1

Democracy, Territory and Armed Conflict, 1919-1995

Johann Park

Assistant Professor Department of Political Science and Public Administration

Mississippi State University johann.park@msstate.edu

Patrick James

Dornsife Dean’s Professor School of International Relations University of Southern California

patrickj@usc.edu

February, 2013

Word count: 10,554

Abstract

Democracy and territory are two of the most important factors that affect conflict and war.

Yet no research design looks directly at a possible interaction between these two variables to influence occurrence of armed conflict. This study seeks to answer the following question: how do two democracies behave when a contentious issue such as territory arises as the source of conflict between them? Results based on Militarized Interstate Dispute (MID) data from 1919 to 1995 produce the conclusion that the pacifying effect of democracy stands up for both territorial dyads and non-territorial ones in spite of the imperatives toward militarization created by territorial conflict. However, territory of high salience still appears to increase the likelihood of armed conflict between two democracies.

2

This study joins a growing literature on the triadic relationship among democracy,

territorial issues,1 and armed conflict. We aim to compare and contrast the effects of democracy

and territory and identify their interactive linkage in impacting upon international strife. The

following question provides the focal point: “is the pacifying effect of democracy muted by the

conflict-generating effect of territory and vice versa?” In contrast to extant competing claims, we

argue and find that both democracy and territory account for conflict processes, while

recognizing that one does not nullify but may condition the other’s effect to a certain degree.

Each of the preceding factors separately draws extensive scholarly attention on its own,

with the pace of research on territory in particular picking up to match that of democracy over

the last decade (Vasquez 2009; Lektzian, Prins and Souva 2010).2 Democracy, on the one hand,

is a well-established characteristic that makes any given pair of states more likely to interact

peacefully in the international system. The proposition that democracies very rarely fight each

other often is referred to as the “closest thing we have to an empirical law in international

relations” (Levy 1988:661-2). Numerous statistical studies have provided empirical evidence for

the dyadic proposition about democracy,3 not only for war but also lower levels of interstate

1 We define “issues” in line with Holsti (1991:18): “the stakes over which two or more parties contend”; see also

Diehl (1992:333): “what states choose to fight over.”

2 Research on territory is expanding to include strategic behavior on the part of adversaries in a territorial context.

Carter (2010), in an innovative treatment, establishes that a target state can be expected to take action to upgrade the

defensive viability of territory coveted by a conflict initiator. This and other expectations in the context of territorial

conflict are confirmed through data analysis and provide an example of how the range of territory-related

propositions formulated and tested in the field of conflict processes is expanding rapidly.

3 At the monadic level, however, democracies appear to be as war-prone as nondemocracies in general (Small and

Singer 1976; Maoz and Abdolali 1989; Leeds and Davis 1999; major dissenting expositions appear in Benoit 1996

and Ray 2000; Souva and Prins 2006).

3

conflict such as Militarized Interstate Disputes (MIDs) (e.g. Russett and Oneal 2001; Park

2013).4 Territory, on the other hand, is the ‘rising star’ among candidate explanations for

interstate conflict processes. Territory is regarded as a salient – maybe even the most salient –

point of departure from which states go to fight and escalate violence to higher levels (e.g.

Vasquez 1993, 2009; Hensel and Mitchell 2005; Senese and Vasquez 2008).

It should be fruitful to explore a possible connection between democracy and territory,

with the one being a most robust predictor of peace and the other being a most salient source of

conflict. Two basic questions arise: Does the dyadic democratic peace holds up even for a

difficult issue like territory? Do territorial issues produce militarized strife even for democratic

dyads?5 Recent critiques based on territorial explanations suggest that the democratic peace is

epiphenomenal to territorial issues (e.g. James, Park and Choi 2006; Gibler 2007). However,

methodological limitations undercut the ability of these studies to make definitive inferences

from the data at hand. By contrast, some proponents of the democratic peace have argued that

democracies do not fight each other over territorial issues (e.g. Lake 1992; Kacowicz 1995;

Bueno de Mesquita and Siverson 1997). This bold claim, however, has yet to be exposed to

extensive, systematic empirical testing. One explanation does not have to be at odds with the

other. Each could remain meaningful even in a context where the former is conditioned by the

4 MIDs are defined as instances in which at least one state took militarized action against another state in the form of

a threat, display or actual use of force (Jones, Bremer and Singer 1996:195).

5 Senese and Vasquez (2008:268) make the following observation: “An interesting connection with the steps-to-war

research program is whether one of the reasons democratic states do not fight each other is because they do not have

territorial disputes and tend not to use power politics to resolve the disputes they do have.” Interesting to ponder, in

that context, is a recent finding that democratic states are more than twice as likely to negotiate high salience issues

(Ellis, McLaughlin and Mitchell 2010).

4

latter, and vice versa.

Preceding caveats combine to encourage a study with the present overall objective: assess

the interactive role of democracy and territory regarding conflict processes. This present study

will look directly at a possible interaction between these two variables in relation to armed

conflict. The research design builds on efforts to assess the possible contingent effects of

democracy and contentious issues on armed conflict (Mitchell and Prins 1999; Ellis, Mitchell,

and Prins 2010; Lektzian, Prins and Souva 2010; Reed and Chiba 2010; Park and Colaresi

forthcoming). We go beyond existing studies to develop interactive hypotheses and provide

empirical analyses to test the two contrasting claims. Results based on MID data and Huth and

Allee’s (2002) territorial claim data from 1919 to 1995 produce the conclusion that the pacifying

effect of democracy stands up for both territorial dyads and nonterritorial ones in spite of the

imperatives toward militarization created by territorial conflict.

This paper will unfold as follows. The second section reviews existing studies. The third

section works through theoretical explanations vis-à-vis possible interaction between democracy

and territory to produce hypotheses. The fourth section focuses on the research design, including

empirical models, data and measurement. Data analysis appears in the fifth section. The sixth and

concluding section will discuss not only contributions and implications of the analysis but also

its limitations and related suggestions for future research.

Territorial Issues vs. the Democratic Peace

One of the reasons why democracies do not fight each other may be that such dyads do

“not have territorial disputes, and such disputes…are not…handled in a power politics fashion”

(Senese and Vasquez 2005:633). Although the connection made here is interesting, the causation

implied is ambiguous. Does a lack of territorial deputes and the dovish tendency for handling

5

conflict attributed to democracies derive from their innate democratic characteristics? Or does

the relative absence of territorial issues explain both democracy and its relative peaceful nature?

Recent participants in the conversation about the democratic peace provide analyses

pertaining to these puzzles (James, Park, and Choi 2006; Gibler 2007). These studies suggest that

the democratic peace is epiphenomenal to the lack of territorial problems or at least wanes in the

context of territorial issues. For instance, Gibler (2007) argues that democratic dyads have fewer

territorial issues and thus fewer MIDs because they are a manifestation of settled borders. In

other words, both democracy and peace are symptoms of the removal of unstable borders from

the agenda of issues between two or more neighbors. Gibler reports that (1) stable borders

increase the likelihood of democracy, (2) stable borders decrease the likelihood of military

conflict, and (3) democracy has no net independent impact on conflict controlling for the

stability of borders. Gibler (2007:529) concludes that “the democratic peace is, in fact, a stable

border peace.”

Resolving territorial issues represents a significant step away from escalating to

militarized conflict and even war (Vasquez 2009). However, it remains unclear whether

democracy is still a factor that pacifies interstate relations despite the presence of territorial

issues.

James, Park and Choi (2006) provide a finding related to that matter. Building on

Hensel’s (2001) analysis of Issue Correlates of War (ICOW) territorial claim data on the Western

Hemisphere, they investigate the relationship between and among democracy, conflict

management and territory as an issue. The results they obtain create a puzzle for the democratic

peace: in territorial claims, joint democracy shows little systematic impact on choices among

strategies to resolve those claims peacefully or violently.

6

If sound, these skeptics’ arguments and findings seem to overturn the near law-like status

of the democratic peace. However, there are reasons to have serious reservations and pursue the

matter in depth with new research.

First, Gibler (2007) conceives of territorial issues in a static and indirect fashion by

focusing on unchanging geographic features such as mountainous terrain, ethnic borders and

colonial heritage. These measures are at best “proxies… [that] do not directly measure the

mutual acceptation of an [existing] border,” as Vasquez (2009:371) points out. In this framework,

states, leaders, and citizens are characterized as incapable of acting aside from passively imposed

geographical constraints. This scheme is not only of little practical value from a social scientific

point of view but also may be unrealistic. Though affected, states can get over or coordinate on

surrounding structures that are imposed exogenously. A more direct measure must pertain to

states’ voluntary and intentional actions.

Gibler (2007:529) observes that “borders are international institutions.” Institutions are

consensually defined in the field of IR as rules, procedures, and norms designed to converge

expectations and constrain behavior (North 1981; Krasner 1983). An international institution is

“what states make of it” (Wendt 1992). States institutionalize borders by showing “clear

agreement over jurisdiction” (Simmons 2005:824).

