Ethnicity, the State, and the Duration of Civil Wars
Julian Wucherpfennig
Center for Comparative and
International Studies
ETH Zürich
8092 Zürich, Switzerland
[email protected]
Kristian Skrede Gleditsch
Department of Government
University of Essex
Colchester CO4 3SQ
United Kingdom
[email protected]
Nils Metternich
Department of Government
University of Essex
Colchester CO4 3SQ
United Kingdom
[email protected]
Lars-Erik Cederman
Center for Comparative and
International Studies
ETH Zürich
8092 Zürich, Switzerland
[email protected]
Preliminary Draft. Please do not cite without the authors’ permission.
Paper prepared for the GROW-Workshop at the Peace Research Institute Oslo
18 June 2010
Abstract
Whereas previous research has focused primarily on how ethnicity may trigger civil war, its effect on
conflict duration remains disputed. We argue that ethnicity as such does not affect civil war duration.
However, if states implement discriminatory policies based on ethnicity, members of politically excluded
ethnic groups develop grievances that can make rebel organizations more durable. This argument
challenges the view that only cognitive aspects of ethnic identities, e.g. information, trust, or common
language, help to overcome collective action problems. We stress that state-induced grievances motivate
members of excluded ethnic groups to participate in enduring rebel organizations. In line with our
theoretical argument, we find that conflicts last longer if rebel organizations operate on behalf of politically
excluded ethnic groups. Contrary to what is assumed in the literature, state-induced grievances, and not
rigid identities, prolong civil wars.
1
Introduction
Ethnicity remains a contested factor in the study of civil war. Whereas previous research
has focused primarily on the role of ethnicity for the onset of civil war, its effect on the
duration of such conflicts remains both theoretically and empirically understudied. On a
most general level, the discussion revolves around whether ethnic wars systematically
differ from non-ethnic civil wars in regard to their characteristics, for example the factors
that cause their onset or how they are conducted. Ethnic wars are shaped by an ethnic
rather than ideological or economic agenda that characterizes the fighting. It is argued
that ethnic identities cannot be transcended and create a unique sense of belonging that
facilitates collective action and is reinforced through fighting. Proponents of the ethnic
versus non-ethnic conflict differentiation postulate that due to the rigid nature of ethnic
identities, ethnic conflicts quickly become intractable, are inherently difficult to resolve,
and thus last longer (Kaufmann 1996, 1998; Kaufman 2001, 2006; Horowitz 1985). The
opposite skeptical view implies that ethnic identities are merely a cover story concealing
underlying economic or private interests and do not affect the conflict dynamics (Mueller
2004). Moreover, other scholars highlight that ethnic identities can be – and frequently
are –transcended in civil wars (Kalyvas 2006). From this perspective, ethnicity as such
should not have a clear or consistent effect on the dynamics of fighting.
This discussion has far-reaching repercussions since it ultimately questions the distinction
between ethnic and non-ethnic conflicts. It also challenges the conceptualization of ethnic
groups as meaningful actors in civil wars. In this paper we argue that many of the
2
ambiguities and discussions in the literature stem from the failure to distinguish between
two conceptually different dimensions. First, we address the issue of agency in civil wars
by making a clear distinction between ethnic groups and rebel organizations, while
retaining both actor types in our model. Second, we reassess the role of the state by
highlighting the effect of exclusionary state policies along ethnic lines.
Our main argument is that ethnicity as such does not affect civil war duration. However,
if the state implements discriminatory policies based on ethnicity, members of politically
excluded ethnic groups develop grievances that facilitate the durability of rebel
organizations. This argument challenges the view that only cognitive aspects of ethnic
identities, e.g. information, trust, or common language, help to overcome collective
action problems. We stress that state-induced grievances motivate members of excluded
ethnic groups to participate in enduring rebel organizations. In contrast to previous
research, our explanation for conflict duration contains a strong political element that
stresses the ethno-political context of civil wars. In short, by focusing on state-induced
ethnic policies, we add causal depth to the linkage between ethnicity and conflict
duration.
In the remainder of the paper we put these theoretical considerations to an empirical test.
Drawing on a new dataset that systematically links rebel organizations to politically
relevant ethnic groups, we demonstrate that ethnicity indeed can prolong civil wars.
However, this effect is entirely driven by the subset of conflicts with state-induced ethnic
grievances. These grievances stem from state actions that systematically exclude specific
3
ethnic groups from access to state power. Thus, contrary to what is assumed by many
scholars, we find no evidence for an inherent effect of ethnicity. Rather, ethno-nationalist
state-policies shape conflict dynamics.
Civil War Duration and Ethnicity
By definition, fighting in civil wars occurs between the government and one or several
rebel organizations challenging the state through violent means with aim of overtaking
the state’s monopoly of force, either fully or for some limited territory (see Sambanis
2004 for differences between various operationalizations). What differentiates civil wars
from other types of violence, for example communal violence, is that the state must be
involved as an actor in the conflict. Yet, as highlighted by this literature review, many
studies simply assume the state away. Furthermore, the operational definition leaves
some ambiguity concerning the “other” actor challenging the state. As we point out in
this section, depending on the theoretical approach, the common choices are (1) ethnic
groups and (2) rebel organizations. Against the background of the existing literature, we
identify the necessity to specify the role of the state and theorize the linkage between
ethnic groups and rebel organizations.
Previous explanations for the dynamics of violence in civil wars can be classified by a
simple 2x2 typology given in Table 1. It differentiates between whether the government’s
challenger is defined as an ethnic group or a rebel organization, and whether the state is
4
conceptualized as an active or passive actor. The conceptual questions are: (1) who is the
non-state actor, and (2) what is the role of the state? We address both questions below.
Table 1: Approaches to Civil War Duration
The State
Passive
Active
Non-State Actor
Ethnic Groups
Rebel Organizations
(a) Security Dilemma (b) Political Economy
(c) Sons of the Soil
(d) Ethnic Defection
Ethnic Groups or Rebel Organizations?
