Beyond Territorial Contiguity: Issues at Stake in Democratic Militarized Interstate Disputes

Scholars of international politics have been slow to address the fundamental issues that ground interstate conflict. Territory has frequently been cited as a primary source of contention among states, but it remains only one issue and not even the one most prevalent in the post–World War II time period. We take the first step toward understanding the broader theoretical link between regime type, issues, and militarized conflict by collecting new data on the issues in dispute between democracies from 1946 to 1992. We findthat (1) a large proportion of the militarized disputes between democracies in the post-WWII period involve fisheries, maritime boundaries, and resources of the sea, (2) well-established democracies are able to remove territory as a contentious issue among them, (3) disputes between democracies have become less severe and shorter in duration over time, and (4) a majority of the post-WWII militarized disputes between democracies are not resolved. We conclude with a discussion of the implications of these empirical findings for the democraticpeace literature.     

The Chicken or the Egg?: A Coevolutionary Approach to Disputed Issues and Militarized Conflict

Is state behavior influenced by the context in which it occurs, or does context arise because of the way in which states behave? I investigate these questions in the context of international disputes over issues and states’ militarized behavior. The prevalent assumption in interstate conflict research is that disputed issues are exogenous to militarization patterns. I question the validity of this assumption, arguing there are reasons to suspect certain states self-select into disputes. I use a coevolution modeling strategy to allow the existence of disputes and states’ behavior to mutually affect one another. I find disputes are not exogenous to states’ militarized behavior. States that resort to militarized behavior are more likely to dispute an issue than peaceful states. I also find evidence of behavioral contagion among states engaged in disputes: Militarized behavior begets militarized behavior.     

“Opportunity” and “willingness’ as ordering concepts in the study of war

The peace through trade hypothesis receives extensive support from a large empirical literature. However, extant research does not isolate whether this relationship holds for states that have fought in the past, or whether its influence following armed disputes is dependent upon the ways in which states settle their conflicts. Additionally, although recent research finds that imposed settlements are more pacifying than other forms of political settlement, these studies tend not to isolate factors associated with variation in the stability of imposed settlements. In this article, we examine how settlements condition the influence of trade on conflict recurrence, both to overcome a limitation in extant studies of trade and conflict, which tend to ignore the way states settle prior disputes, and to further an understanding of how post-conflict state interaction varies by (and within) settlement type. Looking at dyadic trade and recurrent conflict from 1885 to 2000, we find that imposed settlements foster a pacifying effect of trade, while negotiated settlements and failures to reach settlement lead to relationships in which trade has crosscutting effects on the stability of peace, resulting in an overall null effect of trade on conflict recurrence.     

Cantankerous Cooperation: Democracies,Authoritarian Regimes,and the Prisoner's Dilemma

One of the most important debates in the field of international relations is over the effect of regime type on militarized conflict. This debate, however, has rarely extended to how regime type influences other aspects of foreign policy. Using a computer simulated intergroup prisoner's dilemma, we investigate whether democratic decisionmaking groups are more cooperative than authoritarian decisionmaking groups. We argue that differences between cooperation tendencies of groups can be explained by the structure of the decision process. Repeated simulations show that democracies tend to be more consistent in their decisions in comparison to authoritarian groups. Implications for international relations theory and policy are discussed.     

Kantian Dynamics Revisited: Time-Varying Analyses of Dyadic IGO-Conflict Relationships

ABSTRACT

The literature on international organizations (IGOs) and interstate conflict in world politics produces a series of contradictory theoretical arguments and empirical findings about how IGOs help to prevent conflict and promote peace between member states. Empirical studies find a range of inconsistent results, ranging from pacifying effects of shared IGO memberships on dyadic militarized disputes to conflict-inducing effects of shared IGO memberships to null relationships. Theoretically, we consider how IGOs promote the rule of peace preservation through the mechanisms of coercion, self-interest, and legitimacy, and we describe how these mechanisms help explain the time-varying relationships between shared IGOs memberships and militarized conflict since WWII. Analyses of time-varying parameter models of dyad-year data from 1948 to 2000 suggest that shared IGO memberships reduce the likelihood of militarized conflict in some historical periods (Cold War) but increase the chances for dyadic conflict in other periods (post-Cold War). The design of IGOs is relevant as well, with security-based, highly institutionalized IGOs best suited to prevent militarized conflict between member states. The results suggest that evolutionary dynamics in the Kantian peace vary across legs of the Kantian tripod and that we cannot understand the Kantian peace without considering dynamic relationships over time.     

