dependent variable
demonstrates that the implications of our argument hold for the incidence of terrorism:
repression in democracies increases the likelihood of terrorist attacks, but reduces the
probability of incidents in authoritarian regimes.
CONCLUSION
In this article, we argued that the effect of repression on terrorist group termination is
conditional on countries’ regime type. In democracies, coercive tactics can have
counterproductive effects by jeopardizing citizens’ perceptions of the government’s
legitimacy. Coercive government responses in democracies can reduce the public’s
co-operation with government authorities and increase support for terrorist groups. Yet
since coercive measures are unlikely to change the government’s perceived legitimacy in
70
Cingranelli and Richards, ‘The Cingranelli-Richards (CIRI) Human Rights Dataset’.
71
Victor Asal and R. Karl Rethemeyer, ‘The Nature of the Beast: Organizational Structures and the
Lethality of Terrorist Attacks’, Journal of Politics, 70 (2008), 437–49. The GTD data are available at
http://www.start.umd.edu/gtd/ and are described in Gary LaFree and Laura Dugan, ‘Introducing the
Global Terrorism Database’, Terrorism and Political Violence, 19 (2007), 181–204.
576 DAXECKER AND HESS
authoritarian regimes, we expect that repression reduces the duration of terrorist
campaigns. An empirical analysis of 539 groups for the 1976–2006 period supports our
expectations on group duration, and these findings are robust to additional model
specifications. Evaluating the implications of our arguments for terrorist campaign
outcomes shows that repression decreases the likelihood of negotiated settlements in
democracies, but increases the hazard of group victory in democratic regimes.
For policymakers, our research indicates that using coercive, indiscriminate responses
to terrorism is counterproductive for democracies; thus limited and selective counterterrorism
strategies have the highest potential for success. Policy implications for
non-democratic states are more problematic, since our findings suggest that strong-arm
tactics can force terrorist groups to settle their claims. Yet iron-fist strategies can have
negative consequences even in non-democratic states, especially in the long run. While
repression may successfully end a terrorist campaign in the affected country, it can create
an exodus into other states. For example, Chechen rebels fled to surrounding republics in
response to the Russian government’s hard-line strategy.72
Indiscriminate repression,
while successful against terrorist groups in the short term, may also lead to widespread
opposition and eventual rebellion against authoritarian regimes in the long run. For
example, the use of repressive tactics in Egypt, while successful in extracting a ceasefire
from terrorist organizations such as al-Jama‘a al Islamiyya, arguably fueled popular
discontent against the regime and may have contributed to Mubarak’s overthrow in 2011.
Future research is necessary to investigate such possible consequences of repressive
counter-terrorism policies in authoritarian states.
72
Cronin, How Terrorism Ends, p. 133.
Government Responses and Terrorist Campaigns 577