International Conflicts

Southern Political Science Association

No Shelter Here: Rebel Sanctuaries and International ConflictAuthor(s): Idean SalehyanSource: The Journal of Politics, Vol. 70, No. 1 (Jan., 2008), pp. 54-66Published by: Cambridge University Press on behalf of the Southern Political Science AssociationStable URL: http://www.jstor.org/stable/30218860 .

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No Shelter Here: Rebel Sanctuaries and International Conflict Idean Salehyan University of North Texas

Rebel groups often operate across national boundaries, increasing tensions between states and the odds of international conflict. Weak states are incapable of evicting rebels and are unwillingly drawn into international conflicts. Rival states support transnational rebels in order to undermine their opponents and substitute direct hostilities with action through proxies. These claims are tested through a quantitative analysis of militarized interstate disputes (MIDs) since 1945. Results support the claim that rebel sanctuaries across borders increase the probability of an international conflict. Other forms of assistance to rebel groups are also associated with increased hostilities.

in an interdependent world, civil wars are not simply domestic events, but have important implications for the international system as a

whole. Other states often become concerned about humanitarian crises during periods of internal conflict, experience negative externalities such as refugee flows and economic disruptions,1 and have strong preferences over the outcome of civil wars. Accord- ingly, external actors often intervene directly or indi- rectly during periods of civil conflict in order to affect their preferred outcome (Byman et al. 2001). In addition, actors involved in internal conflicts often span national boundaries. These domestic-international connections have been evident in the Great Lakes region of Africa, the Balkans, and the Caucasus, to name a few examples.

As such, there has been a great deal of research on foreign intervention in internal wars in recent years (see, e.g., Balch-Lindsay and Enterline 2000; Carment and Rowlands 1998; ElBadawi and Sambanis 2000; Meernik 1996; Regan 2000, 2002; Walter 2002). Much of this literature seeks to explain the causes of foreign intervention; others use intervention as an independent variable to explain conflict processes and outcomes such as the duration of war and/or the success of negotiated settlements. Yet, scholars have largely ignored the possibility that foreign interference in

another state's domestic conflicts-particularly on behalf of rebel groups-raises the probability of a violent international confrontation between states (but see Gleditsch and Salehyan 2007). Moreover, the relationship between direct military contests between states and indirect hostilities, through support for domestic insurgents, has not been thoroughly explored.

Another limitation of the literature on civil war intervention is that most researchers use arms transfers, economic aid, and/or troop deployments as measures of intervention-all of which are certainly important-but these forms of support do not exhaust all possibilities. Perhaps one of the most common types of foreign support for rebel groups is the provision of safe havens or sanctuaries on one's territory. Bases across national borders provide rebels with protection from repression by the government as state agents cannot easily exercise force outside of their sovereign territory.2 Extensive data collection shows that over half of all rebel groups since 1945 (55%) have conducted operations in other countries (Cunningham, Gleditsch, and Salehyan N.d.). Tensions between rebel host and home countries are likely to arise as hosts are accused of harboring political opponents and counterinsurgency operations near the international border create security externalities for neighbors. For such dyads, the combination of

1See Murdoch and Sandler (2004) and Salehyan and Gleditsch (2006).

2Empirically, Buhaug and Gates (2002) demonstrate that many civil wars take place near international boundaries, providing support for the claim that insurgents use borders as tactical tools.

The Journal of Politics, Vol. 70, No. 1, January 2008, Pp. 54-66 @ 2008 Southern Political Science Association

doi: 10.1017/S0022381607080048 ISSN 0022-3816

54



NO SHELTER HERE: REBEL SANCTUARIES AND INTERNATIONAL CONFLICT 55

foreign support for rebel organizations and geo- graphical contiguity provides the incentive and opportunity for war (Most and Starr 1989).

In this paper, I offer a new theory linking violent transnational actors to conflict between states. Inter- and intrastate conflicts are often intertwined in complex ways, and a neat dichotomy between the two is often misleading. I argue that transnational rebels in neighboring states raise the probability of international conflict; theoretically, this challenges conventional dyadic models of conflict that exclude nonstate actors and ignore the potential internationalization of "domestic" conflicts. In addition, the decision to host and support another state's rebels is examined. Weak neighboring states, which cannot prevent foreign rebels from using their territory, may be drawn into international conflicts not of their choosing. Rival neighbors will often provide sanctuary to rebel organizations in order to undermine their opponents rather than engage in direct military operations. This suggests that enemies sometimes substitute the international use of force with support for opposition groups. These claims will be examined below.

This theory sheds light on sources of tension in international politics that are not accounted for by traditional dyadic analyses of state-to-state interactions. For instance, relations between Afghanistan and Pakistan have recently soured over allegations that the latter is not serious about combating Al-Qaeda and Taliban forces on its territory. Israel invaded Lebanon in order to root out PLO bases there, and in summer 2006, again invaded to attack Hezbollah. In the Great Lakes region of Africa, Rwanda fought a war in Zaire/ DR Congo after the perpetrators of the 1994 genocide began to regroup as an insurgent force across the border. Moreover, international rivalries are often pursued through proxies. For example, long after Iran and Iraq ceased fighting one another, they continued to support and host rebel forces. Thus, transnational actors can become a source of friction between states and link inter- and intrastate conflict. Such dynamics are absent from current theories of international conflict which focus on states as actors.

The following section further develops the argument that extraterritorial rebel bases can spark hostilities between states. Providing sanctuary to rebels creates or exacerbates tensions between states~- leading to militarized disputes-and may be used as a substitute for interstate warfare between rival dyads. The third section describes the data and methods to be used in the statistical analysis. In particular, a time- series cross sectional analysis of international conflicts during the latter half of the twentieth century is

conducted using a variety of indicators and data sources. The fourth section reports the results of the statistical analysis. The final section concludes.

Transnational Rebels and Interstate Conflict

A defining feature of modern states is their monopoly on the domestic use of legitimate force. All states, regardless of their political institutions or policies, work to prevent armed challenges to their rule- states specialize in the use of coercion (Bates, Greif, and Singh 2002; Hardin 1997). Ordinarily, states pos- sess superior levels of military resources, personnel, and organization relative to potential insurgents, making rebellion a costly and risky strategy. Political opportunity theories of rebellion, therefore, have emphasized that regardless of the level of collective grievance in society, rebellion is unlikely to break out unless there are constraints on the ability of the state to exercise force and police its territory (Fearon and Laitin 2003; Herbst 2000; Lichbach 1995; Tarrow 1994; Tilly 1978). These constraints include factors such as difficult terrain (Fearon and Laitin 2003) and poorly functioning militaries (Herbst 2000).