Seeking to understand the surge of civil wars during the 1990s many scholars suggested
that conflicts are fought between ethnic groups. Much of this work referred to the
conflicts in Yugoslavia, the former Soviet Union, Burundi, and Rwanda. Drawing on
international relations theory, Posen (1993) explained these conflicts as the result of an
ethnic security dilemma caused by state breakdown. According to this approach, ethnic
groups engage in preemptive violence because they fear for their own survival. The
particular history of intergroup relations, but also the physical and ethnic geography are
argued to be amongst the core determinants of the security dilemma (Posen 1993; Toft
2003). The hypothesized dynamics of this approach have important implications for the
duration of such conflicts. While not all civil wars are ethnic, civil wars fought between
ethnic groups quickly become protracted and therefore endure longer than non-ethnic
civil wars (Kaufmann 1996; 1998; Rose 2000; Kaufman 2001, 2006; Horowitz 1985; van
Evera 2001). This perspective is grounded in the assertion that ethnicity is fixed thus
distinguishing it from other identity concepts. As Kaufmann explains:
5
Ethnic conflicts are disputes between communities which see themselves as
having distinct heritages, over the power relationship between the communities,
while ideological civil wars are contests between factions within the same
community over how that community should be governed. The key difference is
the flexibility of individual loyalties, which are quite fluid in ideological conflicts,
but almost completely rigid in ethnic wars (Kaufman 1996: 138).
Moreover, battles, massacres, and other forms of violence harden these identities to the
point where compromises become delegitimized (Kaufman 2006: 205). As a
consequence, continued fighting is inevitable, leading to a “spiral of escalation” that
renders these conflicts extremely difficult, or entirely impossible, to resolve without third
party intervention (Kaufman 2006). Indeed, proponents of this view go as far as claiming
that partition is the only possible solution to such conflicts (Kaufmann 1996).
While this line of research claims that ethnic wars last longer, little systematic evidence
has been provided to support this. Indeed, empirical insights from case studies are
challenged by quantitative research revealing no significant effect of ethnic indicators
such as ethno-linguistic fractionalization or ethnic polarization (Collier 2000; Fearon
2004; Cunningham 2006, 2010; Brandt et al. 2008; Cunningham et al. 2009; although see
Collier, Hoeffler and Söderbom 2004; Montalvo and Reynal Querol 2010). Thus, our
theoretical and empirical approach is motivated by the need to reconcile these qualitative
and quantitative findings.
6
The opposing view to ethnic group based approaches questions the relevance of ethnic
groups as theoretically meaningful actors in civil wars. From this perspective, rebel
organizations, rather than ethnic groups, are the appropriate unit of analysis (Sinno 2008;
Kalyvas 2008). An important argument in favor of this view is that rebel organizations
are always present in civil wars, ethnic or not (Cunningham et al. 2009). According to
one strand of this approach, fighting in civil war is driven by incentives to secure private
gains. Such insurgencies are most likely to emerge and endure under conditions of state
weakness allowing rebel organizations to sustain successful operations (c.f. Fearon and
Laitin 2003; Collier and Hoeffler 2004). More generally, while some scholars opt for the
more neutral label of ‘rebel organizations’ (e.g. Kalyvas 2006), others are more
subjective when referring to the rebels as ‘greedy bandits’ (e.g. Collier and Hoeffler
2004), or equating them with ‘criminals’, ‘thugs’, or ‘warlord gangs’ (Mueller 2003). The
tacit nature of rebel organizations has important theoretical implications for how quickly
conflicts can be resolved. For example, Collier, Hoeffler and Söderbom (2004) argue that
the presence of looting opportunities prolongs conflicts, since rebel revenues are high and
recruitment costs are low. Presumably these conditions for “doing well out of war”
(Collier 2000) are found in the presence of lootable resources, such as narcotics,
gemstones or oil, and where effective state control is largely absent (see also Buhaug et
al. 2009; Fearon 2004).
However, Collier, Hoeffler and Söderbom (2004) also find that a moderate degree of
ethnic diversity is associated with long durations, which they interpret as facilitating
cohesion on the side of the rebels. What is not supported by the empirical data, the
7
authors argue, are effects of altruistic post-conflict payoffs related to its outcome, with an
explicit mention of political repression as an example. Accordingly, fighting occurs for
private rather than for collective benefits. Similarly, Mueller (2004) argues that at the
micro-level beliefs and emotions, such as hatred, are not stable enough to motivate long
fighting durations. Rather than the cause, they are the result of violence, or merely its
excuse.
This view is shared by Brubaker who advances an analytical focus on organizations
rather than groups since ethnic identities (“groupness”) become relevant merely as a
result of conflict: “Although […] perceived groupness does not necessarily reflect what is
felt and experienced by participants in an event, a compelling ex-post framing can
exercise a powerful feedback effect, shaping subsequent experience and increasing levels
of groupness” (Brubaker 2004: 16). In line with most political economy approaches,
Brubaker claims that ethnic identities are at best endogenous to conflict: “What is
represented as ethnic conflict or ethnic war—such as violence in former Yugoslavia—
may have as much or more to do with thuggery, warlordship, opportunistic looting, and
black-market profiteering than with ethnicity” (Brubaker 2004: 19). Thus, “ethnic”
warfare is simply a cover story for criminal violence and predation, an interpretation that
is in line with the dominant political explanations for the onset of such conflicts (e.g.
Fearon and Laitin 2003; Collier and Hoeffler 2004).
Others do not dismiss the effect of ethnicity in regard to the onset of conflict, but argue
that it does not clearly impact on the dynamics of fighting. For example, Kalyvas claims
8
that ethnic identities are unstable over the course of a conflict: “Even when ethnic
divisions cause the eruption of civil war in the first place, these identities do not always
remain stable and fixed during the conflict; if they do change, they may soften rather than
only harden” (Kalyvas 2008: 1045). Thus, collective and/or individual preferences and
identities are continuously reshaped during the course of a civil war, while master
cleavages are frequently undermined by local ones (Kalyvas 2006, 2007). This argument
runs directly counter the claim that ethnic identities are fixed since it implies that they
can be—and frequently are—transcended through the mechanism of ethnic defection, i.e.
fighting for ethnic “others” against members of one’s own group. Thus, while Kaufmann
(2005: 183) bolsters his key argument with the conjecture that “cross-ethnic recruitment
or defection is rare,” Kalyvas (2008) attempts to demonstrate that this view is mistaken.
We return to this argument below.
While many authors concentrate on either natural resources or ethnicity as an explanation
for civil war, others try to specify the conditions under which one or the other matters.
Weinstein (2007) presents a theory of rebel behavior in which ethnicity represents an
endowment from which rebel leaders choose to draw in the absence of more favorable
economic resources, such as foreign sponsors or natural resources. Thus, rebel
organizations are regarded as political entrepreneurs, whereas the presence of ethnic
identities—just like lootable resources—represent an exogenously given endowment that
has an effect on the organizational structure of a rebel organization (see also Beardsley
and McQuinn 2009). However, social and economic endowments have a differential
effect on the (self-)selection of fighters. In contrast to recruits motivated by personal
9
gains, fighters recruited through ethnic identities are more committed. By implication,
they should therefore be expected to fight longer.