Preferences and the Democratic Peace

A debate exists over whether (and to what degree) the democratic peace is explained by joint democracy or by a lack of motives for conflict between states that happen to be democratic. Gartzke (1998) applies expected utility theory to the democratic peace and shows that an index of states' preference similarity based on United Nations General Assembly roll-call votes ( affinity ) accounts for much of the lack of militarized interstate disputes (MIDs) between democracies. Oneal and Russett (1997b, 1998, 1999) respond by arguing that UN voting is itself a function of regime type—that democracy 'causes' affinity . Oneal and Russett seek to demonstrate their thesis by regressing affinity on democracy and other variables from a standard model of the democratic peace. I replicate results reported by Oneal and Russett and then extend the analysis in several ways. I find that the residuals from Oneal and Russett's regression of affinity remain highly significant as a predictor of the absence of MIDs. Further, significance for democracy is shown to be fragile and subject to variable construction, model specification, and the choice of estimation procedure.     

Assessing the statistical rarity of wars between democracies

The ‘small numbers objection’ to the democratic peace claims that the relative rarity of militarized conflict between democracies is due to their small numbers coupled with the infrequency of violent interstate conflict, not to an alleged pacifying effect of democracy. This study assesses this objection directly by treating the number of militarized disputes between democracies as a random variable. Since the historical record provides only one observation for this variable, full estimation of its distributional characteristics requires repeated simulation of the process by which dyads are ‘selected’ for conflict We employ Monte Cario techniques to carry out this process. The simulation results indicate no support for the small numbers objection. The results remain stable when important control variables are introduced and when the analysis employs a weaker definition of democracy. Finally, the simulation enables a precise identification of the point within the 1816–1992 temporal domain when the democratic peace moved from an apparent statistical artifact to significant phenomenon.     

Social and Political Cultural Effects on the Outcomes of Mediation in Militarized Interstate Disputes

The article investigates the relationship between cultural similarities and differences on the part of the representatives of contending states and mediators, and outcomes of mediation efforts in militarized disputes. A distinction is made between social culture, defined primarily in terms of religious identity, and political culture, defined according to the state's political system. Analysis of 752 mediation attempts in militarized disputes occurring between 1945 and 1995 yields support for the hypothesis that mediation is more likely to succeed when the parties are from similar social cultures. The results, however, suggest that the relationship is more complex than that suggested by a simple categorization of states based on Huntington's "clash of civilizations" thesis. We also find that mediation is more likely to succeed when the parties share democratic political cultures, a finding that is consistent with the cultural/normative explanation for the democratic peace.     

The Liberal Peace Revisited: The Role of Democracy,Dependence, and Development in Militarized Interstate Dispute Initiation, 1950–1999

We test a model of the liberal peace by examining the initiation of militarized interstate disputes at the monadic level of analysis from 1950–1999. Liberal peace theory contends that both economic dependence and democratic political systems reduce conflict propensities. Extant empirical analyses of the monadic liberal peace, however, are under-specified. First, the concept of economic dependence not only includes trade, but also foreign investment. Second, existing models do not control for the influence of economic development. Previous research on the monadic liberal peace has also failed to distinguish between the initiation of conflict and participation in conflict. We find evidence for a liberal peace: trade dependence, foreign investment, and democracy reduce a state’s propensity to initiate militarized disputes.     

The Joint Democracy–Dyadic Conflict Nexus: A Simultaneous Equations Model

Many statistical studies in international relations investigate the claim that democracies do not fight one another. Virtually all of these studies employ a single-equation design, where the dependent variable measures the presence or absence of a dyadic militarized interstate dispute (MID). A separate group of studies argues that conflict affects democracy and that its effect could be positive or negative. By and large, these two bodies of literature have not incorporated one another's insights. We argue that democracy and dyadic conflict affect each other significantly and that statistical models that ignore the reciprocal nature of these effects may make incorrect inferences. To test this argument, we develop a simultaneous equations model of democracy and dyadic conflict. Our sample includes all the politically relevant dyads from 1950 to 1992. We find that dyadic military disputes reduce joint democracy and joint democracy reduces the probability of MIDs. Compared with the single-equation estimates in the literature, the absolute effect of joint democracy in our paper is smaller while in relative terms, the effect is similar in size. The effect of joint democracy on MID involvement is considerably smaller for noncontiguous countries than for contiguous ones. The effects of a number of control variables in the MID equation are also found to differ from those reported previously in single- equation–based studies.     

