Signing Up for Peace: International Boundary Agreements, Democracy, and Militarized Interstate Conflict1

Abstract

Can states usher in more peaceful relations with their neighbors by signing agreements that delineate their territorial boundaries? Theory suggests such a possibility, but the empirical evidence to date remains limited by research design and variable measurement decisions. After assembling a new data set on international boundary agreements, the current study conducts the first thorough test of this question during the period 1816-2001. The findings indicate that once neighboring states settle their borders, they are less likely to go to war or experience militarized interstate disputes with one another. These pacific effects persist across numerous time periods even after controlling for joint democracy, a characteristic that both theory and this analysis show to be positively related to settled borders. Through these findings, the study suggests that signing international boundary agreements can bring neighbors a more peaceful relationship with one another, regardless of the characteristics of their respective governmental regimes.

Democratization and International Border Agreements

“…Finally, Vasquez (2009) behavior designed to obtain and hold territory. Owsiak (2012) confirms this finding for a longer period using a more direct measure of border settlement. Vasquez's (2009) latter proposition receives strong empirical support.…”

“…The foundations of this argument lie within a rich research program investigating the particularly dangerous nature of territorial disputes (e.g., Holsti 1991; Huth 1996; see Tir and Vasquez 2010 for a review). Thus, when states have not agreed upon (i.e., settled) their borders with neighbors, they are more likely to experience conflict over any issue (Owsiak 2012) and to develop interstate rivalries with one another (Owsiak and Rider 2013). Yet it also recognizes that not all territorial disputes induce violent conflict.…”

“…He predicts both that interstate borders will frequently cause tension as a result of this territoriality and that settling these borders will transform relations between neighboring states. More specifically, Owsiak (2012) argues that we need not rely on proxy measures of settled borders when direct behavioral measures of the desired concept exist (see also Rasler and Thompson 2011). Gibler (2012), for example, argues that unsettled borders constitute a salient external threat that disappears after border settlement.…”

“…Vasquez's (2009) latter proposition receives strong empirical support. In the end, Owsiak (2012) finds that once states sign such agreements, they are less likely to fight militarily over any issue. Consistent with this expectation, he finds that settled borders reduce the likelihood of conflict among neighbors.…”

“…These categories follow the suggestion of the Polity IV project(Marshall and Jaggers 2009).11 For precise coding rules and examples, seeOwsiak (2012).12 Gibler(2012)uses more indirect (proxy) measures, some of which prevent one from knowing when to expect democratization. FollowingOwsiak (2012) andRasler and Thompson (2011), I therefore employ a direct measure, which produces clear expectations about democratization. See the online appendix for more information.13 I start with 169 states.…”