However, there is little reason to expect that political opportunities to mobilize and sustain a rebellion are limited to the geographic area of the state. While states may enjoy a near monopoly on the use of force domestically, another key attribute of the state is territoriality (Kahler and Walter 2006), which implies that state power to regulate and monitor activities by subnational actors is largely confined to its sovereign jurisdiction.3 State boundaries are international institutions that demarcate mutually exclusive zones of political authority and are lines of military defense against foreign state aggression (Andreas 2003; Kratochwil 1986; Ruggie 1993; Starr 2006; Starr and Most 1976; Zacher 2001). Therefore, on the one hand, international borders establish areas in which the state is free to prevent subversion; on the other hand, they serve as constraints on the movement of military/police forces.

3As Krasner (1999) notes, sovereignty is never absolute. Military violations of strict Westphalian sovereignty can occur by contract or imposition. Some governments, for example, have agreed to allow foreign military bases or police forces on their territory. Forceful occupations of other states also do occur. However, military violations of sovereignty are certainly costly for the initiator as well. Transaction costs and the costs of direct military confrontation make sovereignty violations difficult for all but the most powerful states.



56 IDEAN SALEHYAN

Although state agents are largely restricted by national boundaries, transnationally organized rebel groups often conduct operations outside of the geographic limits of their target state in order to evade state repression (Salehyan 2007). The power of transnational actors lies in their ability to evade state regulation and control (Keck and Sikkink 1998; Keohane and Nye 1971; Risse-Kappen 1995), including for mobilizing dissent (Tarrow 2005).4 Multina- tional corporations, for instance, can evade taxation and regulation in one state by shifting operations to other countries. Similarly, transnational rebels can mobilize resources and support in areas beyond their target state's reach. For example, mobilization among diaspora groups and refugee communities-many of which have left because of dissatisfaction with the ruling regime-is common to many conflicts (Lischer 2005; Lyons 2006; Salehyan 2007; Zolberg, Suhkre, and Aguayo 1989). Bases, weapons stockpiles, training facilities, and other such resources abroad provide rebel groups significant protection from government forces. Holding bases in neighboring countries, moreover, will be especially important for the military operations of rebel organizations because they usually lack the ability to project force over long distances.5

While international borders are never completely inviolable, government forces are significantly con- strained in their ability to attack transnational rebels because doing so violates the sovereignty of the host state. Border violations substantially raise the costs of counterinsurgency operations. Counterinsurgency operations across national boundaries are hampered because the state lacks familiarity with the terrain and population; it risks a confrontation with the host state; and it invites international condemnation for sovereignty violations. Clearing and holding neighboring territory to prevent rebel access may also entail significant governance costs (on governance costs, see Lake 1996). Limited cross-border strikes may occur, provoking interstate tension, but rebels are sheltered from the full force of repression efforts when they have access to neighboring territory.6

Insurgent activities in neighboring states have even frustrated U.S. operations in Afghanistan and Iraq (Staniland 2005).

International Conflict

Most research on interstate conflict focuses on constraints on the use of force between pairs of countries such as democracy, trade interdependence, distance, and power ratios (see, e.g., Bennett and Stam 1998; Bremer 1992; Oneal and Russett 2001; Schneider, Barbieri, and Gleditsch 2003). For example, the democratic peace literature argues that political institutions and/or liberal norms constrain the use of force between democracies when they have a dispute (e.g., Bueno deMesquita et al. 1999; Oneal and Russett 2001; Schultz 2001), but does little to eluci- date what such disputes may be over. Thus, it is also important to consider the issues that lead states to fight, not just limitations on the use violence (see Diehl 1992; Gartzke 1998; Hensel 2001; Vasquez 1995). Usually, it is assumed that states fight one another over bilateral distributional issues such as territory and scarce resources (see, e.g., Fearon 1995; Hensel 2001; Krasner 1991). However, disputes frequently arise over matters of "domestic" politics, including the nature of the regime in power and conduct during civil wars. For example, there is a growing body of literature on how ethnic conflicts may spark international hostilities, particularly if transnational kinship ties are present (Cetinyan 2002; Davis and Moore 1997; Saideman 2001; Trumbore 2003; Woodwell 2004).

Despite growing attention to foreign intervention in civil wars (see, e.g., Regan 2000), scholars have neglected the possibility that providing assistance to rebels is especially likely to provoke a military confrontation between states. This suggests a source of conflict beyond the traditional emphasis on territory or natural resources. External bases are a form of support that is particularly likely to give rise to interstate conflict because, as opposed to finances and equipment that may be delivered over long distances, such bases are located in contiguous countries. It is well known that geographic contiguity increases the risk of armed conflict in a dyad (Bremer 1992; Most and Starr 1989). While patrons providing arms and finances to rebels may be far away and beyond the reach of the offended government, providing sanctuary on proximate territory allows international armed conflicts to arise.

There are two main reasons why a state's territory may be used as sanctuary by a transnational rebel

4Tarrow (2005) offers a useful theory of transnational opposition groups, but focuses mainly on protest movements. Here, the emphasis is on transnational insurgencies.

5Al-Qaeda presents a perhaps unique example of a nonstate violent actor that has global reach.

60n rare occasions, states may attempt to extensively enter and rid neighboring territory of rebel groups. For example, Israel invaded southern Lebanon in order to oust the PLO and Rwanda invaded the Democratic Republic of the Congo in order to defeat Hutu militias based there. These efforts proved extremely costly and drew widespread international condemnation, and so, such operations are uncommon.




force. First, the state may be too weak to fully control its territory and evict foreign fighters. Such states do not have adequate capabilities and face high opportunity costs for diverting military/police resources towards another country's rebels. Second, rival states may deliberately provide cover to rebel forces attacking their enemies. They use insurgent forces to further their foreign policy aims vis-a-vis their neighbors.

Rebel host and home countries may come into conflict with one another for a variety of reasons. First, the home state can retaliate against the host for harboring dissidents. Home countries will demand that the host state rid its territory of rebels and can threaten to use force in order to gain compliance. Sometimes, host governments do agree to limit rebel access; for example, in 1970 Jordan took actions to evict the Palestine Liberation Organization. Yet weak states may find it difficult to comply with these demands. Such states are not capable of restricting rebel activities; driving out foreign rebels may be just as costly (or even more so) as a confrontation with the offended state and weak states cannot make credible commitments to evict insurgents. Thus, these states are drawn into conflicts that are not of their choosing. Lebanon's inability to root out the PLO and Israel's subsequent invasion in 1982 seems to fit this type. Rival neighbors, by contrast, deliberately provide access to transnational rebels. These states will continue to host foreign insurgents when the benefits of creating instability in neighbors are exceeded by the potential for retaliation (for a formal treatment, see Bapat N.d.). Rival states will be discussed in greater depth below.