Contiguous countries lacking a geographic demarcation have incentives to settle

boundaries because mutually accepted borders are jurisdictional institutions that produce mutual

benefits such as peace and prosperity (Keohane 1984; Simmons 2005; Vasquez 2009).

Conversely, less institutionalized borders are those over which one state often challenges the

other’s jurisdictional authority regarding a piece of territory. When disagreements over borders

arise and are unresolved, these may drastically increase external territorial threats that can mar

7

political legitimacy and economic development (Simmons 2005:827; Gibler 2007:516).

Therefore, a direct measure should be something that indicates whether an actual territorial

dispute occurs between two states. In fact, few of the seven border-related variables in Gibler’s

(2007) analysis have a consistent and robust effect across different models. It is unclear whether

the reported insignificant finding for joint democracy in the presence of the border variables is

due to the presumed causality or the inefficiency of the model inflated by the inclusion of many

irrelevant variables.

Gibler’s (2007) results may reflect several limitations in research design.6 The most

important of these include (1) omitting the main effect terms of the multiple independent

variables when interacted with the land contiguity variable in predicting MIDs and (2) leaving

out the extreme cross-sectional dependence between dyads when predicting joint democracy.

Park and Colaresi (forthcoming) provide a compelling replication analysis. Whereas most of the

border variables have inconsistent and insignificant effects on both conflict and democracy, joint

democracy remains a solid pacifier across the specifications.

Second, as James et al. (2006) suggest, contentious issues like territorial claims may

reveal nuances within a largely accepted body of evidence – the democratic peace. But their

analysis is incomplete. They are relatively silent about an explanation and mainly focus on

testing whether democratic dyads can settle territorial claims more peacefully than other

combinations of states. Their spatial domain is limited to the Western Hemisphere.7 Furthermore,

their sample is a selected one consisting of dyads already involved in territorial claims.

6 For more details, see Park and Colaresi’s (forthcoming) analysis and its online appendix.

7 When feasible, James, Park and Choi’s (2006) study should be extended over the entire globe, since their

observations and tests are limited to the Western Hemisphere. This reflected the availability of ICOW data at the

time.

8

Comparing the effects of democracy conditional upon the presence and absence of territorial

issues requires considering all interstate dyads and interacting joint democracy with territorial

claims.

The question of how democracy might interact with territory to influence conflict

processes remains open. This present study addresses the caveats in the previous research. We

employ a direct measure for territorial disputes and use appropriate interactive specifications. We

also provide both theoretical and empirical reasons why the democratic peace may or may not

hold up for territorial issues. An explanation will be derived deductively via a model of issue

specification from democratic peace theorizing. In addition, a more overarching list of territorial

claims – Huth and Allee’s (2002) territorial claim (nonmilitary) list – allows extension of the

spatial domain to the entire globe for 1919 to 1995.8 Our data analysis focuses on possible

interactions of the two most prominent factors today, territory and democracy, in relation to

international conflict.

Some proponents of the democratic peace have argued that territorial issues are not of

importance for democratic dyads. For instance, Lake (1992) argues that the absence of an

expansionist bias is manifest in inter-democratic relations because an additional piece of territory

only serves the interests of a small fraction of democratic society while possibly creating a

distortion on the entire economy. Kacowicz (1995:265), acknowledging the removal of territorial

issues as the key to peace, argues that “[democracies] are conservative powers satisfied with the

territorial status quo within and across their borders.” His explanations include (a) democratic

8 Huth and Allee (2002) refer to these territorial claims as territorial disputes (short of military actions). For present

purposes, we label them as territorial claims in order to avoid confusion with militarized disputes, our dependent

variable, listed within the MID data. This practice is consistent with other studies of territorial issues (Hensel 2001;

Senese and Vasquez 2003, 2008; James, Park and Choi 2006).

9

institutions that remove irredentist and nationalist claims and make governments strong

domestically and (b) democratic norms that promote consensus based on international law and

mutual respect. Bueno de Mesquita and Siverson (1997) make an argument that parallels Lake

(1992). Democracies concerned with the provision of public goods are less likely to use force

over territorial issues because potential gain does not benefit a sufficient proportion of domestic

constituencies.

Is there evidence for the theorized negative relationship between democracy and

territorial conflict? In the democratic peace scholarship only scant empirical attention has been

paid to this matter. An exception exists. Mitchell and Prins (1999) discover that territorial MIDs

between fully-established democracies (with a Polity score of 10) are extremely rare and even

then tend to be minor. How many fully-established democracies, however, have shared borders at

any time? Mitchell and Prins report that over 40% of MIDs involved territorial issues for

democratic dyads that include at least one democracy that is less than fully institutionalized.

What is unclear is how often territorial issues have arisen between democracies and lead to

military conflict as compared to autocratic dyads.

Huth and Allee (2002; see also Huth, Croco and Appel 2011), creators of the territorial

claim list to be used here, examine how democratic dyads settle territorial issues before reaching

a military level. They divide the conflict process into three stages. At the first (status quo) stage,

Huth and Allee’s multinomial logit models support the democratic peace. Democratic challengers

are less likely to turn to force than to call for talks. At the second (negotiation) stage, findings are

mixed. Democratic targets are more likely to make concessions in talks over disputed territory

than non-democratic targets, but democratic challengers are no more inclined to make

concessions regardless of the target’s regime type. Both democratic challengers and targets

10

appear less inclined to offer concessions when politically salient concerns with ethnic co-

nationals are present within the disputed territory. At the third (military escalation) stage, with

militarized hostility, both democratic targets and challengers are no less likely than non-

democratic challengers and targets to escalate. Although Huth and Allee reveal important conflict

patterns for democratic countries in territorial disputes, yet to be explored are possible interactive

effects for the two most important factors, democracy and territory, contingent on each other.

Like James et al. (2006), Huth and Allee (2002) select on the dyads already involved in the

claims over territory. The democratic peace may exist despite the salient presence of contentious

territorial issues. However, it is unknown whether and how much the conflict-generating effect

of territory is reduced by the democratic peace as well as whether and how much the democratic

peace is weakened by territorial issues.

Most recently, based on the Huth and Allee list, Senese and Vasquez (2008) offer a major

advancement in their authoritative exposition on the “steps-to-war”. They offer a developmental

model with two main expectations: territorial claims are more likely to produce MID onset and

territorial MIDs are more likely to result in war. These propositions are confirmed for both an

overall period of 1919-1995 and three subperiods corresponding to conventional designations of

power structure. The powerful impact of territory is preserved in the presence of all standard

control variables and through multiple statistical techniques. Democracy, however, is a control

variable in the research design (Senese and Vasquez 2008: 92, 103).

Does democracy lessen the conflict-prone nature of territorial issues and to what extent?

Conversely, do territorial issues weaken the pacific effect of democracy and to what degree? We

seek answers to these interrelated questions and will test simultaneously whether the most widely

accepted evidence of the democratic peace (i.e. two democracies are less likely to experience a

11

MID) and whether territorial conflict (i.e. territorial claims tend to produce MIDs at a greater

rate) hold up against each other at the level of militarized disputes.

Hypotheses

We propose a battery of interactive hypotheses on the triadic relationship among

democracy, territory, and armed conflict. These hypotheses are developed from existing

theorizing of the democratic peace and territorial conflict.

Democratic Peace Hypotheses

Respective democratic peace explanations may produce different or similar expectations

about the behavior of democracies when territorial issues are at stake. First, the most prevalent

explanations focus on normative and institutional features unique to democracies. Democracies

are both normatively and institutionally constrained from using force against other democracies

(Ray 1995; Russett and Oneal 2001). These constraint-based explanations of the democratic

peace do not differentiate the democratic resolution mechanism according to issue type. This

may suggest the democratic peace exists regardless of issue type and even in the presence of

territorial disagreements.

Hypothesis 1: Joint democracy will reduce the probability of MID onset in the presence of

territorial claims to a degree similar to other contexts.

Variants of the institutional democratic peace explanation are able to produce more

nuanced hypotheses with respect to salient issues such as territory.

Prominent among variants of the institutional explanation is a model that focuses on the

“informational properties” of democracy (Fearon 1994; Schultz 1999; Lektzian and Souva 2009).

12

Democratic institutions help to reveal reliable information in a dispute due to the accountability

and transparency generated by their political processes. The credible information flow between

democracies makes it easier for them to identify a settlement ex ante rather than incur the risks

and costs related to use of force. Therefore, disputes between two democracies are less inclined

to militarization. The salient nature of territorial disputes may make this pattern more apparent.

The peace-inducing effect of democracies should be strengthened as the issues under contention

get more salient. The credible information flow between democracies is a function of the general

public’s attention to international disputes and crises. Given the salience of territorial issues as

discussed later, the pacifying effect of democracy may be even more evident in contention over

territory. Territorial issues between two democracies could increase the likelihood of armed

conflict between them. Compared to autocrats, however, democrats are quite susceptible to

public scrutiny and therefore should have even less incentive to bluff and misrepresent resolve

with respect to a salient issue like territory. By contrast, for two autocracies, the inability to

generate audience costs means that the very salience of territorial issues will make such dyads

even more conflictual. This leads us to expect that the gap in conflict propensities between

democratic and non-democratic dyads will be wider for territorial disputes than nonterritorial

ones.