In sum, most political economy approaches argue that ethnic identities have no
predictable or uniform effect on the dynamics of warfare, and thus on its duration.
Accordingly, it is not clear whether fighting hardens or softens identities. Since it is not
ethnic groups that fight, but simply rebel organizations. Indeed, due to the assumed
endogenous nature of ethnic identities, groups are held to be entirely irrelevant since their
presence does not yield any systematic prediction with regard to the process of warfare.
The Role of the State. One common problem pertaining to both approaches is the alleged
passiveness or absence of the state as an actor (we discuss notable exceptions below).
This realization brings us to the lower part of Table 1. Political economy approaches
focusing on rebel organizations typically argue that this type of actor engages in civil
violence when state weakness makes self-enrichment feasible. Thus, the inability of the
state to prevent violence creates a sufficient opportunity structure for rebel organizations.
Similarly, group-based approaches frequently explain the occurrence of violence with a
security dilemma that arises when the state cannot credibly provide security to groups
due to structural weakness (Posen 1996). According to this explanation, by assumption
the state is largely absent (Cederman, Wimmer and Min 2010: 88). Indeed it is assumed
that state failure provides an arena of ‘emerging anarchy’ in which such ethnic conflicts
can occur.
10
As notable exceptions, Fearon (2004) and Fearon and Laitin (2010), drawing heavily on
Weiner (1978), analyze particular conflict dynamics pertaining to a subset of ethnic
conflicts: sons of the soil conflicts (quadrant (c) in Table 1). These are described as
conflicts between a peripheral but geographically concentrated ethnic minority, the sons
of the soil, that is confronted with state-initiated migration to the minority’s perceived
homelands by a dominant ethnic group from the center. Scarce resources, such as land or
jobs, result in strong grievances and local struggles. Importantly, these grievances are
state-induced, since the migration is assumed to be at least partly orchestrated by the
government. They are likely to escalate where the state sides with migrants to appease
their support base. Because migration is path dependent and the government has a selfinterest in maintaining such policies it is unable to credibly commit to a peace agreement.
As argued by Fearon (2004), this renders the sons of the soil conflicts especially difficult
to end, thus prolonging the armed struggle.
Another rare example of active state behavior in the civil war literature is found in
Kalyvas’s (2008) account of ethnic defection, which is held as the prime argument as to
why ethnic identities should be treated as fluid, rather than fixed. It is described as
follows: “(a) the incumbent state is willing and able to recruit members of the rebellious
ethnic minority, (b) a substantial number of individuals collaborate with the a political
actor explicitly opposed to their own ethnic group, and (c) fighters and sympathizers
switch sides from ethnic rebels to the state” (Kalyvas 2008: 1050).
11
But although the theory postulates the effect of ethnicity to be empirically variable, this
variation is not random. Rather, it is the result of systematic state action. As Kalyvas
(2008: 1045) explains, “the behavioral potential of ethnicity is empirically variable … a
key determinant … is the willingness of incumbent states facing ethnic rebellion to
recruit ethnic defectors, which in turn depends on their resources.” Put differently, state
strength, in particular territorial control, is regarded as a systematic modifier of ethnic
identities; hence we locate this approach in quadrant (d) in Table 1.
In sum, the theoretical effect of ethnicity is disputed and the the subject of an ongoing
debate. Our survey of the literature shows that ethnic identities are either treated as
exogenously fixed or endogenous to conflict. Surprisingly, however, neither approach has
been tested systematically using large-n data. A crucial question thus concerns the
concrete causal mechanisms through which ethnicity may operate. This is what we
address in the next section by laying out a critique of the assumed nature of ethnic
identities.
Cognition or Motivation? Ethnicity and Nationalism: Ethnic defection represents an
interesting case in point. The defection argument rests largely on anecdotal or case-study
evidence, with systematic evidence across a large number of cases missing. Moreover,
even if ethnic defection is not as rare as argued by others (e.g. Kaufmann 2005), its
empirical rate vis-à-vis non-ethnic defection from rebel organizations remains unclear, as
does the net effect of ethnicity in the presence of defection. Thus, even if defection
occurs across both ethnic and non-ethnic lines, the relative frequencies are based on
12
conjectures. This net effect is important in light of another point emphasized by Kalyvas,
namely that ethnicity is argued to have an effect on hindering co-ethnics from free-riding
in civil wars: “If an individual’s chances of being victimized depend on a profile rather
than on his or her behavior, then shunning participation in the rebellion and free riding
may actually prove deadlier than joining it” (Kalyvas 2007: 186).1 Thus, under the very
conditions that make free-riding costly and risky (e.g. a profile), defection should also be
more difficult.2 Accepting both arguments at face value then leads to the prediction of a
positive net effect of ethnicity instead of the hypothesized non-effect.
The theoretical argument about ethnic profiles hindering free riding due to
straightforward identification by members of their own group implies that ethnic
identities are viewed not so much as identities, but more as traits, such as one’s physique
or language, which in turn facilitate the cognitive act of identifying group membership.
Such arguments are commonplace in the literature; ethnic groups are commonly
conceived of as social networks that facilitate cooperation through the threat of social
sanction (Axelrod 1984; Fearon and Laitin 1996; Habyarimiana et al. 2007). Thus, it is
the social context within which rebellion takes place that affects micro-level cooperation
by providing cognitive cues (see Lichbach 1998).
However, this fails to explain where ethnic preferences come from in the first place
(Varshney 2003). As a consequence, we conclude that much of the current debate
1
The argument is also not free from problems; for free-riding to become costly in the first place, the
organization must have overcome at least an initial collective action problem as to become powerful
enough to be able to induce costs upon defectors.
2
Lyall (2010) makes a related argument, aiming to demonstrate that co-ethnics are superior
counterinsurgents, potentially because of better “reachability”.
13
revolves around the very nature of identities. Where ethnicity is treated as fixed,
cognitive profiles are central, but preferences merely assumed as given. Where ethnicity
is treated as fluid, motivations are assumed to be endogenous to conflict dynamics.
However, this latter view tends to disregard the role of the state as the key actor shaping
ethnic identities and preferences through ethno-nationalist politics. The principle of
nationalism demands the unit of governance and the nation to be congruent (Gellner,
1983). Whereas the former is commonly conceived of as the state, the latter refers to a
community of common origin and shared historical destiny (Anderson 1991).