Second, although extensive counterinsurgency actions across the frontier are costly, limited forays and strikes on foreign soil sometimes occur. Cross- border fighting, stray fire, and "hot pursuit" raids into foreign territory are likely to provoke hostilities as the security and sovereignty of the host country are violated. For example, Venezuela and Colombia have had a series of disputes relating to Colombian counterinsurgency raids across their frontier. Third, conflict externalities-such as economic disruptions, health effects, and refugee flows (Ghobarah, Huth, and Russett 2003; Murdoch and Sandler 2004; Salehyan and Gleditsch 2006)-that negatively effect adjacent countries can spark international incidents. Finally, the rebel home country may deploy troops near the international border to fight insurgents, but such troop mobilization may be seen as threatening to neighbors who cannot be entirely certain of the intent of such actions, creating security-dilemma worries.

This discussion leads to my first hypothesis:

HI: External rebel bases in neighboring territories increase the probability of a militarized interstate dispute between rebel host and home countries.

Rival States and Substitution Effects

Strong, capable neighbors that do not support rebel aims are unlikely to become havens for transnational rebels. These states are both willing and able to restrict rebel activity. Above, it was argued that weak neighbors may not be able to effectively control their territory and prevent rebel access. They are unwillingly led into conflicts by transnational rebels because they cannot prevent access to their territory or foreign retaliation.

In other cases, rival neighbors may choose to host rebel organizations and provide support to opposition movements. Clearly, there are preexisting hostilities in such cases, but rebel support can exacerbate them. It is well known that international rivalries are responsible for a large share of international conflicts as militarized disputes frequently reoccur (see, e.g., Colaresi and Thompson 2002; Diehl and Goertz 2001; Thompson 2001). In many cases states confront their opponents with their own military resources. Yet in addition, states can undermine their international opponents by supporting insurgencies rather than directly using force. Pursuing such a policy comes with costs and benefits. International military disputes cost resources and lives and may invite the intervention of allies and international supporters. By assisting rebel organizations and providing access to their territory, states can avoid the costs of direct military engagement. These rebel groups, if successful in toppling the central government, will also govern the country after a civil war, freeing the state of governance costs. Yet states frequently have greater military resources at their disposal relative to rebel organizations, and therefore, international war may entail a greater likelihood of defeating the opponent.7 In addition, by providing support to rebels rather than relying upon their own efforts, states lose autonomy in directing the conflict. If states are considered to be principals and insurgents their agents, such a relationship may lead to considerable "agency slack."8 Thus there is a trade-off between avoiding costs and

70f course, states may not need to completely defeat their opponents; weakening them through promoting internal unrest may suffice.

8For example, Rwanda armed Laurent Kabila's rebel forces in order to oust the Mobutu Sese Seko government in Zaire, but Kabila later turned on his former backers.



58 IDEAN SALEHYAN

foreign policy autonomy. While the choice between strategies is an interesting subject itself, this will be left for future research.

There are several examples of rival governments that have sought to undermine their international opponents through providing sanctuary and support to rebels rather than state-to-state violence. After Iran and Iraq stopped fighting directly in 1988, they continued to pressure one another by supporting opposition groups. Iran provided shelter to the Supreme Council for the Islamic Revolution in Iraq while Iraq offered support and sanctuary to the Mojahedin- e-Khalq. Nicaragua and Honduras never engaged in a full-scale war with one another, but during the 1980's Honduras sought to weaken its rival through providing bases to the Contras. Pakistan has at times pursued its conflict with India over Kashmir through direct engagement and at other times through support for militants.

This suggests a possible substitution effect (on substitution, see Morgan and Palmer 2000; Most and Starr 1984). International rivals are known to be prone to violence against one another, yet they may substitute support for rebel organizations for direct state-to-state military action. Therefore, we should see a decrease in international military disputes when rival states support and shelter rebel organizations. This leads to a second hypothesis:

H2: International rivals are less likely to directly use force against one another when transnational rebel bases are located on their territory.

Note that this hypothesis is a conditional one. H1 argues that the presence of external bases independently increases the probability of conflict between states. H2 argues that for cases of rival dyads, rebel sanctuaries will be associated with fewer direct uses of force than would otherwise be expected. It is known that international rivals engage in disputes more frequently than other dyads; yet, H2 expects that the joint effect of rivalries and sanctuaries is not a simple additive one. Rather, there is an interactive effect where direct force between rivals is somewhat mitigated by the provision of rebel sanctuaries.

Data and Methods

To test these hypotheses, I conduct a statistical analysis of international conflicts during the latter half of the twentieth century. The units of analysis are dyad/years (nondirected) from 1946 to 1999 and are restricted to contiguous dyads because rebel bases,

with very few exceptions, are located in neighboring states. However, additional models, discussed below, do not impose such a restriction. For the dependent variable, international disputes, I employ a dichotomous variable from the Militarized Interstate Dispute (MID) dataset (Ghosn, Palmer, and Bremer 2004),9 which is coded "1" for category 4 or 5 MIDs, namely those that involve the actual use of force.10 Because the dependent variable is binary and collected over time (BTSCS), I employ the Beck, Katz, and Tucker (1998) event-history method by including a count of peace years among states and three cubic smoothing splines on the right-hand side." Accordingly, only the initial year of conflict, or onset, is recorded and ongoing years are excluded from the analysis.

The main independent variable of interest is a dichotomous indicator coded "1" if at least one state in the dyad is hosting rebels from the other state.12 Data on external bases was collected by first identifying the rebel groups listed in the Uppsala University/ International Peace Research Institute, Oslo Armed Conflicts Dataset (Gleditsch et al. 2002). Over 300 rebel organizations are listed in this data, and a variety of primary and secondary sources were con- sulted to determine if the rebels had a presence in external territory, and if so, in which countries (Cunningham, Gleditsch, and Salehyan N.d.). Over half, or 55%, of these rebel organizations had some or extensive presence in other states,13 indicating that transnational rebellion is a widespread phenomenon.

Secondly, a variable for international rivalry is included. This variable comes from William R. Thompson's (2001) dataset on international rivalries and is coded "1" for rivals (and "0" otherwise). This

9In alternative models, I use the International Crisis Behavior data (see Brecher, Wilkenfeld, and Moser 1988) as the dependent variable. Results are substantively the same and are available in an online appendix.

'1The MID data is a 0 to 5 variable that ranges from no hostility to full-blown war. A dichotomous variable for category 4 and 5 MIDs has become standard in the literature. In an alternative specification, I run an ordered logit model on the full range of the MID data. The main findings are unchanged with this model and are reported in an online appendix.