Hypothesis 2: Territorial claims will increase the probability of MID onset for democratic dyads

but the difference in MID onset rates between democratic dyads and the other combinations of

states will be greater in the context of territorial claims.

Finally, the selectorate model, the latest variant of the institutional explanation examined

13

here, makes an interesting point about territorial issues. According to Bueno de Mesquita, Smith,

Siverson and Morrow’s (2003:418-432) analysis of the winning coalition in a state, the smaller

its size, the more likely it becomes that war aims will focus on private goods rather than public

goods. The selectorate theory regards territorial issues as something closely associated with

private goods in contrast to policy disputes regarded as something related to public goods.

Therefore, a democracy will be much less likely to risk fighting with another democracy over

territorial issues. Bueno de Mesquita et al. (2003:413) explicitly state this expectation: democrats,

who tend to have a large winning coalition, “should not seek territory for its resources nor

strongly resist demands for revision in such territories,” since resources gained by territory do

not significantly increase the ability to maintain office through provision of public goods. By

contrast, non-democratic leaders with small coalitions can benefit from increases in state

resources caused by territorial acquisition. They can use a larger resource pool to buy and

consolidate coalition members’ loyalty, increasing their ability to hold office. Thus, the

selectorate theory produces the following hypothesis.

Hypothesis 3: Territorial claims will have little impact in increasing the probability of armed

conflict among democratic dyads and the difference in MID onset rates between democratic

dyads and the other combinations of states will be greater in the context of territorial claims.

Territorial Conflict Hypotheses

According to the territorial explanation of war, territory stands out as the most important

underlying cause of militarized disputes and war among many issues (Vasquez 1993, 2009;

Vasquez and Gibler 2001; Senese and Vasquez 2008; see also Holsti 1991 and Huth 1998). As

14

Senese and Vasquez (2003:277) state, “territorial issues are very salient to leaders and followers,

so much so that, all other factors being equal, they will be willing to incur costs and take risks on

territorial questions that they would not on other issues – such as regime or policy issues.” These

assertions are backed up by two underlying arguments. First, the biological foundation of human

territoriality predisposes humans to fight for territory (Vasquez 1993:140-141; Senese and

Vasquez 2008). Second, territory is politically salient because by nature it contains both tangible

and intangible assets that are important for national integration, security, and development

(Murphy 1990:531; Huth 2000:58-59).

In regard to the democratic peace, the territorial explanation argues that factors like

democracy are proxy causes while territory is the main cause of military conflict that may end in

war, over and above regime type (Vasquez 1993; Senese and Vasquez 2008). If people in

democratic societies become particularly attached to a piece of land, public opinion may propel

leaders towards bellicosity to recover or protect the coveted territory. Contention over such

highly salient issues leaves democratic leaders vulnerable to the prescriptions of realpolitik,

thereby creating more chances to be drawn into a security dilemma (Senese and Vasquez 2005).

This suggests that the pacifying effect of joint democracy may be reduced significantly vis-à-vis

territorial issues. Thus we derive our fourth and fifth hypotheses:

Hypothesis 4: Territorial claims will increase the rate of MID onset between two democracies.

Further, the pacifying effect of democracy may be significantly reduced to the extent that:

Hypothesis 5: Joint democracy does not decrease the probability of MID onset in the context of

15

territorial claims.

Gibler’s (2007) stable border thesis makes an even stronger case, as reviewed previously:

democracy has no independent impact on military conflict because territorial issues both explain

conflict and democracy.

Hypothesis 6: Joint democracy does not decrease the probability of MID onset controlling for

territorial issues.

Territorial issues should be a hard case (or least likely case) for the democratic peace

thesis in view of the explanation based on competing territorial claims. But some proponents

argue that democracies do not initiate fighting over territorial issues, since the stakes from those

conflicts are not large enough to distribute over a wide range of democratic constituencies

(Bueno de Mesquita et al. 2003). We suspend judgment on this. If territorial issue specification

is a difficult test, favorable results should provide strong support to the democratic peace thesis,

i.e. what Levy (2002) labels the Sinatra inference – if the democratic peace theory can make it

with territorial issues it can make it with any other issues.

Research Design

Our temporal domain spans 1919 to 1995, during which both measures for democracy

and territorial claims are available. We examine all dyads rather than only dyads with territorial

claims. The use of all dyads also enables us to not only avoid the possible problems caused by

the selected sample (Geddes 1990; Senese and Vasquez 2003) but also examine the interactive

effects of democracy and territory and assess the statistical uncertainty for such contingent

16

effects. In our main analysis, we also do not limit our evidence to only politically relevant dyads

defined as those contiguous or consisting of at least one major power because of theoretical and

empirical problems associated with a limited sample. First, nothing in the theorizing suggests

that the democratic peace and territorial conflict should be limited to this subset (Gowa 2011).

Second, the criteria for politically relevant dyads do not fully identify dyads at risk of armed

conflict (Lemke and Reed 2001; Gowa 2011). Rather, we employ major power status, contiguity

and geographic distance as independent variables rather than criteria for sample selection.

However, as a robustness check, we also examine politically relevant dyads and discuss the

results in the analysis section.

We use EUGene (v.3.2) to generate the basic template of our dataset (Bennett and Stam

2000). Our dependent variable is MID onset, coded 1 if there was a new onset of a MID in a

given dyad year (otherwise 0) according to the MID dataset (v.3.1). As Bennett and Stam

recommend, we exclude ongoing MID years and ‘joiner’ dyad years unless a new direct onset of

a MID occurs within the dyad.

We turn to discussion of variables and their measurements. We have hypothesized some

possible interactions between territory and democracy in impacting upon the likelihood of armed

conflict. TERRITORY is a dummy variable that indicates whether a dyad in a given year

experiences a territorial disagreement. To identify the dyads involved in territorial claims, we use

the list from Huth and Allee (2002). It identifies 348 distinct interstate territorial claims,

worldwide from 1919 to 1995. In some cases, the same dyads have been involved in multiple

territorial claims. Huth and Allee’s list does not include claims regarding maritime boundaries.9

9 The data set is restricted to disputes over shared land borders, shared river boundaries, claims to sovereignty over

offshore islands or islands in shared rivers, or a few military base cases that raise issues of sovereignty over territory.

17

Since our units of analysis are all dyad-years from the interstate system (N = 496,442 for 1919-

1995), we code 1 if a dyad is involved in at least one territorial claim in a given year, otherwise 0.

DEMOCRACY is also a dichotomous variable. While this dichotomy does cause a loss of

information, as will become apparent, measurement loss is minimal because the vast majority of

states are either highly democratic or autocratic. As Alvarez et al. (1996: 21-22) observe, “while

democracy can be more or less advanced, one cannot be half democratic: there is a natural zero

point.” This variable is operationalized by subtracting the Polity IV index (Marshall and Jaggers

2002) of a state’s authoritarian characteristics (i.e. 0 to -10) from its institutionalized democratic

characteristics (i.e. 0 to 10). Then, we code 1 if both states in a dyad have 7 or more as a score,

otherwise 0 (Jaggers and Gurr 1995).

Based on the standard statistical model of conflict (e.g. Bremer 1992; Russett and Oneal

2001; Senese and Vasquez 2003), six control variables are introduced that may influence states’

decisions to use force for settlement. All of the controls except for peace years are

operationalized through EUGene software.

First, we include a control for geographic influence on militarized conflict. Neighboring

countries should have more opportunities and issues over which to fight militarily. Most

importantly for this present study, neighboring countries tend to have more territorial claims and

their claims may be even more salient (Vasquez 1995; Gibler 2007). Thus we need to control for

this factor to attain the unbiased net effect of territory as well as the interactive effect with

democracy. “Contiguity” is coded 1 if two states are contiguous by land or separated by less than

150 miles of water. In order to fully account for the effect of geography, we also employ distance

between two countries. “Distance” between two states is measured as the natural logarithm of the

great circle distance in miles between the capitals of the two states (or cities for the largest

18

countries such as the US). We expect that the more distance between two countries, the less

chance they experience military conflict because of geographical constraints in exercising force

over long distance.10

Second, the effect of distance to constrain militarized options may be less for the major

powers with land, sea or air capability to exercise military power from far away. Many empirical

studies have found that major powers are more conflict-prone than minor powers (e.g. Bremer

1980). Following these studies, we employ a variable that identifies whether a dyad includes at

least one major power state (“major power”). Such a case is coded 1 and otherwise 0. We expect

that a dyad consisting of only minor powers is less likely to engage in militarized attempts.

Third, previous research also shows that, the greater the difference in capabilities

between two states, the lower the likelihood they will be involved in a MID (Kugler and Lemke

1996). Therefore, the capability ratio for each dyad is included. We use the Composite Index of

National Capability (CINC) of the COW project that averages each country’s global shares of

capabilities across six components: energy consumption, iron and steel production, military

expenditure, military personnel, total population, and urban population (Singer, Bremer, and

Stuckey 1972). We measure the relative capabilities as a natural logarithm of the higher/lower

ratio between states A and B. We call this variable “capability ratio.”