Militarized Interstate Disputes and United States Uses of Force

Research on questions such as whether national leaders use force in the international arena to divert attention from problems at home depends on a valid and reliable list of the incidents in which various states have used military force. In the case of the United States, several data sets have been used for this purpose. This research note compares two widely used data sets, the militarized interstate disputes (MID) data, which cover disputes involving all states between 1816 and 1992, and the data originally compiled by Stephen Kaplan and Barry Blechman, which cover only the United States since World War II. This comparison indicates that, in spite of its usefulness for other conflict research, the MID data are not appropriate for analyses of U.S. decisions to use force, including tests of the diversionary hypothesis. The MID data set excludes several categories of incidents relevant to major theoretical arguments about the use of force and includes many irrelevant incidents. These problems are likely to apply to similar analyses of other states as well. The Blechman and Kaplan data set also excludes some relevant events, but its omissions are less consequential. We offer a revised list of United States uses of force between 1870 and 1995.     

Causes of Peace: Democracy, Interdependence, and International Organizations, 1885–1992

Previous studies provide strong evidence for the Kantian theory of peace, but a satisfactory evaluation requires establishing the causal influence of the variables. Here we focus on the reciprocal relations between economic interdependence and interstate conflict, 1885–1992. Using distributed-lags analyses, we find that economically important trade does have a substantively important effect in reducing dyadic militarized disputes, even with extensive controls for the influence of past conflict. The benefit of interdependence is particularly great in the case of conflict involving military fatalities. Militarized disputes also cause a reduction in trade, as liberal theory predicts. Democracy and joint membership in intergovernmental organizations, too, have im-portant pacific benefits; but we find only limited support for the role of costly signals in establishing the liberal peace. We find no evidence that democratization increases the incidence of interstate disputes; and contrary to realists' expectations, allies are not less conflict prone than states that are not allied. Democracies and states that share membership in many international organizations have higher levels of trade, but allies do not when these influences are held constant.     

War, Peace, and the Invisible Hand: Positive Political Externalities of Economic Globalization

Studies of signaling in international relations reveal how punishing bluffing ex post through domestic audience costs or opposition groups facilitates credible ex ante communication among states and reduces the impetus toward war. Global integration of economic markets may also reduce uncertainty by making talk costly ex ante. Autonomous global capital can respond dramatically to political crises. To the degree that globalization forces leaders to choose between pursuing competitive political goals and maintaining economic stability, it reveals the intensity of leaders' preferences, reducing the need for military contests as a method of identifying mutually acceptable bargains. Asymmetric integration can dampen the pacific effects of globalization, but asymmetry does not in itself exacerbate dispute behavior. We present the theory and offer preliminary corroborative tests of implications of the argument on postwar militarized disputes.     

Dyadic effects of democratization on international disputes

I explore the dyadic, as opposed to monadic, effect of democratizationon war. Using a simple repeated game of interstate interaction,I show that, as a state shifts towards democracy, its citizensaquire more opportunities and become more willing to removethose leaders that they expect will reduce their welfare. Rationalleaders anticipate this consequence, and their incentives tomaintain cooperative relationships with other democracies increaseas their states become democratic. The hypothesis drawn fromthe model predicts that democratization will have a pacifyingeffect in a dyadic relationship between democracies. Empiricaltesting is designed to isolate the dyadic effect from the monadicand to distinguish among competing hypotheses. The predictionsare tested with widely used data on political institutions andmilitarized interstate disputes. The result shows that democratizationindeed reduces the likelihood of waging war. However, this pacifyingeffect is largely attributed to the dyadic effect with a democraticopponent; the risk of war remains unchanged when facing a non-democraticopponent.     