1"In the results section, below, the cubic splines are not reported in the regression tables.

12A variable for mutual support for rebels was also considered. Results remain unchanged with its inclusion.

13In the original data, this is a three-part measure for no, some, and extensive presence in other states. "Some" presence refers to limited or sporadic use of external territory, while "extensive" presence indicates major operations in other countries for a sustained period of time. The indicator used here is coded "1" for either level of external presence, though results do not change when only extensive presence is used.




data is based upon foreign policy histories between states and belligerent public statements in addition to acts of aggression. It differs from other datasets in that it is not based upon the frequency of MIDs or a minimum dispute duration. This coding is particularly attractive, given the hypothesis that rebel support is a substitute for MIDs in cases of rivalry. To test Hypothesis 2, an interaction term between external bases and rivalries is included. Since both of these variables are dichotomous (0, 1), this interaction term takes the value of 1 for cases in which both external bases and rivalries are present.

In addition to foreign sanctuaries used by transnational rebels-the main focus of this study-other forms of support to opposition groups may also be important to consider. Scholars have focused on transfers of arms and resources to rebels, and such assistance may also increase conflict behavior between states. For comparison purposes, in alternative models I include data compiled by Regan (2000) on external intervention in civil war. This is a dichotomous indicator coded "1" for cases where third parties provided military or economic assistance to rebel organizations. This was also interacted with the rival state variable to test the substitution hypothesis. A finding that other forms of support to rebels also increase conflict behavior would serve as a useful extension of the theory. Foreign support through direct transfers is somewhat different from external bases because it is a voluntary choice by the patron and is necessarily given by states that do not support the status quo regime, while passive sanctuaries may exist in weak states; also, resources can be given by distant countries while neighbors are needed for sanctuary.

Several control variables were added to the analysis. First, power ratios may affect the likelihood of conflict, as weak countries should be unlikely to confront very powerful states. The power ratio variable included here is taken from the Correlates of War's (COW) Composite Index of National Capabilities (CINC) and is the natural logarithm of the stronger party's CINC score divided by the sum of the two nations' CINCs.14 The CINC index is based upon military personnel, military expenditures, economic production, and population data. Second, alliance data, also from the COW project, was included (Singer, Bremer, and Stuckley 1972). This

is a dichotomous indicator coded "1" if the members of the dyad are part of a mutual defense pact.'" Finally, data from the Polity project was included to control for dyadic democracy; democracies are expected to be less likely to fight one another. The Polity index is a 21-point scale from -10 to 10, which includes information on institutional characteristics of the regime (Jaggers and Gurr 1995). The Polity score of the least democratic state in the dyad was included to test the democratic peace hypothesis.

To check the results against a well-established model of international war, I also replicate the results reported in Oneal and Russett (2001). This model specification includes information on all dyads, contiguous or not, from 1946 to 1991.16 As above, the dependent variable is a dummy variable for category 4 and 5 disputes. The variables in this model include the "liberal peace triad": dyadic democracy, bilateral trade, and joint membership in international organizations. Additional variables include the dyadic power ratio, alliances," distance, contiguity, and whether both states are minor powers (see Russett and Oneal for a full description of variables used). These models were also estimated using the Beck, Katz, and Tucker (1998) method for BTSCS data. All models employ robust standard errors clustered by dyad to account for additional nonindependence of observations.

Results

Table 1 reports the results using contiguous dyads. The first model includes the variable for external bases by itself, while model 2 also includes the rivals x base interaction. Model 3 compares these results with Patrick Regan's coding of foreign intervention on behalf of rebel groups. Except for defense pact in Model 3, the control variables do not reach statistical significance at conventional levels.18 This is not surprising given that these variables predict rivalries rather well. However, since these indicators are

14As an alternative specification, I include the natural log of the stronger state's CINC divided by the weaker state's CINC. Results do not change substantially.

'SThe MID, ICB, alliance, and CINC data were generated using the EUgene software. See Bennett and Stam (2000).

16Because data on external bases is only available for the post- WWII period, the full time span of the Russett and Oneal data cannot be used.

17The R&O alliance indicator is coded "1" for any form of alliance, which is different from the defense pact indicator described above.

18As an alternative specification, I include a dummy variable coded "1" for cases where both countries have a Polity score of 6 or greater. In such models, joint democracy has a negative and significant effect on conflict, supporting the democratic peace hypothesis. I include the Polity score of the least democratic state (the "weak link") in order to be consistent with work by Russett and Oneal. In this alternative model, the findings for the main variables of interest are substantively unchanged.



60 IDEAN SALEHYAN

TABLE 1 Regression Results, Contiguous Dyads

1. Coef. (Std. Err.) 2. Coef. (Std. Err.) 3. Coef. (Std. Err.)

External Base 1.147 (0.168)* 1.672 (0.194)* Rivals X Base - -1.172 (0.257)* - Intervention (Regan) - - 0.912 (0.251)* Rivals X Intervention - - -0.389 (0.328) Rivals 1.243 (0.145)* 1.552 (0.155)* 1.365 (0.158)* Power Ratio 0.265 (0.325) 0.190 (0.312) 0.200 (0.353) Defense Pact -0.147 (0.129) -0.148 (0.126) -0.258 (0.131)* Democracy -0.016 (0.012) -0.012 (0.012) -0.010 (0.012) Peace Years 0.047 (0.047) 0.046 (0.046) 0.029 (0.044) Constant -3.371 (0.186)* -3.499 (0.195)* -3.155 (0.176)* N 10197 10197 10197 Wald chiA2 298.02 333.9 283.07

Note: Standard errors clustered on dyads Cubic splines not reported *p <.05

mainly included as controls, this should not be a major concern.

Turning to the key independent variables, the external rebel base indicator is positive and significant, providing strong evidence that rebel sanctuaries are associated with a greater likelihood of interstate conflict. Interstate rivalries are also shown to significantly increase the likelihood of an international conflict, as expected. In support of hypothesis 2, model 2 displays a statistically significant interactive effect between interstate rivalries and external bases; hence, these variables cannot be considered in isolation of one another. The individual coefficients for external bases and rivalries give the log-odds of international conflict provided that the other variable is set to 0. When both variables take on the value of 1, however, the coefficient for the interaction term must be added to base estimate; being negative, the sign on the interaction indicates a reduction in log-odds. Thus, rather than a simple additive effect- which would suggest a very high probability of conflict- the presence of both conditions reduces conflict.