Fourth, it generally is thought that allies are less likely to fight each other because they

share common security interests (and also political and economic interests). Evidence supports

this proposition (e.g. Bremer 1992; Oneal and Russett 2001). For this reason, a dichotomous

10 Some would argue against inclusion of geographic proximity controls that could exclude most current, important

territorial claims between neighbors and produce disproportionate effects on the sample from seemingly low

salience cases and old colonial cases. We consider this point and find that excluding the geographic controls does

not alter our conclusions on either the net or interactive effects of democracy and territory.

19

variable is coded 1 for any dyad sharing an alliance (i.e. defense pact, neutrality, or entente) and

zero otherwise based on the formal alliance data set of the COW Project (Gibler and Sarkees

2004).11 This variable is labeled “alliance”.

Fifth, previous studies make the case that dyads highly subject to recurring militarization

should be controlled in testing the democratic peace against contentious issues (Rasler and

Thompson 2001; Ellis et al. 2010; Lektzian et al. 2010). We measure the number of previous

MIDs between states in a given dyad and label this as “previous MIDs”.

Sixth, and finally, since the data set is structured in the form of a cross-sectional time-

series, there may be time dependence that may compromise our hypothesis testing. Thus we opt

for the method of peace year correction to test and correct the possible temporal dependence.

However, we do not use Beck et al.’s (1998) cubic splines because of arbitrariness about setting

knots. Rather, as suggested by Carter and Signorino (2010), we use cubic polynomials of peace

years (i.e. t, t2, and t3). Carter and Signorino’s Monte Carlo study shows this method can perform

as well as cubic splines and even better if knots are misspecified. As is standard for the conflict

model (Russett and Oneal 2002; Gartzke 2007; Choi 2011; Park 2013), we employ one-year lag

structure to address the possible endogeneity between conflict and independent variables.

Results

All Dyads

Panel A of Table 1 reports descriptive statistics for our dependent and independent

variables. In Panel B, dyads are classified into four cells based on regime type and territorial

claim: 1) democratic dyads with territorial claims, 2) democratic dyads without territorial claims,

11 Following Leeds (2003), we also consider two states allied if and only if they have a mutual defense pact.

Inclusion of this alternative measure did not change the results.

20

3) non-democratic dyads with territorial claims, and 4) non-democratic dyads without territorial

claims. Each cell contains the number of dyad years falling in that category. As shown,

democratic dyads appear to have territorial claims no less frequently than non-democratic

dyads.12 Among democratic dyad years, 1.26% involve territorial disputes (466/36,896) while

0.86% of non-democratic dyadic years do so (3,952/459,547). Similarly, 10.55% of territorial

claim dyad years involve democratic dyads (466/4,418), while 7.40% of nonterritorial claim

dyad years contain democratic dyads (36,430/492,025). Panel B also provides real world

examples for each interactive combination.

[Table 1 about here]

Table 2 reports probit regression results for both net and interactive effects of

TERRITORY and DEMOCRACY on MID onset for all dyads from 1919 to 1995. Briefly, the

control variables appear to have statistically significant effects in the expected directions on MID

onset across all models. As for the net effects (Model 1), both DEMOCRACY and TERRITORY

have a significant and independent impact on MID onset. Democratic dyads are less likely to

engage in an MID than non-democratic dyads whereas territorial dyads are more likely to

experience an MID than non-territorial dyads. The pacifying effect of DEMOCRACY is

confirmed despite the presence of the direct measure of territorial issues (i.e. TERRITORY). This

finding weakens Gibler’s (2007) critique that the democracy-peace relationship observed without

considering territorial threat is spurious. [Table 2 about here] [Figure 1 about here]

The presumed contingent effects of DEMOCRACY and TERRITORY are examined in

12 This result and the subsequent findings about the effect of democracy on MIDs are consistent with Kinsella and

Russett (2002). They find the effect of democracy to be greater for preventing escalation of low level disputes into

MIDs than for the initiation of low level disputes.

21

Model 2. The multiplicative interactive term for DEMOCRACY and TERRITORY is statistically

significant with a negative sign at the 0.05 level. This suggests that the pacifying effect of

DEMOCRACY increases in the context of territorial claims,13 whereas the conflict-inducing

effect of TERRITORY decreases in the context of democratic dyads. As for DEMOCRACY, its

negative coefficient is greater for territorial dyads (-.796) than non-territorial dyads (-.386) as

described in Figure1.1.a. This heightened effect of DEMOCRACY is also apparent in terms of

predicted probabilities.14 As described in Figure 1.1.b, the vertical distance that denotes the

difference in predicted probability of conflict between democratic dyads and non-democratic

dyads is greater for territorial dyads than non-territorial dyads. Substantively, democratic dyads

are about four times less likely to experience an MID than non-democratic dyads in the absence

of territorial claims – i.e. a decrease by a factor of four. Note that DEMOCRACY decreases the

probability of MID onset by a factor of 11.3 in the presence of territorial claims.

With respect to the effect of territorial issues, which is central to the territorial

explanation, territorial issues increase the likelihood of armed conflict for non-democratic dyads.

This, however, is not the case with democratic dyads. DEMOCRACY appears to significantly

13 This finding is consistent with some of the arguments made by democratic peace proponents. Huth and Allee

(2002; see also Gartzke 1998) argue that the democratic peace is about conflict management rather than dispute

occurrence, since all the variants explain behaviors in terms of “when some disagreements occur between

democracies.” In effect, the probability of a MID per se is extremely low in the dyadic sense (Spiro 1994; King and

Zeng 2001). Thus the real pacifying effect of democracy will be conspicuous when democracies have conflicting

interests to manage over certain issues.

14 For all the analyses of predicted probabilities and relative risks, we have used CLARIFY (Tomz, Wittenberg, and

King 2003). We set all continuous control variables at their median and dummy control variables at their modal

category.

22

weaken the effect of TERRITORY. As shown in Figure 1.2.a, the estimated negative coefficient

of TERRITORY is only significant for non-democratic dyads. In terms of predicted probabilities,

the difference in predicted probability of conflict between territorial dyads and non-territorial

dyads is much larger for non-democratic dyads than for democratic dyads as described in Figure

1.2.b. Substantively, territorial claims increase the likelihood of MID onset by a factor of 7.8 for

non-democratic dyads.

In sum, the findings suggest two things: 1) the pacifying effect of joint democracy holds

regardless of the presence of territorial claims, but the effect gets stronger in a territorial context;

2) the conflict-generating effect of territorial issues holds only for non-democratic dyads. These

results support the selectorate theory hypothesis (H3) that, unlike non-democratic dyads,

democratic dyads are not likely to use force for territorial issues.

In Model 3, we control for the regime type of the claimants at the start of territorial

claims (i.e. initial democracy). Hensel, Goertz and Diehl (2000:1179) find significantly fewer

rivalry relationships than expected for pairs of states that start off as democracies. The resulting

expectation in the present context is that the existence of democracy in a dyad from the outset of

a territorial claim should have a pacifying effect. As it turns out, DEMOCRACY is statistically

significant for both non-territorial dyads with the coefficient of -.429 and p-value less than 0.001

and territorial dyads with the coefficient of -.6538276 (i.e. -.3874103 + -.2664173) and p-value

of 0.003. Yet, the interactive term (i.e. DEMOCRACY×TERRITORY) is not statistically

significant, suggesting that the pacifying effect of democracy does not meaningfully vary by the

absence and presence of a territorial claim between two states. This also suggests that the

conflict-generating effect of territorial claims does not vary by the regime type of dyads.

Territorial claims increases the likelihood of an MID both for democratic dyads and for

23

nondemocratic dyads.

The insignificant result for the interaction of DEMOCRACY and TERRITORY is

inconsistent with our previous result. However, tests do not support the specification of Model 3

that includes initial democracy. First, a Wald test result (test statistic = 0.57 with p-value of 0.45)

fails to reject the null hypothesis that the effect of initial democracy is equal to zero. This result

is consistent with the insignificant coefficient estimated for initial democracy in Model 3.

Second, the model fit statistic based on the Bayesian (BIC) information criteria strongly supports

Model 2 excluding initial democracy over Model 3 including it (see the last row in Table 2).15

Politically Relevant Dyads

Some argue for use of politically relevant dyads having a reasonable chance of

disagreements and conflicts despite the weaknesses of this alternative noted above. Yet, to

examine whether territorial issues make any change for the well-confirmed effect of joint

democracy among conflict-ridden dyads, we conduct a robustness check analysis for this subset

of dyads.16 [Table 3 about here] [Figure 2 about here]

Briefly, many results are similar to the ones reported in the previous analysis but one

important qualification occurs. In any case, the results do not suggest that the democratic peace

is bounded by or epiphenomenal to territorial issues as some critics have argued (e.g. James,

Park and Choi 2006; Gibler 2007). First, each of DEMOCRACY and TERRITORY remains an

important independent predictor of conflict controlling for the other (Model 1). Second, the

effect of DEMOCRACY is estimated to be larger for territorial dyads than non-territorial dyads

15 The lower the BIC, the better the fit. An absolute difference of over 10 in BIC is the rule of thumb for the strength

of evidence favoring one model over the other.

