Brett V. Benson

Unpacking Alliances: Deterrent and Compellent Alliances and Their Relationship with Conflict, 1816–2000

Do alliances deter aggression? I develop a typology of deterrent and compellent military alliances to better define the possible conditions for intervention and use new data from 1816 to 2000 to analyze the relationship between alliances and conflict. First, unconditional compellent alliances, a category that represents a minority of alliances, are associated with a 249% increase in the likelihood of conflict when the prospective initiator is an alliance member. Such alliances are especially associated with violent conflict. Second, conditional compellent alliances exhibit no discernible relationship with conflict. Third, deterrent alliances contingent upon the adversary’s attack are associated with an 18% decrease in the likelihood a third party will initiate a conflict with an alliance member. Minor powers holding such alliances with major powers are unlikely to be attacked violently. Fourth, other categories of deterrent alliances do not deter violent conflict. In fact, deterrent alliances that permit ...

Inducing Deterrence through Moral Hazard in Alliance Contracts

Do military alliances foster aggressive behavior in allies to the point of undermining the security goal of the alliance? Like others, we find that alliance commitments may cause moral hazard because allies do not fully internalize the costs of actions that can lead to war. But unlike others, we show that the effect of moral hazard can improve security. Moral hazard can be the driving force behind generating deterrence and avoiding costly conflict. Aggressors may refrain from initiating crises if their target enjoys additional resources from its ally and so is more willing to fight back. So rather than incurring costs, moral hazard may be the very key to deterring potential aggressors and minimizing the risk of conflict. This behavior allows alliance partners to capture a “deterrence surplus,” which are the gains from avoiding conflict.

Ally provocateur Why allies do not always behave

The primary purpose of many alliances is to deter attacks on members of the alliance by potentially antagonistic states. Yet some alliances can increase the probability of conflict that may be initiated by alliance members. Cognizant of that possibility, states that wish to sustain peace may nevertheless intentionally form alliance commitments with revisionist leaders of other states. Faced with the partially conflicting goals of deterring antagonistic states while at the same time restraining allies, leaders often include in alliance treaties conditions that oblige allies to provide military assistance only if a member of the alliance is attacked by a state outside the alliance. However, other treaties may contain unconditional obligations to come to the defense of members of the alliance. Such alliances tend to arise from situations where some members of the alliance feel that their alliance partners need to have the flexibility even to engage in provocative behavior in order to deter the target of the alliance. Our analysis of alliance formation processes in the context of priorities that compete with each other provides a basis for two hypotheses. The first is that revisionist states with unconditional commitments from members of their alliance to come to their defense are more likely to initiate militarized conflict than states without such unconditional commitments. The second hypothesis is that revisionist states in alliances whose treaties stipulate that commitments to defend are conditional will be less likely to initiate militarized conflict than such states with allies who are committed to come to their defense without conditions. Statistical analyses of data generated with a view toward evaluations of both hypotheses (some of which provide new, more detailed categorizations of alliance treaties) suggest that they are valid.

Economic Interdependence and Peace: A Game-Theoretic Analysis

Most of the contemporary policy debate regarding economic interdependence and peace has focused on devising responses either in favor of or in opposition to the prevailing notion that trade is positively and unconditionally correlated with peace. The China and Taiwan case—noteworthy for the simultaneous presence of an ever-increasing economic interdependence and an adversarial political relationship—provides an interesting counterexample to the leading positions in the literature. What is missing in the literature is a model that studies states’ decisions to trade and initiate conflict as a function not only of their own utility but also of their perceptions about how their opponent will respond. States’ decisions to trade depend on the likelihood that their prospective trade partner will initiate a conflict, and decisions to initiate a conflict depend on perceptions of the likelihood that the target will concede. In this article, the authors develop a model that expands the domain of the trade-peace analysis by endogenizing and analyzing states’ decisions to trade and initiate conflicts.

Assessing the Variation of Formal Military Alliances

Many critical questions involving the causes and consequences of formal military alliances are related to differences between various alliances in terms of the scope of the formal obligations, the depth of the commitment between signatories, and the potential military capacity of the alliance. Studying the causes and consequences of such variation is difficult because while we possess many indicators of various features of an alliance agreement that are thought to be related to the broader theoretical concepts of interest, it is unclear how to use the multitude of observable measures to characterize these broader underlying concepts. We show how a Bayesian measurement model can be used to provide parsimonious estimates of the scope, depth, and potential military capacity of formal military alliances signed between 1816 and 2000. We use the resulting estimates to explore some core intuitions that were previously difficult to verify regarding the formation of the formal alliance agreement, and we check the validity of the measures against known cases in alliances as well as by exploring common expectations regarding historical alliances.

Changing capabilities, uncertainty, and the risk of war in crisis bargaining

Understanding how changes to war-fighting technology influence the probability of war is central to security studies. Yet the effects of changes in the distribution of power are not obvious. All else equal, increasing a country’s power makes it more aggressive when making demands or more resistant to accepting offers, but all else is not equal. Changes in power influence the behavior of both countries and can generate countervailing incentives. In this note we characterize the conditions relating changes in war payoffs to changes in the probability of bargaining failure and war. For a variety of cases the strategic effects can be entirely offsetting and no change in the probability of war results from changes in the balance of power, a result sometimes called neutrality. When this neutralization does not occur, interesting and sometimes surprising effects can persist. For example, if countries are risk averse and neutrality fails, then supporting the weaker country can reduce the probability of war rather than make war more likely, even though the weaker side will now make higher demands and reject more proposals in favor of war.

Measured Strength: Estimating the Strength of Alliances in the International System, 1816-2000

Alliances play a critical role in the international system and understanding the determinants and consequences of their strength is an important task. Even though many have argued that the strength of an alliance is theoretically determined by both the power of the signatories involved and the formal terms of the agreement, using these insights to measure the strength of alliances is difficult for many reasons. Using a statistical measurement model, we estimate the strength of all alliances signed between 1816-2000 along two theoretically derived dimensions: the strength of the signatories involved, and the strength of the formal terms of the alliance. In addition to estimating the strength of every alliance in these two dimensions, our Bayesian latent variable model also allows us to: characterize the relationship between the two dimensions of alliance strength, identify how observable characteristics relate to each of the recovered dimensions, and, perhaps most importantly given the difficulty of the task, document how precisely we are able to use the measures to estimate alliance strength. By generating estimates of every alliance signed between 1816 and 2000, we not only provide scholars with an empirical characterization of alliance strength in two dimensions of conceptual interest that should prove vital for future studies of international alliances, but the flexibility of our measurement model also offers additional opportunities to refine and extend our measure.