Model 3 compares these results with the Regan coding of foreign intervention in support of rebels. The intervention variable is positive and significant, indicating that military and economic support for rebels is also associated with a higher likelihood of international conflict, providing additional evidence that patronage of rebel groups raises the risk of conflict. However, the interaction term, while negative, is not statistically significant.19

To illustrate this finding and help interpret the results, Figure 1 displays substantive effects on the predicted probability of MIDs using these estimates. To construct a baseline probability, the power ratio was set at its mean, defense pact and Polity were set to 0, and the number of peace years was set to five. Figure 1 then compares predicted probabilities given particular values of the main independent variables. In the absence of bases or rivalry, the predicted risk of conflict is rather low, or 2%. External bases and international rivalries independently raise the probability of conflict to roughly 10% and 9%, respectively.

The final two categories display predicted probabilities when both of these conditions are present. The simple additive effect of rivalries and international bases is quite large, raising the predicted probability of conflict to over 20%. Yet, this would be misleading as there is an interaction between the two variables. When both conditions are present, there is a moderating effect, with the predicted probability of conflict rising to about 14% rather than 20%. This indicates moderate support for the substitution hypothesis. If there were a perfect substitution, then rivals would never fight directly when using proxies. This is clearly not the case; the joint presence of both conditions still raises the likelihood of conflict beyond the singular effect, yet not as much as would be expected if there were a simple combined effect.20 The argument here is that states will typically

'19When the Regan intervention variable is included in a model along with external bases, the former loses its statistical significance while bases retain significance. These results are available in an online appendix.

20In models not shown, the effect of one-sided versus mutual rebel hosting is estimated. One-sided and two-sided rebel support both raise the probability of conflict, and there is a negative interaction with rivalries. Thus, there is little difference between one-sided and mutual rebel support.




FIGURE 1 Predicted Probabilities of Conflict

0.25

0.2

& 0.15

a No Base, Base, No Base, Base, Rival Base, Rival Non-rival Non-rival Rival (Additive Model) (Interaction)

(i.e., on average) substitute rebel support for direct hostilities against rivals: some resources are chan- neled through rebel proxies rather than directed at the state's own military efforts. In some cases, however, rebel support may complement rather than substitute international hostilities. For instance, Rwandan troops supported and fought alongside local rebels in the Democratic Republic of the Congo and benefited from the latter's local knowledge. More research is clearly needed to disentangle complex and potentially endogenous relationships between rebel patronage and international conflict.

These results are checked against Russett and Oneal's Triangulating Peace (2001) dataset in Table 2. Model 4 in Table 2 replicates the R&O results for all dyads, 1946-91, but uses the Beck, Katz, and Tucker (1998) specification for BTSCS data and includes variables for rivalry and external bases.21 As before, model 5 compares these results with the Regan coding of foreign intervention. The main R&O findings are unchanged in these models, except that trade dependence and IGO membership are not significant.

The results are robust to this alternative specification. The variables for external bases, international rivalries, and the interaction term between the two continue to be significant and behave similarly to the results above. External bases and international rivalries independently increase the risk of conflict while together they decrease conflict relative to the additive effect. Thus, both hypotheses continue to find support in this set-up. In comparison, the Regan

intervention variable is also significant, but not its interaction.

Exploring the Relationship Statistical correlations are good for identifying broad empirical patterns, but they tell us little about the causal relationship behind the findings. Correlations may indeed reflect the underlying theory, they may be spurious, or they may hold for reasons other than those identified by the theory. Above, I argued that foreign support to rebel organizations is likely to cause tensions between states. While all forms of support can lead to conflict, sanctuaries in neighboring countries are especially likely to lead to military confrontations, because proximity between rebel host and home countries allows states the opportunity to fight one another. The results demonstrate a robust correlation between external bases and interstate conflict, but is this relationship truly causal?

New MID narratives available from the Corre- lates of War project22 for the 1990s allow us to get a better sense of the issues that provoke tensions between states. These narratives give a short description of the events leading to MIDs. Table 3 lists all MIDs described in the online narratives in which at least one state was hosting the other's rebel organization (s). In other words, this approach deliberately selects cases that are coded "1" for both disputes and external bases. The narratives then allow us to ascertain whether these positive "hits" in the regression are for the reasons specified by the theory or whether the relationship is not properly explained. Therefore, the objective here is not statistical infer- ence (which was done above) but rather, to look at the underlying processes that lead from the IV to the DV.

It must be mentioned, however, that only the relationship between rebel bases and conflict will be explored. The substitution between direct fighting and support for rebels is more difficult to disentangle without extensive case analysis and will be left for future research. As can be seen, Table 3 includes several rival dyads-such as India/Pakistan and Iran/ Iraq--which have fought one another directly as well as hosted rebel organizations. Remember that the claim is not that direct interstate war and support for rebels are mutually exclusive modes of conflict, but that there is some substitution between the two. Backing rebel factions may have served to decrease the prevalence of interstate fighting in particular rival

21The basic R&O model was compared with the current models using the Bayesian Information Criterion (BIC) scores (Kass and Rafterty 1995). Comparison of BIC scores indicates strong support in favor of including variables for rivalry and external bases. 22http://cow2.1a.psu.edu (last accessed January 25, 2007)



62 IDEAN SALEHYAN

TABLE 2 Regression Results, Russett and Oneal data

4. Coef. (Std. Err.) 5. Coef. (Std. Err.)

External Base 1.384 (0.179)* Rivals X Base -1.200 (0.305)* Intervention (Regan) - 0.770 (0.284)* Rivals X Intervention - -0.296 (0.346) Rivals 1.334 (0.135)* 1.198 (0.135)* Power Ratio -0.126 (0.041)* -0.120 (0.041)* Democracy -0.039 (0.011)* -0.037 (0.011)* Trade -7.474 (11.361) -8.173 (10.969) IGO Membership -0.001 (0.004) -0.001 (0.004) Allies -0.397 (0.135)* -0.463 (0.138)* Distance -0.180 (0.062)* -0.183 (0.062)* Non-Contiguous - 1.134 (0.207)* - 1.200 (0.201)* Minor Powers -0.486 (0.186)* -0.382 (0.184)* Peace Years -0.054 (0.039) -0.061 (0.038) Constant -2.648 (0.511)* -2.505 (0.516)* N 27412 27412 Wald ChiA2 899.14 860.72

Note: Standard errors clustered on dyads Cubic splines not reported *p < .05

dyads, but this is a counterfactual claim that is difficult to substantiate. Thus, the more modest aim of this endeavor is to verify links between the presence of extraterritorial rebel bases and actual MID events.

The MID narratives overwhelming confirm that issues arising out of civil wars and rebel activities are responsible for several interstate conflicts. Table 3 demonstrates that in 83% of the cases where external bases and MIDs coincided with one another, there was in fact a relationship between the two. In only 4 of the 23 listed cases was the relationship spurious or simply coincidental. Therefore, while not a definitive test, the causal mechanisms identified above do appear to be at work in the majority of cases. While conflict histories are only available for recent MIDs, this set of cases provides preliminary evidence that the statistical relationship is in fact reflecting the theorized effects.