Democracy,Regional Security Institutions,and Rivalry Mitigation: Evidence From Europe,South America,and Asia

The fact that democracies maintain peaceful relations with each other is regarded as one of the few law-like correlations in international relations, but the causes of this empirical phenomenon remain contested. This paper tries to fill this theoretical gap by attributing the remarkable stability between democracies to inter-democratic institutions. At the same time, it contributes to the debate on the need to differentiate among international organizations in order to assess their peace-building effects. We identify transnational and trans-governmental linkages as crucial features that distinguish inter-democratic from traditional institutions with non-democratic or mixed membership. In order to explain these institutions’ peace-building effect, we analyze the impact of international institutions on rivalry mitigation with a view to five pairs of states: France-Germany, Greece-Turkey, Argentina-Brazil, Indonesia-Malaysia, and Japan-South Korea. Those dyads all look back at a history of rivalry, conflict, and mutual threat perceptions, and they are located in highly institutionalized regional settings but vary with regard to their political regime type. The controlled comparison of cases demonstrates that the embeddedness of international institutions in transnational and trans-governmental linkages corresponds to each member's regime type and that these institutional differences are responsible for the varying extent of rivalry mitigation.     

The Economic Leverage of International Organizations in Interstate Disputes

Addressing a long-standing debate in international relations scholarship, this study shows that international governmental organizations (IGOs) with high economic leverage over their member states, such as some development banks, substantially lower the risk that political disputes experience the use of military force. Empirical tests covering cases of disputatious claims and international crises since 1946 make use of a new classification of IGOs that have economic leverage and use it toward increasing states’ cost of using force in disputes. When pairs of states are subject to the economic leverage of IGOs, they are substantially less likely to use force. For the understanding and practice of interstate dispute resolution and international conflict more generally, the study suggests a specific linkage between institutionalized economic interdependence and conflict escalation.     

Finding peace in a world of hegemony and terrorism

Although acknowledging the importance of power, Immanuel Kantsuggested that republican constitutions, economic interdependence,and international law and organizations can form the basis fora dramatically more peaceful world. Statistical analyses ofthe behavior of pairs of states, 1885–1992, confirm thisliberal vision. Using methods common to medical epidemiology,we find that the Kantian elements substantially reduce the likelihoodthat states will become involved in a fatal militarized dispute.Indeed, two democracies linked by extensive trade and a densenetwork of international organizations are 95% less likely tofight than states that do not share these characteristics. Ouranalyses have important implications for the United States andChina, two countries destined to shape the twenty-first century.Engaging China in trade and integrating it into the major internationalorganizations over the last three decades has, with some liberalizationof its government, substantially reduced the risk of militaryconflict.     

Turning down the heat: Influences on conflict management in enduring rivalries

Enduring rivalries represent the most difficult challenges for policy makers seeking to promote international peace and security. Once in place, enduring rivalries account for a disproportionate number of crises, militarized disputes, as well as wars, and include conflicts that are more likely to escalate than those falling in other conflict contexts. Unfortunately, we know very little about conflict management in enduring rivalries from either a theoretical or policy perspective. This study seeks to account for why some rivalries are successfully managed while others persist at high and unabated levels of conflict In addressing these concerns, we explore 35 enduring rivalries over the period 1945–1992. We find that although enduring rivalries are quite resistant to influences that produce changes in their dynamics, both endogenous and contextual influences can exercise a significant impact upon the prospects for conflict management between enduring rivals.     

A Unified Explanation of Territorial Conflict: Testing the Impact of Sampling Bias, 1919–1992

This article develops a new unified territorial explanation of conflict that accounts for the possibility of certain factors affecting the rise of a militarized dispute, as well as the probability that a dispute will escalate to war. In the past, research linking territorial disputes to a relatively high probability of war outbreak has been criticized for underestimating the potential problem of sampling bias in the militarized interstate dispute (MID) data. This study utilizes newly available data on territorial claims going back to 1919 to determine, using a two-stage estimation procedure, whether the presence of territorial claims in the dispute onset phase affects the relationship between territorial militarized disputes and war in the second stage. It is found that territorial claims increase the probability of a militarized dispute occurring and that territorial MIDs increase the probability of war, even while controlling for the effect of territorial claims on dispute onset. The effect of territory across the two stages is consistent with the new territorial explanation of conflict and war and shows no sampling bias with regard to territory in the MID data.