16 We define politically relevant dyads as those in which two states are within 400 miles of water and at least one

country holds a major power status according to the COW project’s designation.

24

(Model 2; and Figure 2.1). However, this difference in coefficient is not statistically significant

as shown in Model 2 (see also the third row in Figure 2.1), suggesting DEMOCRACY reduces

armed conflict indifferently for territorial dyads and non-territorial dyads. Similarly, the effect of

territorial claims appears to be weaker for democratic dyads than non-democratic dyads (the first

and second rows in Figure 2.2). But, estimated difference is not statistically significant (the third

row in Figure 2.2), suggesting that DEMOCRACY does not lessen the conflict-generating effect

of TERRITORY among politically relevant dyads. This may be because territorial disputes

between two countries that are politically relevant are more salient than those between

presumably irrelevant dyads. The salience of issues at stake seems to be the key to the variation

in how democracies manage those issues. We address this point in the next section.

Democracy and Issue Salience

Territorial claims do not all have equal importance (see Hensel 2001). As such, our

previous analyses found that, in the sample of all dyads, TERRITORY is not a significant

predictor of conflict for democratic dyads unlike non-democratic counterparts and that

DEMOCRACY has a larger conflict-reducing effect for territorial dyads than non-territorial

dyads. However, among politically relevant dyads, TERRITORY generates armed conflict for

democratic dyads as much as non-democratic dyads while DEMOCRACY abates conflict, to a

similar degree, for both territorial dyads and non-territorial dyads. These results seem to support

the selectorate theory rather than the information theory because the former predicts that the

more salient an issue is the less the pacific effect of DEMOCRACY becomes whereas the latter

predicts the opposite.

Notwithstanding, one can infer differently from the preceding results. Politically relevant

dyads are conflict-ridden. Many of them may have nonterritorial but salient issues. Within the

25

sample of relevant dyads, territorial dyads may not be particularly contentious as compared to

non-territorial dyads. Thus, it may not be clear if our previous results really support the

selectorate theory – democracies devalue territorial issues – over the information model –

democracy is increasingly a conflict managing (rather than disagreement-inhibiting) factor when

a salient issue arises.

It is important to consider issue salience if it is really true that territorial disputes of

democratic dyads tend to be minor as some skeptics suggest. However, two difficulties arise.

First, Huth and Allee’s (2002) dataset does not include a measure for salience, although it does

identify types of territorial claims according to whether or not economic, strategic, ethnic, or no

explicitly identified value are entailed.17 Second, even if such a measure were available it is not

easy to include salience in this present study whose aim is to assess the interactive effect of

DEMOCRACY and TERRITORY. For that purpose, the universe of our data must include dyads

without territorial claims as well as those with territorial claims. It would be ideal to categorize

all dyads into those with no issues, those with low salience issues, and those with high salience

issues. However, currently there is no such overarching data available.

Although not tailored to our present purposes, the ICOW project has collected still

17 We ran a robustness check, differentiating types of territorial claims since certain types of territorial disputes may

have more salient effect and the impact of democracy may be contingent upon certain salient types of territorial

claims. Territorial claims can be categorized as having either no identified value or having economic, strategic,

ethnic values, or some combination of those values (Huth and Allee 2002). We first assessed the net effects that

different types of territorial claims have on MIDs. Then we compared these net effects to identify which types of

territorial claims have the most effects on MIDs. Using the lincom command in Stata, we found that while all

kinds of territorial claims increase the probability of a MID, in general, none of these issues has a significantly larger

impact than the other types.

26

valuable information on three kinds of contentious issues: maritime, river, and territorial claims

and their salience (Hensel, Mitchell, Sowers and Thyne 2008). This information allows us to test

the two contrasting expectations from the information model and the selectorate theory on how

the effect of DEMOCRACY on armed conflict varies by the salience of issues at stake. Using the

ICOW claims data, we identify dyad years in which dyads are involved in territorial, river, and/or

maritime claims in our dataset with an expanded time period (1816-2001). All other dyad years

in our data are excluded from the analyses. The ICOW project identifies (a) 192 dyadic territorial

claims in the Western Hemisphere and Western Europe from 1816 to 2001; (b) 82 dyadic river

claims in the Western Hemisphere, Western Europe, and Middle East from 1900-2001; and (c)

143 dyadic maritime claims in the Western Hemisphere and Europe from 1900-2001. It is

possible that the same dyad is involved in multiple claims in a given year. In those cases, we

include only observations that have the highest salience score in a given dyad year to avoid

violating the independence assumption across observations (Bennett and Stam 2000; Park and

Colaresi forthcoming). We include ICOW’s salience index (SALIENCE) that measures the

importance of each claim on a 0-12 scale (see Hensel et al. 2008). We also create a multiplicative

interaction term for DEMOCRACY and SALIENCE (i.e. DEMOCRACY×SALIENCE) to

assess how they interact in impacting upon armed conflict.

[Table 4 about here] [Figure 3 about here]

We first estimate the net independent effects of DEMOCRACY and SALIENCE. As

expected, both measures affect the probability of MID onset significantly. Not surprisingly, the

geopolitical controls, such as contiguity, distance, major power status, and alliance, are

insignificant in this limited sample of dyads with issue claims. Since both the BIC and Wald test

prefer the reduced model without these insignificant controls, we exclude them in the interactive

27

model (i.e. Model 2). Taking these insignificant variables out of the model improves the

significance level for SALIENCE from the 0.1 to 0.05 level.

In Model 3, a significant interaction is found between DEMOCRACY and SALIENCE –

the estimated coefficient for the interaction term is 0.075 with a p-value of 0.011. The positive

coefficient indicates that the pacifying effect of DEMOCRACY decreases over the level of issue

salience. A MID is less likely to occur between two issue claimants if they are democracies

rather than autocracies, but this pacific democratic relationship ceases to be the case when their

issue is highly salient. The negative coefficient of DEMOCRACY becomes insignificant at the

salience score of 9 and even its sign reverses at 11 as captured in Figure 3.1. This result holds

also in terms of predicted probability as shown in Figure 3.3. The difference in conflict

propensity between democratic dyads and non-democratic dyads disappears when an issue

involved is highly salient. DEMOCRACY abates conflict by a factor of about 3.7 for low issue

salience (i.e. SALIENCE = 3) whereas the equivalent factorial change becomes insubstantial (a

factor of 1.25) for high issue salience (i.e. SALIENCE = 9).

Figure 3.2 describes the impact of SALIENCE conditional upon DEMOCRACY.

SALIENCE only significantly increases conflict propensity for dyads of democratic claimants

whereas it does not have a significant impact for non-democratic counterparts. For non-

democratic dyads, the negative coefficient for SALIENCE is relatively small and its 95%

confidence interval includes 0 in the first row of Figure 3.2. This result also is visible in the plot

of predicted probabilities (i.e. Figure 3.3). The dashed middle line that traces the mean

probabilities of MID for democratic dyads across the levels of SALIENCE is positively steeper

that the solid middle line for non-democratic dyads. For democratic dyads, moving from the

minimum to maximum salience score heightens the likelihood of conflict by about 13 times (i.e.

28

13 factorial change). By contrast, the equivalent change in issue salience only results in a 1.6

factorial increase in the probability of MID onset for non-democratic dyads.

Taken together, these results support the selectorate theory that democracies are no less

willing to use force against each other when the issue at stake is highly salient (Bueno de

Mesquita et al. 2003). Unlike the expectation implied by the information perspective, the

audience cost presumably heightened by high issue salience does not strengthen the pacifying

impact of democracy. Indeed, considering issue salience is important in assessing how

democracies handle their contentious issues as Ellis et al. (2010) suggest. Based on the ICOW

data sets, they find that, the more salient an issue, the more democratic dyads are likely to engage

in settlement efforts by bilateral negotiations or military means.

Conclusion

Democracy matters in international conflict processes, based on the results obtained here

for MIDs, even in the presence of territorial issues. To summarize, we found that armed conflicts

are less likely between democratic dyads than non-democratic dyads even in the presence of

territorial claims and such difference in conflict proclivities becomes wider. Yet territorial issues,

which reign supreme in the steps-to-war explanation (Vasquez 2009), do result in more MIDs

even for democratic dyads that are politically relevant. The results show the extraordinary power

of democratic institutions to influence conflict processes even under the most challenging

conditions. It is especially interesting that the pacifying effect of joint democracy is greater for

territorial disagreements in the sense that the gap in conflict propensities between democratic

dyads and non-democratic ones is wider for territorial than for non-territorial disputes. This

result should be assessed with caution in that the non-territorial dyads in our sample do not

differentiate dyads with other serious issues from those that are relatively conflict-free because of

29

data availability.