A few examples will serve to further underscore these connections. In MID 4124, Eritrea accused Sudan of supporting an Islamic militant movement, which was trying to overthrow President Isaias Afwerki.23 In addition, Sudan accused Eritrea of providing shelter to Sudanese rebel groups from the south. As a result, there were several military clashes

between the two governments between 1996 and 1998. At first, both governments moved troops near the international border, and in a speech given in July of 1996, the Sudanese vice president warned Eritrea not to provoke a war. On July 23, however, a Sudanese newspaper reported that the government had beaten back an Eritrean invasion force comprised of rebels supported by regular troops; subsequently, a state of emergency was declared in the Sudanese province of Kassala. Over the following months, Sudanese opposition groups, notably the Sudanese People's Liberation Army, frequently launched attacks from Eritrea, and in January of 1997, made a major advance into Sudan near the town of Dawazin. After several such attacks on Sudan, the Sudanese Information Minister stated that Eritrean support for rebel groups amounted to a declaration of war between the countries. Then, on February 26, 1998, Eritrean media sources reported that Sudan had launched air and artillery attacks on several villages in the Gologue region of Eritrea. A few days later, it was reported that Eritrean forces began shelling the Suda- nese villages of Awad, Galsa, and Hadra. Further deployment of troops to the border by both governments threatened an escalation of the conflict into a full-scale war. However, this was averted by a summit in Qatar in May of 1999, when the presidents of both countries agreed to end hostilities and resume diplo- matic relations.

23This conflict summary is supplemented by news searches from the International Boundaries News Database; http://www- ibru.dur.ac.uk/resources/newsarchive.html (accessed January 12, 2006).




TABLE 3 External Bases and MID's, Case Narratives

MID Rebels Country A Country B Year Number Involved? Notes

Myanmar Thailand 1995 4002 yes Burmese rebels operating in Thailand India Bangladesh 1995 4005 no (incidental fire) India Pakistan 1993 4007 yes Dispute over bombings by Kashmir militants Greece Turkey 1994 4040 no (costal dispute) Afghanistan Tajikistan 1993 4054 yes Afghanistan supporting forces in Tajikistan Niger Chad 1993 4067 yes Chadian border guard killed while pursuing

rebels in Niger Uganda Sudan 1994 4078 yes Both sides accuse one another of supporting

rebels Tanzania Burundi 1997 4123 yes Cross-border fight between Burundi and

refugees in Tanzania Eritrea Sudan 1996 4124 yes Each side accuses the other of supporting rebels Myanmar Thailand 1999 4138 no (territorial water dispute) Turkey Iraq 1995 4158 yes Turkey enters Iraq to attack PKK (Kurdish)

forces Congo Angola 1995 4168 no (brief border clash) DR Congo Uganda 1996 4170 yes Cross-border clashes against rebel forces in

Uganda Colombia Venezuela 1997 4172 yes Spillover from Colombia conflict, Venezuela

enters Colombia Lebanon Israel 1993 4182 yes Israel attacks Hezbollah in Lebanon and Syria Syria Israel 1993 4182 yes Israel attacks Hezbollah in Lebanon and Syria Iran Turkey 1996 4191 yes Turkey enters Iran and attacks a Kurdish village Iran Iraq 1996 4192 yes Iran enters Iraq to attack Kurdish rebel forces Colombia Venezuela 1994 4219 yes Spillover from guerilla war in Colombia Congo Angola 1997 4246 yes Angola intervenes in Congo in support of

rebels Iran Turkey 1999 4289 yes Turkey attacks Iran over PKK bases DR Congo Angola 1998 4339 yes Failed peace negotiations in DRC, Angolan

support for rebels DR Congo Uganda 1998 4339 yes Failed peace negotiations in DRC, Ugandan

support for rebels

Percent Correctly Attributed: 83%

In MID 4002, Myanmar and Thailand clashed several times over the issue of ethnic Karen rebels from Myanmar operating across the border in Thailand. These incidents took place around the Burmese village of Kawmoora and the Thai village Mae Sot, which lie directly across the border from one another. On several occasions, the Burmese government pursued rebels on the other side of the border, violating Thailand's sovereignty, and prompting a Thai military response to defend the border against further attacks. Stray Burmese shells, directed at rebels, landing on Thai territory also threatened Thailand's security, and in response, the Thai government demanded that Burmese forces stay at least five kilometers away from the border.

MID 4182 refers to a series of incidents between 1993 and 2001 in which Israel clashed with Lebanon and Syria over Hezbollah presence in these countries. Cross-border attacks by Hezbollah often provoked Israeli retaliation against forces on Lebanese and Syrian territory, which in turn provoked a response from these governments. Lebanese and Syrian troops sometimes fought alongside Hezbollah guerillas when Israel launched attacks on their soil, threatening a wider regional war. Recently, Israel again invaded Lebanon in order to attack Hezbollah in 2006. As these examples demonstrate, international conflicts frequently occur as the result of rebel activities and foreign support for insurgent organizations-thus, civil wars are often not simply domestic events but



64 IDEAN SALEHYAN

they frequently incite international tensions and military incidents.

Conclusion

This article advances a theory of conflict which explicitly ties together intrastate and international disputes and considers the role of armed transnational groups. For many cases of conflict, it may be sufficient to look at dyadic interactions among states themselves. Yet, there are often strong connections between civil and international war as rebels from one country find support and safe haven in another, and as states seek to undermine their opponents through insurgent agents. This perspective offers to significantly expand our understanding of armed conflict. First, while many studies of civil war focus on states as independent units of analysis, actors involved such conflicts often extend beyond the boundaries of the country in question. Second, transnational rebels frequently give rise to tensions between host and home countries, internationalizing "domestic" wars and blurring the distinction between modes of conflict. Third, states can use a variety of tools to harm their international opponents, including support for insurgencies, and so focusing on direct hostilities alone can be misleading. Finally, the traditional emphasis on dyadic relations-namely, rebel- government and state-to-state interactions-should be expanded to include additional actors that bridge the domestic-international divide.

Further theorizing and empirical research on the transnational sources of war is likely to produce additional interesting results. For instance, it would be worthwhile to consider dispute initiation in cases involving transnational rebels. Home countries may be targeting the host state in retaliation for rebel support and for cross-border counterinsurgency operations. Yet, rival hosts may also use rebels to weaken their international opponents in preparation for an attack. Distinguishing between mechanisms would be worthwhile. In addition, understanding a country's decision to work through proxies rather than directly confronting their international opponents is an interesting extension of this research. Finally, rebels also face a decision to seek and accept foreign assistance or rely upon their own means. This choice implies a trade-off between external funding and autonomy in directing their operations.

