Brett Ashley Leeds

Alliance Treaty Obligations and Provisions, 1815-1944

This article introduces the Alliance Treaty Obligations and Provisions (ATOP) dataset. We begin by describing the rationale for collecting the ATOP data, its scope, and some general coding rules for the project. Then we offer some descriptive statistics for phase one of the dataset, which covers the years 1815-1944, and reveal some interesting trends in alliance politics. Finally, we replicate a study of alliance formation originally conducted by Lai and Reiter (2000) to demonstrate the effect the use of ATOP data may have on past inferences about alliance politics.

Alliance Reliability in Times of War: Explaining State Decisions to Violate Treaties

Understanding the conditions under which state leaders are willing to honor alliance commitments in war will increase knowledge about the escalation and diffusion of conflict and about the propensity of states to fulfill agreements under anarchy. New data analysis provides evidence that alliance commitments are fulfilled about 75 percent of the time. But how can one understand the failure of alliance partners to act as promised in the remaining 25 percent of cases? Formal modelers have deduced that because of the costs associated with alliances, state leaders who form alliances are likely to fulfill them; those alliances that are formed should be fairly reliable. I argue, therefore, that one can best account for violations of alliance agreements either through an understanding of the factors that reduce the costs of violation or through changes that have occurred since the alliance was formed. Using detailed data on alliance commitments between 1816 and 1944, I find evidence commensurate with this argument. Changes in the power of states or in their policymaking processes are powerful predictors of the failure to honor past commitments; and nondemocratic states and major powers, sets of states that I argue suffer lower costs from reneging on agreements, are more likely to violate treaties.

Domestic Political Vulnerability and International Disputes

The proposition that domestic political vulnerability provides an incentive for leaders to engage in international conflict has been widely accepted because of appealing logic and anecdotal support. Although empirical studies of U.S. behavior during the cold war era have demonstrated some support for a relationship between domestic political vulnerability and aggressive international behavior, the generalizability of these tests should not be assumed. In fact, there is little empirical evidence in support of this relationship as a general pattern. This study assesses theories linking domestic political vulnerability to international disputes on a cross-national basis by examining the relationships between economic decline, the electroal cycle, and measures of aggressive international action for 18 advanced industrialized democracies during the period from 1952 to 1988. The authors find no consistent support for a relationship between constraining domestic political conditions and international behavior. Instead, fewer international demands are made on politically vulnerable leaders. Due to strategic interaction in the international system, just when a state leader might be most willing to act aggressively, he or she is likely to have the least opportunity to do so. Variance in the behavior of international rivals may explain the lack of an empirical relationship between domestic political conditions and foreign policy behavior.

Do Alliances Deter Aggression? The Influence of Military Alliances on the Initiation of Militarized Interstate Disputes

Scholars have long debated the effects of military alliances on the likelihood of war, and no clear support has emerged for the argument that alliances improve the prospects for peace through effective deterrence nor that they kindle the flames of war. In this study, I argue that alliance commitments affect the probability that a potential challenger will initiate a militarized interstate dispute because alliances provide information about the likelihood that others will intervene in a potential conflict. Yet, different agreements provide different information. Alliance commitments that would require allies to intervene on behalf of potential target states reduce the probability that a militarized dispute will emerge, but alliance commitments promising offensive support to a potential challenger and alliances that promise nonintervention by outside powers increase the likelihood that a challenger will initiate a crisis. As diplomats have long understood, the specific content of international agreements helps to determine their effects.

Reevaluating Alliance Reliability Specific Threats, Specific Promises

Previously reported empirical evidence suggests that when conflict arises, military alliances are not reliable; state leaders should only expect their alliance partners to join them in war about 25% of the time. Yet, theoretical arguments explaining the choices of leaders to form cooperative agreements are at odds with such empirical evidence. This puzzling gap between theory and evidence motivates a reconsideration of previous measures of alliance reliability. Many alliance treaties include specific language regarding the circumstances under which the alliance comes into effect, often limiting obligations to disputes with specific target states or in specific geographic areas, and many treaties do not go so far as to require states to join in active fighting. Considering the specific obligations included in alliance agreements provides an improved estimate of the propensity of states to honor their commitments. Results show that alliances are reliable 74.5% of the time.

Terminating Alliances: Why Do States Abrogate Agreements?