New directions for research are suggested by these interesting results in the nexus of

democracy and territory and their qualifications regarding politically relevant dyads. All of the

data analysis should be replicated when, as noted above, the ICOW dataset that attempts to

identify several outstanding issues at stake in interstate relations is complete (i.e. available on a

worldwide basis). Further tests for robustness of results are in order. For example, additional

economic variables (e.g. Mousseau 2009:55-57) could be added to the research design. Also,

probing a subset of difficult disagreements could produce results more favorable to an issue-

based approach. The presence of rivalry in one research design, for example, attenuated the

impact of joint democracy in dampening dispute escalation (Lektzian, Prins and Souva 2010:

1092, 1095). Will the democratic peace thesis, which performs so well in the present research

design, hold up under further testing that includes a wider range of issue variables and their

interactions?

Another question concerns salience and (in)tangible issues in relation to conflict

escalation and management. Further analysis of democracy and territory in combination should

take that into account. It could be revealing to probe further into how, once they are involved in

MIDs, territorial issues affect democratic dyads regarding escalation into a full-scale war (i.e.

using a research design similar to Senese (1997), Reed (2000) or Senese and Vasquez (2003)).

The same can be said about the nascent research program that brings together territory,

democracy and rivalry (Lektzian, Prins and Souva 2010).

Potential causal processes embedded in statistical findings deserve closer inspection

through case studies. This is relevant to contemporary and future conflict management as well.

For instance, what can be expected among Canada, Russia, the US and other states if climate

30

change produces new sea routes in the high Arctic? At the other end of the earth, sovereignty in

Antarctica continues to produce controversy. And at many points in between, such as Gibraltar

vis-à-vis Spain and Britain, tension either is intermittent or ongoing. Thus it would be interesting

to look at ‘deviant’ territorial claims – those that do not go to MID and inter-democratic MIDs

that do not go to war – in a case study format.

Consider the especially interesting and somewhat anomalous case of jointly democratic

Ecuador and Peru, identified by Hensel, Goertz and Diehl (2000:1186) for its MIDs in 1981,

1984, and 1991.18 These MIDs came significantly after both states had transitioned into

democracy; each scores 7 or above from 1980 to 1992 .Why did these MIDs occur in spite of

democratization? Elbow (1996:103) points to the compelling role of the “iconography of lost

territories”, particularly in Ecuador. The territorial conflict with Ecuador seemed to have gone

away with the Rio Protocol of 1942 (St. John 1998:78). Yet, according to Elbow (1996), state

and society combined in Ecuador to keep the idea of territorial revisionism alive through a focus

on perceived historical injustice from the prior settlement. A causal mechanism of this kind, it

almost goes without saying, cannot be studied with ease through a large N approach, even with

excellent data such as that of MID or ICOW. Instead, it makes sense to identify anomalies for

comparative analysis through process tracing in order to understand why unexpected events

sometimes occur, which in turn may help to verify why many other things happen as expected

vis-à-vis the interaction of democracy with territory in relation to MIDs.

In closing, it is hoped that the present study will encourage efforts to look further into the

combination of territory and democracy as key variables in the explanation of international

conflict processes.

18 For more detailed treatments of this case, see Elbow (1996), St. John (1996) and Palmer (1997).

31

References

Ai, Chunrong and Edward C. Norton. 2003. “Interaction Terms in Logit and Probit models.” Economics Letters 80(1):123-129.

Alvarez, Michael, Jose Antonio Cheibub, Fernando Limongi, and Adam Przeworski. 1996.

“Classifying Political Regimes.” Studies in Comparative International Development 31(2):3-36.

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 42:1260-1288.

Benoit, Kenneth. 1996. “Democracies Really Are More Pacific (in General): Reexamining

Regime Type and War Involvement.” Journal of Conflict Resolution 40:636-657. Berry, William. D. 1999. “Testing for Interaction in Models with Binary Dependent Variables.”

Typescript. Tallahassee: Florida State University. Berry, William. D., Jacqueline H.R. DeMeritt, and Justin Esarey, 2010. Testing for Interaction in

Binary Logit and Probit Models: Is a Product Term Essential? American Journal of Political Science 54(1):248-266.

Brambor, Thomas., William. R. Clark, and Matt Golder. 2006. “Understanding Interaction

Models: Improving Empirical Analyses.” Political Analysis 14(1):63-82. Braumoeller, B. F. 2004. “Hypothesis Testing and Multiplicative Interaction Terms.”

International Organization 58(4):807-820. Bremer, Stuart. 1980. “National Capabilities and War Proneness.” in J. David Singer (ed) The

Correlates of War II: Testing Some Realpolitik Models, New York: Free Press, 57-82. Bueno de Mesquita, Bruce, and David Lalman. 1992. War and Reason: Domestic and

International Imperatives. New Heaven: Yale University Press. Bueno de Mesquita, Bruce, and Randolph Siverson. 1997. “Institutions and the Issues of

Conflict: A Further Test.” Paper presented at the Annual Meeting of the Midewest Political Science Association, Chicago.

Bueno de Mesquita, Bruce, Alastair Smith, Randolph M. Siverson and James D. Morrow. 2003.

The Logic of Political Survival. Cambridge, MA: The MIT Press. Carter, David B. 2010. “The Strategy of Territorial Conflict.” American Journal of Political

Science 54:969-987. Carter, David B., and Curtis S. Signorino. 2010. “Back to the Future: Modeling Time

32

Dependence in Binary Data.” Political Analysis 18:271-292. Dafoe, Allan. 2011. “Statistical Critiques of the Democratic Peace: Caveat Emptor.” American

Journal of Political Science 55 (2):247-262. Diehl, Paul F. 1992. “What Are They Fighting For? The Importance of Issues in International

Conflict Research.” Journal of Peace Research 29:333-344. Dixon, William. J. 1994. “Democracy and the Peaceful Settlement of International Conflict.”

American Political Science Review:14-32. Elbow, Gary S. 1996. “Territorial Loss and National Image: The Case of Ecuador.” Yearbook:

Conference of Latin Americanist Geographers 22:93-105. Ellis, Glynn, Sara Mitchell and Brandon Prins. 2010. “How Democracies Keep the Peace:

Contextual Factors That Influence Conflict Management Strategies.” Foreign Policy Analysis 6:373-398.

Fearon, James D. 1994. “Domestic Political Audiences and the Escalation of International

Disputes.” American Political Science Review 88(3):577-92. Gartzke, Erik. 1998. “Kant We All Just Get Along? Motive, Opportunity, and the Origins of the

Democratic Peace.” American Journal of Political Science 42(1):1–27. Geddes, Barbara. 1990. “How the Cases You Choose Affect the Answers You Get: Selection Bias

in Comparative Politics.” Political Analysis 2(1):131-150. Gibler, Douglas M. 2007. “Bordering on Peace: Democracy, Territorial Issues, and Conflict.”

International Studies Quarterly 51(3):509-532. Gibler, Douglas M., and Meredith Reid Sarkees. 2004. “Measuring Alliances: The Correlates of

War Formal Interstate Alliance Dataset, 1816-2000.” Journal of Peace Research 41(2):211-22.

Gowa, Joanne. 2011. The Democratic Peace after the Cold War.” Economics & Politics

23(2):153-171. Hensel, Paul R. 2001. “Contentious Issues and World Politics: The Management of Territorial

Claims in the Americas, 1816-1992.” International Studies Quarterly 45(1):81-109. Hensel, Paul R. 1999. “Charting a Course to Conflict: Territorial Issues and Interstate Conflict,

1816-1992.” In Paul F. Diehl, ed., A Road Map to War: Territorial Dimensions of International Conflict. Nashville and London: Vanderbilt University Press.

Hensel, Paul, Gary Goertz, and Paul Diehl. 2000. “The Democratic Peace and Rivalries.”

Journal of Politics 62(4):1173-1188.

33

Hensel, Paul R., and Sara Mitchell. 2005. “Issue Indivisibility and Territorial Claims.”

GeoJournal 64: 275-285. Hensel, Paul R., Sara Mitchell, Thomas E. Sowers II and Clayton L. Thyne. 2008. “Bones of

Contention: Comparing Territorial, Maritime and River Issues.” Journal of Conflict Resolution 52:117-143.

Huth, Paul K. 2000. “Territory: Why Are Territorial Disputes between States a Central Cause of

International Conflict?” In John A. Vasquez ed., What Do We Know about War? Boston, Maryland: Rowman & Littlefield Publishers.

Huth, Paul. K. 1998. Standing Your Ground: Territorial Disputes and International Conflict:

University of Michigan Press. Huth, Paul K. and Todd L. Allee. 2002 The Democratic Peace and Territorial Conflict in the

Twentieth Century. Cambridge: Cambridge University Press. Huth, Paul K., Sarah E. Croco and Benjamin J. Appel. 2011. “Does International Law Promote

the Peaceful Settlement of International Disputes? Evidence from the Study of Territorial Conflicts since 1945.” American Political Science Review 105:415-436.