Understanding the interdependencies between civil and international war is also likely to significantly improve policy responses to armed conflict.

The current conflict in the Sudanese region of Darfur has spillover effects in neighboring Chad and has jeopardized regional peace and stability (see Human Rights Watch 2006). The conflict in Afghanistan involves transnational insurgents based in Pakistan and has become a major source of contention. Finally, the Iraq conflict involves outside interference by states in the region and foreign fighters passing through porous borders. Securing borders against the movement of militant groups, security cooperation between states, and regional peace initiatives may improve stability in these volatile regions.

Acknowledgments

I thank Navin Bapat, Andrew Enterline, Kristian S. Gleditsch, Havard Strand, Barbara Walter, and Michael Ward for their comments and suggestions on earlier drafts. I also thank the Center for the Study of Civil War and the International Peace Research Institute of Oslo for providing financial assistance and research facilities during the writing of this paper. I am especially indebted to Scott Gates for his assistance. Finally, I thank the JOP editor and the anonymous reviewers for their useful suggestions. Earlier versions were presented at the 2005 meeting of the American Political Science Association, Wash- ington, DC and the 2006 meeting of the Peace Science Society, Columbus, OH.

Manuscript submitted 4 October 2006 Manuscript accepted for publication 6 April 2007

References

Andreas, Peter. 2003. "Redrawing the Line: Borders and Security in the Twenty-First Century." International Security 28 (2): 78-111.

Balch-Lindsay, Dylan, and Andrew Enterline. 2000. "Killing Time: The World Politics of Civil War Duration, 1820- 1992." International Studies Quarterly. 44 (4): 615-42.

Bapat, Navin. N.d. "State Support for Insurgency and Interna- tional Conflict." Unpublished typescript. Pennsylvania State University.

Bates, Robert, Avner Greif, and Smita Singh. 2002. "Organizing Violence" Journal of Conflict Resolution 46 (5): 599-628.

Beck, Nathaniel, Jonathan Katz, and Richard Tucker. 1998. "Taking Time Seriously: Time-Series Cross-Section Analysis with a Binary Dependent Variable." American Journal of Political Science 42 (4): 1260-88.

Bennett, Scott, and Allan Stam. 1998. "The Declining Advantages of Democracy: A Combined Model of War Outcomes and Duration." Journal of Conflict Resolution 42 (3): 344-66.

Bennett, Scott, and Allan Stam. 2000. "EUGene: A Conceptual Manual." International Interactions 26 : 179-204.




Brecher, Michael, Jonathan Wilkenfeld, and Sheila Moser. 1988. Crises in the Twentieth Century: Volume I. Handbook of International Crises. Oxford: Pergamon.

Bremer, Stuart A. 1992. "Dangerous Dyads: Conditions Affecting the Likelihood of Interstate War, 1816-1965." Journal of Conflict Resolution 36 (2): 309-41.

Bueno de Mesquita, Bruce, James Morrow, Randolph Siverson, and Alastair Smith. 1999. An "Institutional Explanation of the Democratic Peace." American Political Science Review 93 (4): 791-807.

Buhaug, Halvard, and Scott Gates. 2002. "The Geography of Civil War." Journal of Peace Research 39 (4): 417-33.

Byman, Daniel, Peter Chalk, Bruce Hoffman, William Rosenau, and David Brannan. 2001. Trends in Outside Support for Insurgent Movements. Santa Monica: RAND.

Carment, David, and Dane Rowlands. 1998. "Evaluating Third- Party Intervention in Intrastate Conflict." Journal of Conlict Resolution 42 (5): 572-99.

Cetinyan, Rupen. 2002. "Ethnic Bargaining in the Shadow of Third-Party Intervention." International Organization 56 (3): 645-77.

Colaresi, Michael P., and William R. Thompson. 2002. "Hot Spots or Hot Hands? Serial Crisis Behavior, Escalating Risks, and Rivalry." Journal of Politics 64 (4): 1175-98.

Cunningham, David, Kristian Gledistch, and Idean Salehyan. N.d. Dataset on Non-State Actors in Civil Wars. University of Essex.

Davis, David, and Will Moore. 1997. "Ethnicity Matters: Trans- national Ethnic Alliances and Foreign Policy Behavior." International Studies Quarterly 41 (1): 171-84.

Diehl, Paul F. 1992. "What are they Fighting for? The Importance of Issues in International Conflict Research." Journal of Peace Research 29 : 333-44.

Diehl, Paul F., and Gary Goertz. 2001. War and Peace in Interna- tional Rivalry. Ann Arbor: University of Michigan Press.

ElBadawi, Ibrahim, and Nicholas Sambanis. 2000. "External Intervention and the Duration of Civil Wars." Unpublished Working Paper. World Bank.

Fearon, James D. 1995. "Rationalist Explanations for War." International Organization 49 (3): 379-414.

Fearon, James, and David Laitin. 2003. "Ethnicity, Insurgency, and Civil War." American Political Science Review 97 (1): 75-90.

Gartzke, Erik. 1998. "Kant We All Just Get Along? Opportunity, Willingness, and the Origins of the Democratic Peace." American Journal of Political Science 42 (1): 1-27.

Gleditsch, Kristian, and Idean Salehyan. 2007. "Civil Wars and Interstate Disputes" In Resources Governance and Civil War, ed. Magnus Oberg and Kaare Strom. London: Routledge.

Gleditsch, Nils Petter, Peter Wallensteen, Mikael Eriksson, Margareta Sollenberg, and Harvard Strand. 2002. "Armed Conflict 1946-2001: A New Dataset." Journal of Peace Research 39 (5): 615-37.

Ghobarah, Hazem, Paul Huth, and Bruce Russett. 2003. "Civil Wars Kill and Main People-Long After the Shooting Stops." American Political Science Review 97 (2): 189-202.

Ghosn, Faten, Glenn Palmer, and Stuart Bremer. 2004. "The MID3 Data Set, 1993-2001: Procedures, Coding Rules, and Description." Conflict Management and Peace Science 21 (2): 133-54.

Hardin, Russell. 1995. One for All: The Logic of Group Conflict. Princeton: Princeton University Press.

Hensel, Paul. 2001. "Contentious Issues and World Politics: The Management of Territorial Claims in the Americas, 1816- 1992." International Studies Quarterly 45 (1): 81-109.

Herbst, Jeffrey. 2000. States and Power in Africa: Comparative Lessons in Authority and Control. Princton: Princeton Uni- versity Press.

