Dissertation: The Initiation and Effectiveness of Multi-Coalition Peace Operations

Committee: Alexander Thompson (chair), Amanda Lea Robinson, Bear F. Braumoeller

In this dissertation I investigate an approach to conflict management that I refer to as hyperlateral intervention. These are interventions in conflict carried out by two or more multilateral coalitions, operating at the same time or one after another, with the goal of providing peace. These multi-coalition interventions did not occur in the first few decades of international peacekeeping – it wasn’t until the early 1990s, after the Cold War came to an end, that we see the first instances of hyperlateral intervention. The model has grown in popularity since then, with close to half of peace operations established since the early 2000s having been carried out by two or more separate coalitions. Despite the prominence of this model, we know very little about why hyperlateral interventions are initiated, and whether and under what conditions these operations are effective.

This dissertation contributes to filling this gap in the literature, first by defining hyperlateral intervention, identifying the universe of cases of hyperlateral intervention, and providing a historical account of the emergence and the growth of this intervention model. I then provide a theoretical framework for considering why hyperlateral operations are created and when they are effective.

This framework begins by arguing that states and intergovernmental organizations (IGOs) are interested in dividing the labor of peace operations when operational needs exceed what a single coalition is able and willing to provide. Because different actors carrying out peace operations have different sets of comparative advantages and disadvantages, I argue that intervenors have the potential not just to divide the cost and labor of intervening, but to efficiently divide their labor by taking advantage of those differences in comparative advantage. Then, motivations beyond operational effectiveness, including a logic of path dependence, and state and IGO interests in securing power and reputation, are introduced. I argue that hyperlateral interventions are more likely to be effective when intervenors have complementary comparative advantages. Furthermore, I hypothesize that operational effectiveness depends on the level of communication and coordination among intervening parties. Absent such coordination, intervenors may inadvertently act inefficiently, or even at cross purposes.

To examine these arguments, I analyze a series of cases of hyperlateral intervention, tracing how involved coalitions came to intervene, how international actors influenced one another as interventions were established, and security outcomes both during and after intervention in each case. This case study approach compares the predictions that my theoretical arguments would make about how states and organizations act, and how effective the intervention should be in providing peace, to what we actually observe in these cases.

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Weihua Li,  Aisha E. Bradshaw, Caitlin B. Clary, and Skyler J. Cranmer. “A Three-Degree Horizon of Peace in the Military Alliance Network.” Science Advances Vol. 3, No. 3: e1601895 (01 March 2017). 

See coverage of this study at Nature Human Behavior, HuffPost, and ScienceDaily, as well as our write-up for general audiences at The Conversation.

Abstract: States form defensive military alliances to enhance their security in the face of potential or realized interstate conflict. The network of these international alliances is increasingly interconnected, now linking most of the states in a complex web of ties. These alliances can be used both as a tool for securing cooperation and to foster peace between direct partners. However, do indirect connections—such as the ally of an ally or even further out in the alliance network—result in lower probabilities of conflict? We investigate the extent to which military alliances produce peace between states that are not directly allied. We find that the peacemaking horizon of indirect alliances extends through the network up to three degrees of separation. Within this horizon of influence, a lack of decay in the effect of degrees of distance indicates that alliances do not diminish with respect to their ability to affect peace regardless of whether or not the states in question are directly allied. Beyond the three-degree horizon of influence, we observe a sharp decline in the effect of indirect alliances on bilateral peace. Further investigation reveals that the community structure of the alliance network plays a role in establishing this horizon, but the effects of indirect alliances are not spurious to the community structure.