Accordingly, groups struggle over inclusion and exclusion from state power.
The argument is crucial. Whereas ethnic profiles can hardly be changed, ethnic identities
can be charged with grievances, but not necessarily so. Ethno-nationalism offers a
systematic origin that explains ethnic grievances as motivations to attain ethno-nationalist
representation wherever groups in power hinder other groups from access to executive
power. Thus, a more complete argument of ethnicity’s relevance for war-fighting has to
factor in the state as an explicit actor. We present such a theory below.
Theory: The Macro-Context of Micro-Recruitment
Our theory comprises all three types of actors described above: the state, ethnic groups
and rebel organizations. A basic visualization of our approach is given in Figure 1.
14
Broadly speaking, we argue that state induced ethno-nationalist policies lead to a
particular type of grievances amongst members of the affected groups. Previous research
has already demonstrated that such conditions are more likely to cause conflict onset
(Cederman et al. 2010). Our theoretical approach laid out in this section stipulates that
rebel organizations recruiting from excluded groups are staffed with highly committed
fighters that are willing to endure long periods of fighting. Thus, by focusing on the
relation between ethnic groups and rebel organizations, our theory highlights how ethnonationalist policies of exclusion affect conflict duration.
We challenge previous research which suggests that ethnic identities, understood as fixed
and rigid, can help to overcome collective action problems, since ethnic identities
increase “social cohesion on the rebel side” (Collier et al. 2004: 263) and provide strong
networks and mechanisms that sanction potential defectors (Fearon and Laitin 1996,
Habyarimana et al. 2007). Likewise, Weinstein (2007) has argued that rebel leaders can
resort to mobilizing on the basis of identity, rather than economic endowments. This line
of research would suggest that rebel organizations relying on ethnic linkages have
advantages in sustaining their fighting efforts. This implies that ethnic linkages as such
lead to longer fighting durations.
H1: Rebel organizations linked to ethnic groups fight longer.
15
Figure 1: A Theory of Fighting in Civil Wars
State
Groups
nationalism
opportunity
cost
exclusion
Organizations
political
entrepreneurs
Violence
duration
recruit,
delegate
Our theoretical point of departure is a concern brought forward by Kalyvas (2008: 1063)
who argues that the “relation [of rebel organizations] to underlying populations must be
the object of systematic theoretical and empirical investigation as opposed to mere
assumption” (see also Brubaker 2004). Whereas these authors base their argument about
the putative ex-ante irrelevance of ethnicity on the varying connection to ethnicity in
rebel organizations, we instead take their concern seriously by focusing systematically on
variation in nexus between rebel organizations and ethnic groups and conflict duration.
We begin with the assumption that rebel organizations are political entrepreneurs seeking
to mobilize or sustain forces with sufficient capacity to compete against the government
by violent means. Their goal is to challenge the government’s force monopoly, either in
the entire country or locally in some limited territory. Successfully sustaining forces is
therefore a key mechanism that differentiates short from long civil wars.
The key challenge for rebel organizations is the recruitment of sufficient people to
challenge the government. But initial recruitment is insufficient to sustain armed conflict;
rebel organizations in equal measure need to provide incentives to retain recruits over
16
longer periods of time. In other words, rebel organizations need to create incentives for
the fighters not to abandon the rebellion. This can only be achieved by rewarding fighters
through different kinds of compensation. We argue that variation in the reward structure–
time horizons in particular–explain why some organizations endure longer than others
(cf. Weinstein 2007). Here, we extend the literature by emphasizing that this reward
structure is not only shaped by economic opportunities, but also by the state imposed
ethno-political power configuration. This approach increases the causal depth of how
ethnicity matters and has specific empirical implications.
Two main strategies can be pursued to attract and sustain a sufficient number of fighters.
First, an organization may recruit opportunistic fighters, who seek short-run economic
benefits. Such recruits (“greedy bandits'') need to be paid immediately (short-run
payments), for example through rents generated by lootable resources. The availability of
short-run payments is therefore beneficial to the recruitment process, because the rebel
organization does not need to credibly promise future rewards. Even though short-run
incentives might attract more opportunistic fighters that are more likely to attack civilians
and harder to control (Weinstein, 2004), we argue that this does not lead to shorter
conflict durations (see also Buhaug et al. 2009; Collier et al. 2004; Fearon 2004; etc.).
We hypothesize that the availability of short-run incentives actually sustains the fighting
efforts of rebel organizations.
H2: Rebel organizations fighting in the presence of lootable resources exhibit longer
conflict durations.
17
Second, as an alternative strategy, rebel organizations may promise rewards conditional
on conflict outcomes. Initially, fighters may be attracted by the prospect of enjoying
political representation or better economic access once the government is defeated (longrun payments). However, the inherent difficulty of such a reward structure is that is
associated with greater uncertainty for at least two reasons. First, the rewards are
conditional on the future success of the rebel organization. Second, the rebel
organizations face a commitment problem if they rely on long-term rewards, because
rebel leaders have incentives to renege on reward promises once the government is
defeated.
If recruitment is intricately linked to uncertain future rewards, long fighting durations
should be most likely when individual opportunity costs are low. In other words, claims
about future benefits resonate particularly well in the presence of grievances. While there
are multiple scenarios under which such grievances can arise, we focus on ethnonationalist policies of the state. In such a model, challengers seek to avoid the rule
dominant ethnic groups by gaining access to the state or leaving it in favor of a new
polity or an already existing kin state (see Cederman, Wimmer and Min 2010). Ethnic
groups excluded from state power are deprived of political representation and likely to be
disadvantaged in accessing government provided goods. This implies that their status quo
is highly unsatisfactory. Therefore, we argue that individuals excluded from economic
goods or political representation are more likely to continue fighting for long periods of
time, even in the absence of short-term economic rewards, precisely because they have
less to lose to begin with.
18
More specifically, we argue that the socio-economic and ethno-political base of recruits
shapes their incentives to fight. Ethnic exclusion manifests itself in everyday life; indeed
members of excluded groups are subject to humiliation and are treated like second-class
citizens compared to other groups. Thus, claims by rebel organizations are likely to
resonate with members of excluded ethnic groups since the prospect of future benefits
outweighs the costs of fighting. This is because the members’ opportunity costs are
relatively low as they have little or no access to the political process and are
disadvantaged or even actively discriminated when it comes to redistributive policies of
the state. Therefore, members of excluded ethnic groups are more likely to continue
fighting in enduring rebel organizations.