Jaggers, Keith, and Tedd Robert Gurr. 1995. “Tracking Democracy’s Third Wave with the Polity

III Data. Journal of Peace Research 32(4):469-482. James, Patrick, Johann Park, and Seung-Whan Choi. 2006. “Democracy and Conflict

Management: Territorial Claims in the Western Hemisphere Revisited.” International Studies Quarterly 50:803-817.

Jones, Daniel M., Stuart A. Bremer, and J. David Singer. 1996. “Militarized Interstate Disputes,

1816-1992: Rationale, Coding Rules, and Empirical Patterns.” Conflict Management and Peace Science 15(2):163-213.

Kacowicz, Arie. M. 1995. “Explaining Zones of Peace: Democracies as Satisfied Powers?”

Journal of Peace Research 32(3):265-276. Kinsella, David, and Bruce Russett. 2002. “Conflict Emergence and Escalation in Interactive

International Dyads.” Journal of Politics 64(4):1045-1068. King, Gary, and Langche Zeng. “Explaining Rare Events in International Relations.”

International Organization 55(3):693-715. Kugler, Jacek and Douglas Lemke. 1996. Parity and War: Evaluations and Extensions of the War

Ledger. Ann Arbor, MI: University of Michigan Press. Leeds, Brett Ashley, and David R. Davis. 1999. “Beneath the Surface: Regime Type and

34

International Interaction, 1953-78.” Journal of Conflict Resolution 36(1):5-21. Lektzian, David, Brandon C. Prins and Mark Souva. 2010. “The Effect of Rivalry and

Democracy on Militarized Inter-State Conflict Over Issue Claims in the Western Hemisphere, 1901-2000.” Unpublished Manuscript.

Lektzian, David, Brandon C. Prins and Mark Souva. 2010. “Territory, River, and Maritime

Claims in the Western Hemisphere: Regime Type, Rivalry, and MIDs from 1901 to 2000.” International Studies Quarterly 54:1073-1098.

Lektzian, David, and Mark Souva. 2009. “A Comparative Theory Test of Democratic Peace

Arguments, 1946-2000.” Journal of Peace Research 45 (5): 613-631. Lemke, Douglas, and William Reed. 2001. “The Relevance of Politically Relevant Dyads.”

Journal of Conflict Resolution 45(1):126-144. Levy, Jack S. “Qualitative Methods in International Relations.” In Michael Brecher and Frank P.

Harvey, eds., Millennial Reflections on International Studies. Ann Arbor: University of Michigan Press, 2002, pp. 432-54.

Levy, Jack. S. 1988. “Domestic Politics and War.” Journal of Interdisciplinary History

18(4):653-673. Maoz, Zeev and Nasrin Abdolali 1989. “Regime Types and International Conflict, 1816-1976.”

Journal of Conflict Resolution 33:3-35. Maoz, Zeev and Bruce M. Russett. 1993. “Normative and Structural Causes of the Democratic

Peace.” American Political Science Review 87:624-638. Marshall, M. G., and K. Jaggers. 2002. Polity IV Project: Dataset users manual. College Park:

University of Maryland. Miller, Steven V., and Douglas M. Gibler. 2011. “Democracies, Territory and Negotiated

Compromises.” Conflict Management and Peace Science 28:261-279. Mitchell, Sara Mclauglin and Brandon Prins. 1999. “Beyond Territorial Contiguity: Issues at

Stake in Democratic Militarized Disputes.” International Studies Quarterly 43:169-183. Morgan, T. Clifton., and Sally. H. Campbell. 1991. “Domestic Structure, Decisional Constraints,

and War: So Why Kant Democracies Fight?” Journal of Conflict Resolution:187-211. Mousseau, Michael. 2009. “The Social Market Roots of Democratic Peace.” International

Security 33(4):52-86. Murphy, Alexander. 1990. “Historical Justifications for Territorial Claims.” Annals of the

Association of American Geographers 80:531-648.

35

Palmer, David Scott. 1997. “Peru-Ecuador Border Conflict: Missed Opportunities, Misplaced Nationalism, and Multilateral Peacekeeping.” Journal of Interamerican Studies and World Affairs 39(3):109-148.

Park, Johann. 2013. “Forward to the Future: The Democratic Peace after the Cold War.” Conflict

Management and Peace Science, forthcoming. Park, Johann, and Michael Colaresi. Forthcoming. “Safe Across the Border: The Continued

Significance of the Democratic Peace When Controlling for Stable Borders.” Unpublished manuscript.

Rasler, Karen, and William R. Thompson. 2005. Puzzles of the Democratic Peace: Theory,

Geopolitics and the Transformation of World Politics. London: Palgrave Macmillan. Rasler, Karen, and William R. Thompson. 2001. “Rivalries and the Democratic Peace in the

Major Power Subsystem.” Journal of Peace Research 38(6):659-683. Ray, James Lee. 2000. “Democracy: On the Level(s): Does Democracy Correlate with Peace.” In

John A. Vasquez, ed. What Do We Know About War? Lanham, MD: Rowman & Littlefield, pp. 299-316.

Reed, William. 2000. “A Unified Statistical Model of Conflict Onset and Escalation.” American

Journal of Political Science 44(1):84-93. Russett, Bruce M. 1993. Grasping the Democratic Peace: Principles for a Post-Cold War World.

Princeton, NJ: Princeton University Press. Russett, Bruce M. and John R. Oneal. 2001 Triangulating Peace: Democracy, Interdependence,

and International Organizations. New York: Norton. Schultz, Kenneth A. 1999. “Do Democratic Institutions Constrain or inform? Contrasting Two

Institutional Perspectives on Democracy and War.” International Organization 53(2):233-266.

Senese, Paul. D. 1997. “Between Dispute and War: The Effect of Joint Democracy on Interstate

Conflict Escalation.” The Journal of Politics 59(1):1-27. Senese, Paul D. and John A. Vasquez. 2008. The Steps to War: An Empirical Study: Princeton

University Press. Senese, Paul D., and John A. Vasquez. 2005. “Assessing the steps to war.” British Journal of

Political Science 35(4):607-633. Senese, Paul. D., and J. A. Vasquez. 2003. “A Unified Explanation of Territorial Conflict: Testing

the Impact of Sampling Bias, 1919-1992.” International Studies Quarterly 47(2):275-298.

36

Simmons, Beth. 1999. “See You in “Court”? The Appeal to Quasi-Judicial Legal Processes in the Settlement of Territorial Disputes.” In Paul F. Diehl, ed., A Road Map to War: Territorial Dimensions of International Conflict. Nashville and London: Vanderbilt University Press.

Singer, J. David, Stuart Bremer, and John Stuckey. 1972. “Capability Distribution, Uncertainty,

and Major Power War.” In Bruce M. Russett, ed., Peace, War and Numbers. Beverly Hills: Sage Publications.

Small, Melvin, and J. David Singer. 1976 “The War Proneness of Democratic Regimes.”

Jerusalem Journal of International Relations 1(1):50-69. Souva, Mark A., and Brandon Prins. 2006. “The Liberal Peace Revisited: Democracy,

Dependence, and Development in Militarized Interstate Dispute Initiation, 1950-1999.” International Interactions 32 (2):183-200.

Spiro, David E. 1994. “The Insignificance of the Liberal Peace.” International Security 19(2):50-

86. St. John, Ronald Bruce. 1996. “Conflict in the Cordillera del Cóndor: The Ecuador-Peru

Dispute.” IBRU Boundary and Security Bulletin 4(1):78-85. Tomz, Michael, Jason Wittenberg, and Gary King. 2003. “CLARIFY: Software for Interpreting

and Presenting Statistical Results.” Journal of Statistical Software 8(1). Vasquez, John A. 2009. The War Puzzle Revisited. Cambridge: Cambridge University Press. Vasquez, John A. 2004. “The probability of war, 1816-1992.” International Studies Quarterly

48:1-27. Vasquez, John A. 2001. “Mapping the Probability of War and Analyzing the Possibility of Peace:

The Role of Territorial Disputes.” Conflict Management and Peace Science 18(2):145. Vasquez, John A. 1993. The War Puzzle. Cambridge: Cambridge University Press. Vasquez, John A. 1995. “Why Do Neighbors Fight? Proximity, Interaction, or Territoriality.” Journal of Peace Research 32(3):277-293.

37

Table 1. Descriptive Statistics, (1919-1995)

Panel A. Independent and Dependent Variables Variable Mean Std. Dev. Min. Max. MID onset .003 .0580571 0 1 DEMOCRACY .074 .262292 0 1 TERRITORY .009 .0939155 0 1 Capability ratio (logged) 2.39 1.867581 0 11.866 Contiguity .032 .1757473 0 1 Distance (logged) 8.239 .7985807 1.609 9.421 Major power .085 .2791646 0 1 Alliance .071 .256625 0 1 Previous MIDs .082 .7129804 0 30 Peace Years 21.814 24.74007 0 347

Panel B. Cross Tabulation of Democracy and Territory Democratic dyad years Nondemocratic dyad years Sum Territorial claim years

466

(10.55%) (1.26%)

Canada/US (1973-1990)

Japan/South Korea (1960, 1988-1995)

3952

(89.45%) (0.86%)

US/Spain (1923-1931, 1938-1970)

Portugal/Indonesia (1975-95)

4418

(100%) (0.89%)

No territorial claim years

36430

(7.40%) (98.74%)

Colombia/Venezuela (1968-1995)

Gambia/New Zealand (1965-1993)

455595

(92.60%) (99.14%)

US/Portugal (1926-1975)

Malaysia/Singapore (1965-1979)

492025

(100%) (99.11%)

Sum 36896 (7.43%) (100%)

459547 (92.57%) (100%)

496442 (100%)

Note: The number in each cell represents dyad years falling into that cell. In each cell, the percentage in the left parentheses refers to its proportion against the row total while the percentage in the right parentheses refers to its proportion against the column total.