Are binding international agreements only valuable as matters stand (rebus sic stantibus), or are pacts respected in good faith regardless of changing circumstances (pacta sunt servanda)? In this article, we examine this question with respect to military alliance agreements, and we find that alliances are more likely to be abrogated opportunistically when one or more members experience changes that affect the value of the alliance, for instance a change in international power, a change in domestic political institutions, or the formation of a new outside alliance. We also find, however, that controlling for such changes, factors that affect the costs of breaking commitments (for example, democracy and issue linkage) reduce the probability that leaders will abandon their alliances in violation of their terms. We evaluate our argument empirically on a sample of bilateral alliances formed between 1816 and 1989 using competing risks duration analysis and find support for our hypotheses.

Trading for Security: Military Alliances and Economic Agreements*

The authors appraise a well-known argument connecting economics and security in international relations: military allies are likely to trade more with one another than non-allies. A review of alliance treaties and diplomatic history suggests that, under certain conditions, states may tie together alliance agreements and economic agreements. When states explicitly link alliance agreements with economic cooperation, one would expect to see increased economic exchange coinciding with coordinated security policies. This article evaluates whether the linking of economic and security agreements accounts for a positive relationship between alliances and trade among European states before World War II and produces evidence in support of this argument. Trade among allies who have specified economic cooperation in their alliance agreements is higher than trade among non-allied states and higher than trade among allies who have not promised economic cooperation. In contrast, trade among allies without specific economic provisions in their treaties is statistically no different from trade among non-allies. Thus, the positive empirical relationship between alliances and trade that the authors find in pre-WWII Europe is a result of only a specific subset of all military alliances, namely, those treaties that stipulate economic cooperation between the allies. This study advances our understanding of the alliance–trade relationship by focusing attention on the joint negotiation of cooperation in different issue-areas.

Alliance Institutionalization and Alliance Performance

Military alliances are formed with varying degrees of institutionalization. While some alliances involve little initial investment or joint planning, others involve significant peacetime costs in establishing formal structures and engaging in military coordination. Several scholars have addressed the reasons states are willing to pay these governance costs in establishing cooperation—through controlling the risks of opportunism and coordinating policy more extensively, state leaders may be able to achieve higher benefits from cooperation. What has received less systematic empirical attention, however, is the comparative performance of highly institutionalized alliances. Are alliances that represent “deeper” cooperation more reliable than their less institutionalized counterparts? The newly expanded Alliance Treaty Obligations and Provisions (ATOP) dataset includes detailed information about the institutionalization of alliances formed between 1815 and 1989. Using these data, we evaluate the effects of institutionalization on alliance performance. Surprisingly, we find no evidence that alliances with higher levels of peacetime military coordination or more formal alliances are more reliable when invoked by war. We speculate about directions for future research that might help to explain these results.

Alliance Politics during the Cold War: Aberration, New World Order, or Continuation of History?

Scholars have often wondered whether the nature of alliance politics fundamentally changed during the bipolar nuclear era characterized by the Cold War. The extension of the Alliance Treaty Obligations and Provisions (ATOP) dataset to include the years from 1815 to 2003 allows us the ability to evaluate systematically whether the Cold War period was an aberration, different both from the periods that preceded it and those that followed it, the beginning of a new alliance politics that has continued in the post—Cold War era, or similar in dynamics to eras both before and since. We begin this descriptive project here. While we find some evidence of the distinctness of the Cold War era, what is more notable in the design of alliances is a trend over time away from “reactive alliances” (which are designed to deal with specific crises) and toward “standing alliances” (which are broader and more enduring). In terms of the effects of alliances, we do find evidence that Cold War dynamics are distinct from those of prior eras. In a replication of a well-known study by Russett and Oneal (2001), we reinforce the finding that shared alliance commitments are related to peace during the Cold War, but not in earlier eras. In addition, we demonstrate that the effect of shared alliances on peace depends on the type of alliance commitment.

To concede or to resist? The restraining effect of military alliances

Creating institutions that effectively manage interstate conflict is a priority for policy-makers. In this article we demonstrate that military allies are well positioned to influence the crisis-bargaining behavior of both challengers and targets in ways that often lead to peace. Through a three-player game-theoretic model, we demonstrate that a targets alliances not only have an effect on the demand that the challenger makes, but also on the behavior of the target. When a target values an alliance highly, an allys recommendation for settlement can encourage the target to concede to demands without further escalation. Our statistical analysis provides evidence in support of the theoretical finding. Allies can both deter challengers and restrain partners, and as a result, can encourage peaceful behavior not only from adversaries, but from member states as well. Our study thus sheds new light on the role of military alliances as potential conflict management devices.