By contrast, members of groups included in the political process enjoy political rights and
re-distributional benefits. Included group members should therefore be more satisfied
with the status quo than excluded group members. As a consequence, dissatisfied group
members are particularly likely to bear long fighting durations as their opportunity costs
are low due to their exclusion status, whereas included group members are more likely
defect, resulting in shorter fighting durations. Hence, we state our core hypothesis:
H3: Rebel organizations recruiting from and operating on behalf of excluded ethnic
groups are associated with longer fighting durations.
19
Data and Empirical Strategy
Data
Coding the group-organization nexus. We draw on a new data project that systematically
codes the link between rebel organization and ethnic groups. This dataset relates two
existing datasets: a dataset on rebel organizations (NSA) in civil wars by Cunningham et
al. (2009), and a dataset on politically relevant ethnic groups worldwide (EPR) by
Cederman et al. (2010). Thus, rather than determining whether a given conflict is ethnic
or not, we focus on the explicit linkage between rebel organizations and ethnic groups.
The logic of the dataset, which we label NSA2EPR, is depicted in Figure 2 and discussed
further below.
Figure 2: NSA2EPR. Relationship between Ethnic Groups and Rebel Organizations
20
Focusing on rebel organizations as the unit of analysis, rather than ethnic groups, has the
advantage of seamlessly relating our theoretical considerations to the empirical analysis.
Moreover, since many conflicts involve more than one rebel organization (Cunningham
2006; Cunningham et al. 2009; Metternich and Wucherpfennig 2010) we can differentiate
between organizations that do and do not pursue an ethnic agenda. Drawing on
information included in EPR, we further differentiate whether the ethnic groups within a
rebel organization are subject to state-induced exclusionary policies. We can therefore
establish the ethno-political context within which particular rebel organizations are
situated. Finally, note that the mapping is many-to-many, i.e. a single rebel organization
can share linkages with multiple ethnic groups. Similarly, a single ethnic group can be
connected to multiple rebel organizations.
Regarding the linkage between ethnic groups and rebel organizations, we focus on two
criteria. The first criterion assesses the ethnicity of the fighters. Put differently, we coded
from which ethnic groups, if any, a particular rebel organization recruits their fighters.
For such a linkage to exist, we require a significant number of the group members to
actively participate in the organization’s combat operations. While not all rebel
organizations recruit along ethnic lines, recruitment alone is insufficient because it may
be merely the result of local availability. In other words, depending on where a rebel
organization is active, agency may not be deliberate; ethnic recruitment may simply be
the result of local availability, and may have to do little with the organization’s actual
agenda. Therefore our second criterion is whether a given rebel organization publicly
announces to operate on behalf of the relevant ethnic group, i.e. pursues an interest that is
21
linked to the group’s fate. If recruitment and claim occur jointly, we code a rebel
organization as “ethnic”.
Coding Grievances: the Ethno-Political Context. We argue that much of the current
literature equates ethnicity in civil wars with rigid identities, but tends to disregard
variability in actual grievances. We also argue that ethno-nationalist policies by the state
that systematically exclude parts of the population from political representation on the
grounds of ethnicity are likely to induce such grievances (see Cederman et al. 2010).
Members of ethnic groups excluded from political representation are more likely to
exhibit strong grievances compared to members of groups that are part of the political
process at the center. It is this macro-political context within which rebel organizations
fight on behalf of ethnic groups, and which alters the individual level opportunity costs,
and thus micro-motives, of the fighters.
Fortunately, EPR contains information about the ethno-political power status of ethnic
groups. Through the linkage created by NSA2EPR we are able to integrate this
information at the level of rebel organizations. Thus, where a linkage between an ethnic
group and a rebel organization exists, we assess whether the group was excluded or
included from state power. This allows us to differentiate between ethnic rebel
organizations with and without ethno-nationalist motivated fighters against a common
baseline of rebel organizations with no ethnic linkage.
22
Coding Resources. Much of the literature on civil war duration emphasizes the
importance of lootable resources in the conflict zone as a means to finance fighting. We
rely on data by Buhaug et al. (2009) that indicate the presence of three types of resources
in the area where the conflict takes places. These resources are gemstones, petroleum and
drugs, all coded as dummy variables.
Control Variables. We also employ a set of control variables. The NSA data set provides
a series of variables on rebel organizations (Cunningham et al., 2009). The variable
Territorial Control indicates whether rebel organizations have actual territorial control
over some area in the country. Strong Central Command is a variable that indicates
whether a rebel organization has a coherent command structure. Additionally, we include
a dummy variable Legal Political Wing providing information about a potential rebel
organization’s political wing. On the country level we include a Democracy dummy
taking the value of one if a country has a Polity score equal or greater than 6.
Furthermore, we control for the GDP per capita and Population of a country (Gleditsch,
2004). Finally, we code whether the particular dyad exhibited Sons of the Soil dynamics
relying on the definition provided by Fearon (2004) and Fearon and Laitin (2010).
Method
To test our main hypotheses we estimate a series of semi-parametric hazards models in
which the dependent variable measures the fighting durations of rebel organizations. The
dyadic data set includes 290 rebel organizations in 198 conflicts between 1946 and 2005.
The unit of analysis is a dyad-day. The data includes 637,585 dyad-days aggregated to
23
1941 spells. A change in any of the time varying independent variables requires a new
spell. Out of the 290 rebel-government dyads 18 are right censored. The average fighting
duration of a rebel organization is 2207 days (about 6 years) with the median duration
being 758 days (about 2.1 years). Since our theoretical considerations do not predict any
particular functional form of the underlying baseline hazard, we estimate Cox
proportional hazards models. This leaves the duration dependency unspecified and
focuses the empirical analysis on how the covariates shift the baseline hazard.
We estimate all models using clustered standard errors to account for possible
interdependence between dyads within one conflict. Preliminary analysis revealed that
coups differ in their baseline hazard to other conflicts. Therefore, to allow for different
underlying baseline hazards we stratify all models by coups. We tested all models and the
included variables for a possible violation of the proportionality assumption. The tests
suggest that the proportionality assumption is not violated in any of our models.
Results. Cox proportional hazards models were estimated to assess the hypotheses. The
estimation results can be found in Table 2. The coefficients show the impact of the
explanatory variables on the underlying baseline hazards. Positive coefficients imply an
increase in the hazard of a conflict dyad ending and thus shorter fighting durations.