38

Table 2. Probit Models of MID onset, All Dyads (1919-1995)

Model 1 Model 2 Model 3 DEMOCRACY -.469****(.087) -.386****(.081) -.387****(.081) TERRITORY .595****(.061) .625****(.060) .632****(.632) DEMOCRACY × TERRITORY

-.410**(.204) -.266(.254)

Capability ratio -.055****(.011) -.054**** (.011)

-.055**** (.011)

Contiguity .811****(.056) .807****(.056) .807****(.056) Distance -.180****(.020) -.182****(.020) -.183****(.020) Major power .819****(.047) .818****(.047) .822****(.048) Alliance -.093*(.051) -.094*(.051) -.094*(.051) Previous MIDs .068****(.010) .068****(.010) .067****(.010) Peace years -.022****(.003) -.022****(.003) -.022***(.003) Peace years2 .000***(.000) .000****(.000) .000***(.000) Peace years3 -.000***(.000) .000***(.000) .000***(.000) First year democracy -.212(.283) Constant -1.372****(.158) -1.367****(.158) -1.362****(.159) N 496443 496443 496443 log pseudo L -7154.429 -7148.222 -7146.999 Pseudo R2 .363 .363 .364 BIC 14466.240 14466.943 14477.610

Notes: *p<0.1, **p<0.05, ***p<0.01, and ****p<0.001 (one tailed). Robust standard errors, adjusted for clustering on dyad, are in parentheses.

39

Figure 1. Contingent Effects of DEMOCRACY and TERRITORY, All Dyads 1919-1995

1.1. Contingent Effect of DEMOCRACY

Coeff. of Democracy | No Terr. Claim

Coeff. of Democracy | Terr. Claim

Difference in Coefficient

-1.2 -1 -.8 -.6 -.4 -.2 0 .2

Coefficient of Democracy

Mean Coefficient. 95% Confidence Interval

a. Change in Coefficient

Nondem. DyadDem. Dyad

Nondem. Dyad

Dem. Dyad

0.0

02.0

04.0

06P

roba

bilit

y of

MID

No Territorial Claim Territorial Claim

Mean Probability. 95% Confidence Interval

b. Change in Probability

1.2. Contingent Effect of TERRITORY

Coeff. of Territory | Nondem. Dyad

Coeff. of Territory | Dem. Dyad

Difference in Coefficient

-1 -.5 0 .5 1 1.5

Coefficient of Territory

Mean Coefficient 95% Confidence Interval

a. Change in Coefficient

No terr. Claim

Terr. Claim

No Terr. ClaimTerr. Claim

0.0

02.0

04.0

06P

roba

bilit

y of

MID

Nondemocratic Dyad Democratic Dyad

Mean Probability 95% Confidence Interval

b. Change in Probability

Notes: (a) The dot in the first row marks the estimated coefficient for DEMOCRACY (TERRITORY) when TERRITORY (DEMOCRACY) is set at 0. The dot in the second row is for the estimated coefficient of democracy (TERRITORY) when TERRITORY (DEMOCRACY) is set at 1. The third row denotes the difference in coefficient for DEMOCRACY (TERRITORY) across the value of TERRITORY (DEMOCRACY). The horizontal bars represent the confidence intervals for the estimated coefficients. (b) Each dot denotes the estimated probability point of MID onset for a given combination of DEMOCRACY and TERRITORY. Each bar represents the confidence interval for a given point estimate.

Table 3. Probit Models of MID onset, Relevant Dyads (1919-1995)

Model 1 Model 2 Model 3 DEMOCRACY -.453**** (.073) -.429**** (.080) -.429**** (.080) TERRITORY .531**** (.054) .538**** (.054) .539**** (.056) DEMOCRACY × TERRITORY

-.112 (.169) -.090 (.191)

Capability ratio -.075**** (.012) -.074**** (.012) -.074**** (.012) Contiguity .503**** (.059) .503**** (.059) .504**** (.059) Distance -.044* (.024) -.045* (.024) -.045* (.025) Major power .305**** (.058) .306**** (.050) .308**** (.059) Alliance -.084* (.050) -.084* (.050) -.084* (.050) Previous MIDs .060**** (.008) .060**** (.008) .060**** (.008) Peace years -.029**** (.004) -.029*** (.004) -.029*** (.004) Peace years2 .000**** (.000) .000**** (.000) .000**** (.000) Peace years3 -.000*** (.000) -.000*** (.000) -.000*** (.000) First year democracy -.035 (.189) Constant -1.652**** (.174) -1.650**** (.173) -1.648**** (.175) N 57584 57584 57584 log pseudo L -5280.931 -5280.538 -5280.506 Pseudo R2 .222 .222 .222 BIC 10693.394 10703.568 10714.465

Notes: *p<0.1, **p<0.05, ***p<0.01, and ****p<0.001 (one tailed). Robust standard errors, adjusted for clustering on dyad, are in parentheses.

1

Figure 2. Contingent Effects of DEMOCRACY and TERRITORY, Relevant Dyads (1919-1995)

2.1. Interactive Coefficients for DEMOCRACY

Coeff. of Democracy | No Terr. Claim

Coeff. of Democracy | Terr. Claim

Difference in Coefficient

-1 -.8 -.6 -.4 -.2 0 .2 .4

Coefficient of Democracy

Mean Coefficient. 95% Confidence Interval

2.2. Interactive Coefficients for TERRITORY

Coeff. of Territory | Nondem. Dyad

Coeff. of Territory | Dem. Dyad

Difference in Coefficient

-.6 -.4 -.2 0 .2 .4 .6 .8 1

Coefficient of Territory

Mean Coefficient 95% Confidence Interval

2

Table 4. Probit Models of MID onset for ICOW Dyads

Model 1 Model 2 Model 3 DEMOCRACY -.201** (.092) -.225** (.088) -.790*** (.231) SALIENCE .027* (.015) .028** (.014) .019 (.014) DEMOCRACY × SALIENCE

.075*** (.029)

Capability ratio -.044* (.023) -.055*** (.019) -.058** (.019) Contiguity .034 (.134) .034*** (.008) Distance -.007 (.055) Major power -.050 (.091) Alliance -.035 (.008) Previous MIDs .035**** (.008) .034**** (.008) Peace years -.048**** (.007) -.049**** (.007) -.049**** (.007) Peace years2 .001**** (.000) .001**** (.000) .001**** (.000) Peace years3 -.000*** (.000) -.000**** (.000) .000**** (.000) Constant -1.222*** (.409) -1.246**** (.167) -1.178**** (.165) N 7210 7210 7210 log pseudo L -1602.613 -1603.661 -1600.884 Pseudo R2 .120 .120 0.121 BIC 3311.825 3278.387 3281.717

Notes: *p<0.1, **p<0.05, ***p<0.01, and ****p<0.001 (one tailed). Robust standard errors, adjusted for clustering on dyad, are in parentheses.

3

Figure 3. Contingent Effects of DEMOCRACY and SALIENCE, ICOW Dyads 3.1. Changes in Coefficient (DEMOCRACY) 3.2. Changes in Coefficient (SALIENCE)

-1.5

-1-.

50

.5

Coe

ff. o

f Dem

ocra

cy

0 1 2 3 4 5 6 7 8 9 10 11 12

Issue Salience

Mean Coefficient 95% Confidence Interval

Coeff. of Salience | Nondem. Dyad

Coeff. of Salience | Dem. Dyad

Difference in Coefficient

-.05 0 .05 .1 .15 .2

Coefficient of Salience

Mean Coefficient 95% Confidence Interval

3.3. Predicted Probabilities of MID Contingent upon DEMOCRACY and SALIENCE

0.0

2.0

4.0

6.0

8.1

.12

Pro

b. o

f MID

0 1 2 3 4 5 6 7 8 9 10 11 12

Issue Salience

Nondemocracy Democracy

Notes: (1) The dots and vertical bars represent the mean coefficients for DEMOCRACY and their 95% confidence intervals across the levels of SALIENCE. (2) The dot and horizontal bar in the first (second) row marks the mean coefficient for issue salience and its 95% confidence interval for non-democratic (democratic dyads). The third row is for the difference in coefficient for SALIENCE across dyadic regime types. (3) The solid line traces the mean probabilities of MID onset for democratic dyads with their 95% confidence intervals across the levels of SALIENCE. The dashed line is for nondemocratic dyads.