Human Rights Watch. 2006. "Violence Beyond Borders: the Human Rights Crisis in Eastern Chad." New York: Human Rights Watch.

Jaggers, Keith, and Ted R. Gurr. 1995. "Tracking Democracy's Third Wave with the Polity III Data." Journal of Peace Research 32 (4): 469-82.

Kahler, Miles, and Barbara Walter. 2006. Territoriality and Conflict in an Era of Globalization. New York: Cambridge University Press.

Kass, Robert E. and Adrian Rafterty. 1995. "Bayes Factors." Journal of the American Statistical Association. 90 (430): 773.

Keck, Margaret, and Kathryn Sikkink. 1998. Activists beyond Borders: Advocacy Networks in International Politics. Ithaca: Cornell University Press.

Keohane, Robert, and Joseph Nye. 1971. Transnational Relations and World Politics. Cambridge: Harvard University Press.

Krasner, Stephen. 1991. "Global Communications and National Power: Life on the Pareto Frontier." World Politics 43 (3): 336-66.

Krasner, Stephen. 1999. Sovereignty: Organized Hypocrisy. Prince- ton: Princeton University Press.

Kratochwil, Friedrich. 1986. "Of Systems, Boundaries, and Territoriality: an Inquiry into the Formation of the States System." World Politics 39 (1): 27-52.

Lake, David. 1996. "Anarchy, Hierarchy, and the Variety of Inter- national Relations." International Organization 50 (1): 1-33.

Lichbach, Mark I. 1995. The Rebels Dilemma. Ann Arbor: Michigan University Press.

Lischer, Sarah. 2005. Dangerous Sanctuaries: Refugee Camps, Civil War, and the Dilemmas of Humanitarian Aid. Ithaca: Cornell University Press.

Lyons, Terrence. 2006. "Diasporas and Homeland Conflict." In Territoriality and Conflict in an Era of Globalization, ed. Miles Kalher and Barbara F. Walter. Cambridge: Cambridge University Press, 111-32.

Meernik, James. 1996. "United States Military Intervention and the Promotion of Democracy." Journal of Peace Research 33 (4): 391-402.

Morgan, T. Clifton, and Glenn, Palmer. 2000. "A Model of Foreign Policy Substitutability: Selecting the Right Tools for the Job (s)." Journal of Conflict Resolution 44 (1): 11-32.

Most, Benjamin, and Harvey Starr. 1984. "International Rela- tions, Foreign Policy Substitutability, and 'Nice' Laws." World Politics 36 (3): 383-406.

Most, Benjamin, and Harvey Starr. 1989. Inquiry, Logic, and International Politics. Columbia: University of South Carolina Press.

Murdoch, James, and Todd Sandler. 2004. "Civil Wars and Economic Growth: Spatial Dispersion." American Journal of Political Science 48 (1): 138-51.

Oneal, John, and Bruce M. Russett. 2001. Triangulating Peace: Democracy, Interdependence, and International Organizations. New York: Norton.

Regan, Patrick. 2000. Civil Wars and Foreign Powers: Interventions and Intrastate Conflict. Ann Arbor: University of Michigan Press.



66 IDEAN SALEHYAN

Regan, Patrick. 2002. "Third Party Interventions and the Dura- tion of Intrastate Conflict." Journal of Conflict Resolution 46 (1): 55-73.

Risse-Kappen, Thomas. 1995. Bringing Transnational Relations Back In Non-State Actors, Domestic Structures and Interna- tional Institutions. New York: Cambridge University Press.

Ruggie, John G. 1993. "Territoriality and Beyond: Problematizing Modernity in International Relations." International Organ- ization 47 : 139-74.

Salehyan, Idean. 2007. "Transnational Rebels: Neighboring States as Sanctuary for Rebel Groups." World Politics. 59 (2): 217-42.

Salehyan, Idean, and Kristian Skrede Gleditsch. 2006. "Refugees and the Spread of Civil War." International Organization 60 (2): 335-66.

Saideman, Stephen M. 2001. The Ties That Divide: Ethnic Politics, Foreign Policy, and International Conflict. New York: Colum- bia University Press.

Schneider, Gerald, Katherine Barbeiri, and Nils Petter Gleditsch, eds. 2003.Globalization and Armed Conflict. Landham, MD: Rowman and Littlefield.

Schultz, Kenneth A. 2001. Democracy and Coercive Diplomacy. Cambridge: Cambridge University Press.

Staniland, Paul. 2005. Defeating Transnational Insurgencies: the Best Offense is a Good Fence. The Washington Quarterly 29 (1): 21-40.

Starr, Harvey. 2006. "International Borders: What They Are, What They Mean, and Why We Should Care." SAIS Review 26 (1): 3-10.

Starr, Harvey, and Benjamin Most. 1976. "The Substance and Study of Borders in International Relations Research." Inter- national Studies Quarterly . 20 (4): 581-620.

Singer, J. David, Stuart Bremer, and John Stuckey. 1972. "Capability Distribution, Uncertainty, and Major Power War." In Peace, War, and Numbers, ed. B.M. Russett. Beverly Hills: Sage, 19-48.

Tarrow, Sidney. 2005. The New Transnational Activism. Cam- bridge: Cambridge University Press.

Tarrow, Sidney. 1994. Power in Movement: Social Movements, Collective Action and Politics. New York: Cambridge Univer- sity Press.

Thompson, William R. 2001. "Identifying Rivals and Rivalries in World Politics." International Studies Quarterly 45 (4): 557-86.

Tilly, Charles. 1978. From Mobilization to Revolution. Reading, MA: Addison-Wesley.

Trumbore, Peter F. 2003. "Victims or Aggressors? Ethno-political Rebellion and Use of Force in Militarized Interstate Dis- putes." International Studies Quarterly 47 (2): 183-201.

Vasquez, John. 1995. "Why Do Neighbors Fight? Proximity, Interaction, or Territoriality." Journal of Peace Research 32 (3): 277-93.

Walter, Barbara. 2002. Committing to Peace: the Successful Reso- lution of Civil Wars. Princeton: Princeton University Press.

Woodwell, Doug. 2004. "Unwelcome Neighbors: Shared Ethnic- ity and International Conflict during the Cold War." Interna- tional Studies Quarterly 48 (1): 197-223.

Zacher, Mark. 2001. "The Territorial Integrity Norm: Interna- tional Boundaries and the Use of Force." International Organization 55 (2): 215-50.

Zolberg, Aristide, Astri Suhrke, and Sergio Aguayo. 1989. Escape From Violence: Conflict and the Refugee Crisis in the Developing World. New York: Oxford University Press.

Idean Salehyan is assistant professor of political science, University of North Texas, Denton, TX 76203.



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