We begin with a baseline model that includes characteristics of the rebel organization,
resources in the conflict area, and country level controls. Model 1 suggests that rebel
organizations gaining territorial control are able to fight longer, while strong central
24
command structures and a legal political wing are associated with shorter conflict
durations. Natural resources in the conflict area have a conflict-prolonging effect.
Before turning to the main results, we shortly discuss the findings related to the country
level controls. Democratic countries are prone to very long lasting rebel organizations,
even though this result is possibly driven by India and Indonesia, while GDP per capita
and the population size seem not to significantly impact conflict dyad duration. This
insight holds across all estimated models.
Turning to the main results, we include our first main independent variable, which
indicates whether a rebel organization claims to fight on behalf of a political relevant
ethnic group and recruits from their members. Therefore, Model 2 investigates whether
ethnic linkages as such impact on conflict duration. Model 2 indicates that rebel
organizations linked to at least one political relevant ethnic group fight significantly
longer than rebel organization without such a link. The hazard of a conflict dyad ending
decreases by 23 percent if a rebel organization is linked to a politically relevant ethnic
group. In line with most of the literature this general ethnic effect is only marginally
significant. However, our theoretical argument suggested that it is not ethnicity per se,
but the state induced political exclusion of ethnic groups that leaves their members
willing to engage in prolonged fighting (Hypothesis 3).
25
Table 2: Main Results: Cox proportional hazards estimates
Model 1
Model 2
Model 3
Model 4
Model 5
VARIABLES
Ethnic Linkage
-0.249*
(0.131)
Ethnic Linkage with Excluded Group
Ethnic Linkage with Included Group
Territiorial Control
Strong Central Command
Legal Political Wing
Democracy
GDP per capita (log)
Population (log)
Natural Resources in Conflict Zone
-0.313**
(0.151)
0.344**
(0.136)
0.364*
(0.204)
-0.830***
(0.193)
0.094
(0.076)
-0.049
(0.049)
-0.370**
(0.163)
-0.306**
(0.155)
0.369***
(0.138)
0.366*
(0.192)
-0.816***
(0.193)
0.080
(0.078)
-0.036
(0.049)
-0.390**
(0.159)
-0.320**
(0.155)
-0.377***
(0.145)
0.272
(0.207)
-0.317**
(0.157)
0.417***
(0.143)
0.362**
(0.179)
-0.824***
(0.194)
0.089
(0.077)
-0.037
(0.049)
-0.364**
(0.155)
Sons of the Soil
-0.364**
(0.152)
0.285
(0.208)
-0.319**
(0.157)
0.408***
(0.147)
0.358**
(0.179)
-0.811***
(0.201)
0.094
(0.081)
-0.037
(0.049)
-0.360**
(0.155)
-0.085
(0.249)
Ethnic Linkage X Territorial Control
Dyads
Failed Dyads
Spells
Days at Risk
Log-likelihood
Chi2
290
290
290
272
272
272
1941
1941
1941
637585
637585
637585
-1161
-1159
-1156
54.47
66.17
73.34
Clustered standard errors in parentheses
*** p<0.01, ** p<0.05, * p<0.1
-0.411*
(0.226)
0.363***
(0.137)
0.388**
(0.191)
-0.802***
(0.192)
0.086
(0.077)
-0.037
(0.049)
-0.394**
(0.161)
0.218
(0.279)
290
272
1941
637585
-1156
76.37
290
272
1941
637585
-1159
65.92
To test Hypothesis 3 we empirically differentiate between organizations that are linked to
excluded and non-excluded political relevant ethnic groups. The baseline category
contains rebel organizations that do not have an ethnic link. Model 3 suggests strong
26
support for our main hypothesis. While rebel organizations related to non-excluded ethnic
groups are not associated with longer conflict durations, we find that rebel organizations
that claim to fight on behalf of political excluded ethnic groups, and recruit from their
members, fight significantly longer. Compared to the residual category, these rebel
organizations shift the underlying baseline hazard by 32 percent downwards, thus
significantly prolonging conflict dyad duration. The difference between rebel
organizations with an excluded and non-excluded ethnic link is roughly 60 percent.
Again this difference is highly statistically significant. Comparing our main explanatory
variable to the natural resource dummy highlights another result; While most of the
literature finds that resources and economic factors overtrump ethnic factors, our results
suggest that both explanations are important and that their substantive effects are similar.3
Alternative Explanations. An important question is whether we are merely capturing
effects that can be attributed to alternative explanations. Most importantly, our empirical
explanations could be driven by what Fearon (2004) calls the “sons of the soils”. Model 4
suggests that sons of the soil dynamics (SoS) do not change our main results even though
the standard errors are slightly larger. Moreover, in our models, the SoS variable itself
does not significantly impact rebel organization duration. Given the theoretical definition
of sons of the soil wars as conflicts involving “disadvantaged minorities” we interpret
this finding as evidence that SoS wars are merely a subset of ethnic conflicts involving
ethnic groups excluded form state power. Indeed a cross-tabulation reveals that all 37
dyads coded as SoS are linked to ethnic groups excluded from state power.
3
Preliminary results (not shown) suggest an interaction effect of natural resources and ethnic exclusion,
where the existence of both factors is associated with even longer conflict.
27
We also assess whether our results are partly capturing ethnic defection. Kalyvas (2008)
argues that ethnic defection becomes likely if the government has territorial control vis-àvis the rebel organization. Empirically, this would imply that ethnic defection is unlikely
when the rebel organization have territorial control, thus prolonging conflict. Therefore,
the effect of ethnicity should be stronger when rebels exercise territorial control, and
weaker or absent in conflicts where the rebels so not control territory. To assess this
implication we interacted Ethnic Linkage with Excluded Group with Territorial Control
(Model 5). The results reveal no significant interaction effect suggesting that we are not
merely tapping into ethnic defection.
Robustness Checks
We estimated a number of alternative models to assess the robustness of our results
(Table 3). In Model 6 we include further geographic variables that often are associated
with prolonged conflict. Our estimates demonstrate that including a term for whether the
conflict area abuts a border and the distance to the capital do not change our main results.
Additionally, we estimate a model controlling for whether the conflict takes place after
the end of the Cold War (Model 7). While civil wars have become significantly shorter
following the end of the Cold War, our main results stay robust to this model
specification.
