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.

Does the shadow of war decrease trade? I examine the influence of conflict on bilateral trade and argue that trading firms' expectations of armed conflict, both within and between nation-states, should decrease trade along with armed political violence. By assuming that firms care about future profits and assess the likelihood of a domestic or interstate conflict in the future that could disrupt trade, I argue that increasing the expectation of a domestic or interstate conflict raises the transportation, transaction, and production costs of trade. Empirically, contemporaneous trade levels should be negatively related to trading firms' beliefs about the likelihood of domestic and interstate conflicts in the future. Statistical tests, using bilateral trade data from 1984 to 1997, show that expectations of domestic or interstate conflict, in addition to violent armed conflicts, are negatively correlated with bilateral trade levels. Theoretically and empirically, this research advances our understanding of the trade-conflict relationship by demonstrating how trading firms' expectations about future conflict reduce bilateral trade levels.Does the ''shadow of war'' decrease trade? Previous research explains the inconsistent influence of militarized interstate conflict on bilateral trade by invoking the rational-expectations hypothesis. Rational traders may anticipate interstate conflict by observing hostility prior to military conflict and lessen their commercial exchange between countries when conflict is likely (Morrow, Siverson, and Tabares 1998;Morrow 1999). Li and Sacko (2002) find indirect support for the rational expectations claim; they find that militarized interstate conflicts do not decrease bilateral trade when the probability that conflict will occur is high. While the rational-expectations hypothesis suggests that firms' beliefs about the likelihood of conflict should be a significant determinant of observed patterns of international trade, direct evidence of the influence of the ''shadow of war'' on bilateral trade has not been shown empirically. I examine how firms' expectations of armed conflict reduce trade and evaluate how much influence these expectations have on bilateral trade levels.

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.

Theories of international political influences on trade maintain that shared alliance commitments affect bilateral commercial exchange. The most prominent of these suggests that trade produces a security externality threatening states, but that a military alliance alleviates these concerns, leading to greater trade among allies. Yet past empirical analyses produce inconsistent findings with respect to the effect of military alliances on bilateral trade levels. This article presents a new argument to explain the inconclusive findings in previous studies. The potential increase in military power from efficiency gains through trade is a positive security externality only when a commitment to defend one's alliance partner exists. In essence, cooperative security agreements that require states to give military assistance to each other if attacked (i.e. defense pacts) will lead to greater trade among their members than agreements in which the members promise neutrality, non-aggression, or consultation. The analysis distinguishes alliances that include commitments of defense from those that do not, and uses two different sources of alliance data to examine the effects of defense pacts on trade levels between major powers from 1885 to 1990. The results demonstrate that defense pacts are associated with higher trade among alliance members, but that trade between members of non-defense pacts is statistically indistinguishable from trade between non-allies. This article recognizes that a link between economic and security issues exists and emphasizes their mutual relationship.

We argue that certain provisions of alliance treaties can signal credible commitments to a peaceful relationship among members and establish institutional mechanisms that promote the settlement of disagreements through peaceful negotiation. Nonaggression, peaceful dispute settlement, military institutionalization, and permanent organization provisions should increase the duration of peace between alliance members; we test our hypotheses with a duration model. The analysis generally supports our expectations except that alliances that create permanent organizations, even those specifically established to arbitrate disagreements, are associated with shorter durations of peace. We conclude with some implications of our argument for the study of military alliances and international institutions more broadly. C ompeting theoretical perspectives in the quantitative study of conflict among allies predict that intra-alliance conflict will be either more or less prevalent, with empirical evidence in support of each perspective. The inconsistency in both theory and evidence may be a consequence of interstate conflict scholars primarily focusing on the deterrent properties of alliances through capability aggregation. 1 Snyder (1997), espousing a realist theory of alliance formation, explicitly states that the outward looking nature of alliances makes alliances different than other institutions. Such a perspective leaves little room for placing alliances within the larger set of international institutions as we think about international conflict processes. With attention focused on the external effects of alliances, it is not surprising that quantitative studies of alliances and conflict have only begun to examine the conflict process within alliances.This gap in the alliance-conflict literature is particularly vexing because of the volume of theoretical and qualitative work in international relations that incorporates alliances into the broader institutional picture. Building upon on the themes recognized by diplomatic historians such as Schroeder (1976), these scholars explicitly consider the formation and maintenance of international institutions (including alliances) to address security concerns with fellow members (e.g., Krebs 1999;Lake 1999;Weber 1997;Weitsman 2004). Therefore, a more complete understanding of the relationship between alliances and military conflict requires investigating whether or not alliances that form are successful at maintaining peace. We contribute to the literature on alliances and conflict by investigating the relationship between alliance treaty obligations and the duration of peace (i.e., the period of time between alliance formation and military conflict) between signatories. In other words, our argument concerns the extent to which alliances are effective at reducing military conflict once they are established.As it turns out, many alliances incorporate institutional mechanisms designed to promote peace. We argue that states design alliances in part to regulate internal political dynamics...