This dissertation explores two interrelated puzzles about external intervention and internal war. The first asks why rebels, governments, and third party interveners often continue to invest in costly and protracted conflicts rather than sue for peace and a negotiated settlement. The second considers the consequences of these behaviors for temporal variation in the average duration and global prevalence of civil wars. A central finding that emerges concerns the critical role of competitive intervention-two sided, simultaneous military assistance from different third party states to both government and rebel combatants-in the dynamics and intractability of civil wars across time and around the globe. Developing a generalizable theory of competitive intervention, the dissertation explains the distortionary effects this form of external meddling has on domestic bargaining processes, describes the unique strategic dilemmas it entails for third party interveners, and links its varying prevalence to international systemic change. In doing so, it moves beyond popular anecdotes about "proxy wars" by deriving theoretically-grounded propositions about the strategic logics motivating competitive intervention in civil wars. It also uncovers a heretofore overlooked feature of this form of intervention-namely, that "not losing" is often more important than "winning" from the perspective of third party interveners under the shadow of inadvertent escalation. The theory is tested with a mixed-method design that combines statistical analyses of all civil wars fought between 1975 and 2009 with detailed case studies of competitive intervention in Angola (1975-1991) and Afghanistan (1979-1992). The dissertation's theoretical and empirical results shed new light on the international dimensions of civil war, address ongoing debates concerning the utility of intervention as a conflict management tool, and inform policy prescriptions aimed at resolving some of today's most violent internal conflicts.

This book identifies the conditions under which foreign countries intervene in civil wars, contending that we should consider four dimensions of civil war intervention. The first dimension is the civil war itself. The characteristics of the civil war itself are important determinants of a third party’s decision making regarding intervention. The second dimension is the characteristics of intervening states, and includes their capabilities and domestic political environments. The third is the relationship between the host country and the intervening country. These states’ formal alliances and the differences in military capability between the target country and the potential intervener have an impact on the decision making process. The fourth dimension is the relationship between the interveners. This framework of four dimensions proves critical in understanding foreign intervention in civil wars. Based on this framework, the model for the intervention mechanism can reflect reality better. By including the relationships between the interveners here, the book shows that it is important to distinguish between intervention on the side of the government and intervention on behalf of the opposition. Without distinguishing between these, it is impossible to consider the concepts of counter-intervention and bandwagoning intervention.

This volume brings together expert case studies on a range of experiences of third-party interventions in civil wars. The chapters consider the role of a variety of organisations, including the United Nations, NATO, the European Union, the Shanghai Cooperation Organisation, the Organisation of the Islamic Conference, the African Union, and the Organization of American States. Each case study features a presentation and analysis of empirical data in two dimensions: the organisation’s general capabilities to carry out intervention in civil wars and, specific to one particular intervention, the conflict context in which it happened. This serves two purposes. First, to offer insights into the dynamics of each individual case and helping us understand the specific outcome of an intervention effort, i.e., why did a mission (partially) succeed or fail. Second, it enables us to make real comparisons between the cases and draw policy-relevant conclusions about the conditions under which military, civilian and hybrid intervention missions are likely to succeed. This book was originally published as a special issue of Civil Wars.

The 2013 debate over whether the United States should intervene in the Syrian conflict raised important questions regarding the benefits countries receive when they intervene in civil wars, and how those benefits are distributed to the citizens of the intervening country. To address these lingering questions this book offers readers a comprehensive examination of the intervention process, examining the decision to intervene, what motivates states, and how their intervention shapes the conflict process. Most, importantly, the book examines how states benefit from their interventions and the distribution of intervenor benefits. Specially two questions are addressed: What are the benefits of intervention for intervening countries? And, how are benefits distributed within the intervenors society? Using evidence compiled from three case studies (El Salvador, The Philippines, and Sri Lanka), this book examines what motivated states to intervene, how they intervened, what they got from their intervention, and how the benefits of the intervention were distributed among the public. Arguing that foreign policy and security decision making is isolated from the general public, this book argues that citizens gain little from indirect interventions into civil wars.

The duration of large-scale violent civil conflict increases substantially if the society is composed of a few large ethnic groups, if there is extensive forest cover, and if the conflict has commenced since 1980. None of these factors affect the initiation of conflict. And neither the duration nor the initiation of conflict is affected by initial inequality or political repression.

By analytically decoupling war and violence, this book explores the causes and dynamics of violence in civil war. Against the prevailing view that such violence is an instance of impenetrable madness, the book demonstrates that there is logic to it and that it has much less to do with collective emotions, ideologies, and cultures than currently believed. Kalyvas specifies a novel theory of selective violence: it is jointly produced by political actors seeking information and individual civilians trying to avoid the worst but also grabbing what opportunities their predicament affords them. Violence, he finds, is never a simple reflection of the optimal strategy of its users; its profoundly interactive character defeats simple maximization logics while producing surprising outcomes, such as relative nonviolence in the 'frontlines' of civil war.