28
Table 3: Robustness Results: Cox proportional hazards estimates
Model 6
Model 7
Model 8
-0.348**
(0.142)
0.302
(0.210)
-0.314*
(0.167)
0.403***
(0.140)
0.363**
(0.179)
-0.804***
(0.191)
0.081
(0.076)
-0.048
(0.057)
-0.325*
(0.167)
-0.033
(0.061)
-0.255
(0.196)
-0.395***
(0.141)
0.062
(0.213)
-0.270
(0.165)
0.375***
(0.144)
0.391**
(0.173)
-0.776***
(0.190)
0.059
(0.076)
-0.056
(0.057)
-0.372**
(0.153)
-0.026
(0.064)
-0.217
(0.189)
0.564***
(0.146)
-0.440***
(0.145)
0.262
(0.211)
-0.311*
(0.161)
0.429***
(0.139)
0.329*
(0.184)
-0.805***
(0.197)
0.063
(0.081)
-0.041
(0.050)
VARIABLES
Ethnic Linkage with Excluded Group
Ethnic Linkage with Included Group
Territiorial Control
Strong Central Command
Legal Political Wing
Democracy
GDP per capita (log)
Population (log)
Natural Resources in Conflict Zone
Conflict-Capital Distance (log)
Conflict Zone at Border
Post-Cold War
Drugs in Conflict Zone
Gemstones in Conflict Zone
Hydrocarbon in Conflict Zone
Dyads
Failed Dyads
Spells
Days at Risk
Log-likelihood
Chi2
290
290
272
272
1941
1941
637585
637585
-1154
-1145
76.43
82.44
Clustered standard errors in parentheses
*** p<0.01, ** p<0.05, * p<0.1
-0.192
(0.235)
-0.190
(0.184)
-0.185
(0.165)
290
272
1941
637585
-1156
74.67
29
Model 8 investigates whether any particular resource is driving the effect of natural
resources in the conflict area and whether the unpacking of natural resources has any
effect on our main estimates. The results demonstrate that only the aggregate measure of
natural resources has a significant effect and that our estimates stay robust.
In addition, we checked whether our results are robust with respect to alternative
estimation approaches. Therefore, we estimated several parametric hazards models
(Weibull, Lognormal, and Loglogistic), all of which yielded similar and significant
results. To assess whether our results are driven by particular conflicts or countries, we
re-estimated Model 3 with group-wise jackknifing of our sample by (a) conflicts and (b)
countries. Our estimated coefficients do not change and the standard errors stay small.
Competing Risks. Finally, we analyze whether the effect of ethnic exclusion of rebel
organization members is conditional on the conflict outcome. We therefore estimate five
further models that account for different conflict outcomes: agreements, victories (by
either party), government victories, rebel victories, and low activity. The results can be
found in Table 4. Interestingly, ethnic exclusion is strongly associated with victories and
low-activity, but has no effect on the likelihood of agreements. This suggests that ethnic
exclusion is significantly related to longer conflicts if parties cannot agree to a negotiated
settlement. This supports our theoretical conjecture that rebel organizations fighting on
behalf of excluded ethnic groups are generally more willing to accept longer periods of
fighting until a decisive outcome is reached. This, in turn, lends support to the
proposition that prior exclusion creates a commitment problem on the side of the
30
government, since any agreements are not necessarily credible. In addition, rebel
organizations that recruit from political non-excluded groups are associated with quick
agreements. Again this supports our theoretical ideas that higher opportunity costs due to
less strong grievances are associated with shorter duration.
Table 4: Competing Risks Results: Cox proportional hazards estimates
Agreement
Victory
Government
Victory
Rebel
Victory
Low activity
0.160
(0.295)
1.067**
(0.501)
0.151
(0.317)
0.100
(0.323)
-0.065
(0.534)
-0.793
(0.539)
0.007
(0.218)
-0.313**
(0.137)
-0.611
(0.384)
-0.782***
(0.252)
-0.095
(0.274)
-0.293
(0.253)
0.990***
(0.197)
0.469**
(0.216)
-1.056***
(0.344)
-0.072
(0.127)
-0.101
(0.076)
-0.369
(0.229)
-0.602*
(0.335)
-0.026
(0.356)
-0.005
(0.318)
0.586**
(0.284)
0.512*
(0.303)
-0.816**
(0.401)
0.085
(0.169)
-0.024
(0.105)
-0.332
(0.327)
-1.186**
(0.462)
-0.134
(0.606)
-0.573
(0.385)
1.474***
(0.341)
0.337
(0.347)
-1.696**
(0.699)
-0.332*
(0.182)
-0.231*
(0.123)
-0.422
(0.406)
-0.481*
(0.284)
-0.550
(0.646)
-0.488
(0.408)
-0.282
(0.417)
0.330
(0.319)
-0.662*
(0.346)
0.024
(0.163)
0.214*
(0.113)
0.145
(0.397)
290
290
290
56
115
66
1941
1941
1941
637585
637585
637585
-250.5
-490.9
-282.3
-233.9
-460.5
-272.3
25.55
56.96
17.67
Clustered standard errors in parentheses
*** p<0.01, ** p<0.05, * p<0.1
290
48
1941
637585
-203.3
-174.8
51.68
290
68
1941
637585
-305.6
-297.0
17.17
VARIABLES
Ethnic Linkage with Excluded Group
Ethnic Linkage with Included Group
Territiorial Control
Strong Central Command
Legal Political Wing
Democracy
GDP per capita (log)
Population (log)
Natural Resources in Conflict Zone
Dyads
Failed Dyads
Spells
Days at Risk
Log-Likelihood (0)
Log-Likelihood
Chi2
31
Conclusion and Policy Implications
In this paper we examined the role of ethnicity in the context of civil war duration.
Focusing on actors and agency in civil wars, we presented a theory that links rebel
organizations and ethnic groups and also includes the state as an active actor. In
particular, we have argued that exclusionary policies enacted by the state are likely to
influence the salience of ethno-nationalist grievances. More specifically, members of
ethnic groups which are systematically excluded from state power are characterized by
low opportunity costs and are therefore more likely to fight longer conflicts. These
fighters have less to lose in war and are therefore more willing to accept uncertain
payments related to future conflict outcomes. It is these grievances that allow rebel
organizations to recruit and fight on behalf of such groups to maintain their fighting base
for longer periods of time.
Thus, contrary to what is assumed by many scholars, we find that ethnic conflicts last
longer not because fixed individual loyalties are non-transendable and thus irresolvable.
Rather, our results point directly to institutions and policies that make such conflicts less
likely to begin with, but also help them come to an end, namely ethnic power-sharing
through inclusion. Whereas the view that fixed and rigid ethnic identities are at the heart
of such violence, grievances are by no means fixed. Indeed they are variable as a direct
function of ethno-nationalist exclusion. Representation at the political center should
32
therefore be seen as a powerful tool to alleviate grievances, and thereby shorten armed
conflicts.
Theoretically, we believe that our approach is not only more complete, since it covers a
more extensive set of actors, but also offers more causal depth since it goes beyond the
current literature by explaining variation in the level of grievances as the result of state
action. Our empirical results provide strong support for the argument that ethnicity only
impacts on conflict duration if members of ethnic groups are excluded from political
power. If rebel organizations are linked to these excluded ethnic groups, they fight
significantly longer. Therefore, it is not ethnicity as such but ethno-nationalist policies
that drive conflict duration.
33
Bibliography
Anderson, Benedict. 1996. Imagined communities: Reflections on the origin and spread
of nationalism. Revised ed. London: Verso.
Axelrod, R. 1984. The Evolution of Cooperation. New York: Basic Books.
Beardsley, Kyle, and Brian McQuinn. 2009. "Rebel Groups as Predatory Organizations:
The Political Effects of the 2004 Tsunami in Indonesia and Sri Lanka." Journal of
Conflict Resolution 53 (4):624-45.
Brandt, Patrick T., T. David Mason, Mehmet Gurses, Nicolai Petrovsky, and Dagmar
Radin. 2008. "When and How the Fighting Stops: Explaining the Duration and
Outcome of Civil Wars." Defence and Peace Economics 19 (6):415-34.
Brubaker, Rogers. 2004. Ethnicity without Groups. Cambridge: Harvard University Press.
Buhaug, Halvard, Scott Gates, and Paivi Lujala. 2009. "Geography, Rebel Capability,
and the Duration of Civil Conflict." Journal of Conflict Resolution 53 (4):544-69.
Cederman, Lars-Erik, Andreas Wimmer, and Brian Min. 2010. "Why Do Ethnic Groups
Rebel? New Data and Analysis." World Politics 62 (1):87-119.
Collier, P. 2000. "Doing Well Out of War." In Greed and Grievance: Economic Agendas
in Civil Wars, ed. M. Berdal and D. M. Malone. Boulder: Lynne Rienner.
Collier, Paul, and Anke Hoeffler. 2004. "Greed and Grievance in Civil Wars." Oxford
Economic Papers 56:663-95.
Collier, Paul, Anke Hoeffler, and Måns Söderbom. 2004. "On the Duration of Civil
War." Journal of Peace Research 41 (3):253-73.
Cunningham, David E. 2006. "Veto Players and Civil War Duration." American Journal
of Political Science 50 (4):875-92.
34
Cunningham, David E., Kristian Skrede Gleditsch, and Idean Salehyan. 2009. "It Takes
Two: A Dyadic Analysis of Civil War Duration and Outcome." Journal of
Conflict Resolution 53 (4):570-97.
Fearon, James D. 2004. "Why Do Some Civil Wars Last So Much Longer Than Others?"
Journal of Peace Research 41 (3):275-301.
Fearon, James D., and David D. Laitin. 2003. "Ethnicity, Insurgency, and Civil War."
American Political Science Review 97 (1):75-89.
Horowitz, Donald L. 1985. Ethnic Groups in Conflict. Berkeley: University of California
Press.
Kalyvas, Stathis N. 2006. The Logic of Violence in Civil War. Cambridge: Cambridge
University Press.
———. 2007. "Civil Wars." In The Oxford Handbook of Comparative Politics, ed. C.
Boix and S. C. Stokes. Oxford: Oxford University Press.
———. 2008. "Ethnic Defection in Civil War." Comparative Political Studies 41
(8):1043-68.
Kaufman, Stuart J. 1996. "Spiraling to Ethnic War: Elites, Masses, and Moscow on
Moldova's Civil War." International Security 21 (2):108-38.
———. 2001. Modern Hatreds: The Symbolic Politics of Ethnic War. Ithaca: Cornell
University Press.
———. 2006. "Escaping the Symbolic Politics Trap: Reconciliation Initiatives and
Conflict Resolution in Ethnic Wars." Journal of Peace Research 43 (2):201-18.
———. 2006. "Symbolic Politics or Rational Choice? Testing Theories of Extreme
Violence." International Security 30 (4):45-86.
35
Kaufmann, Chaim. 1996. "Possible and Impossible Solutions to Ethnic Civil Wars."
International Security 20 (4):136-75.
———. 2005. "Rational choice and progress in the study of ethnic conflict: A review
essay." Security Studies 14 (1):178-207.
Lichbach, Mark I. 1998. The rebel's dilemma. Ann Arbor: University of Michigan Press.
Metternich, Nils, and Julian Wucherpfennig. 2010. "Rebel Organization Interdependence
and Civil War Duration." Paper prepared for presentation at the International
Studies Association Annual Convention, New Orleans, 17-20 February.
Montalvo, José G, and Marta Reynal-Querol. 2010. "Ethnic polarization and the duration
of civil wars." Economics of Governance 11:11:123–43.
Mueller, John. 2003. "Policing the remnants of war." Journal of Peace Research 40
(5):507.
———. 2004. The Remnants of War. Ithaca: Cornell University Press.
Posen, Barry R. 1993. "The Security Dilemma and Ethnic Conflict." Survival 35 (1):2747.
Rose, William. 2000. "The security dilemma and ethnic conflict: Some new hypotheses."
Security Studies 9 (4):1-51.
Sambanis, Nicholas. 2004. "What Is Civil War?: Conceptual and Empirical Complexities
of an Operational Definition." Journal of Conflict Resolution 48 (6):814-58.
Sinno, Abadulkader H. 2008. Organizations at War in Afghanistan and beyond. Ithaca:
Cornell University Press.
Toft, Monica Duffy. 2003. The Geography of Ethnic Violence. Princeton: Princeton
University Press.
36
Van Evera, Stephen. 1994. "Hypotheses on nationalism and war." International Security
18 (4):5-39.
Varshney, Ashutosh. 2004. "Nationalism, ethnic conflict, and rationality." Perspectives
on Politics 1 (01):85-99.
Weiner, Myron. 1978. Sons of the Soil. Princeton: Princeton University Press.
Weinstein, Jeremy M. 2007. Inside rebellion: The politics of insurgent violence.
Cambridge: Cambridge University Press.
37