Much of the empirical literature suggests that outside interventions tend to lengthen the expected duration of civil wars; conversely, the policy community often acts as if it holds the opposite expectation for the outcome of intervention. The authors argue that the divergence can be found in how models of intervention are specified in the literature. They propose a model with two novel contributions. First, they incorporate mediations as the key to resolving the strategic problems that the civil war parties face. Second, they account for the decaying effect of interventions over time. Their results suggest that diplomacy is critical for understanding the duration of civil conflicts. They find that mediation has a dramatic effect on the expected duration of a civil war and that when controlling for diplomatic efforts, economic interventions can also reduce the expected duration.

Recent research in the civil war literature has focused on how and when external actors intervene. However, to date, systematic data have not existed on diplomatic efforts in conflict management. This article fills this gap and introduces a dataset on 438 diplomatic interventions in 68 conflicts stretching from 1945 to 1999. The authors briefly outline previous research on third-party interventions in civil wars, describe the dataset in some detail, including some initial patterns in the data, and describe how this dataset contributes to research into conflict processes. The authors also demonstrate how diplomatic interventions can be incorporated into other research agendas by merging this dataset with Doyle & Sambanis's peacekeeping data and replicating their analysis to examine the role of external diplomacy on peacebuilding success. These data on interventions, moreover, can be merged with commonly used datasets on intrastate conflicts, which promises a wide range of application in civil war studies. Developing a greater understanding of when and how civil wars end, scholarship needs to take into account efforts to arrive at diplomatic solutions. And if, as the results demonstrate, externally driven diplomacy facilitates the termination of civil wars, then the policy implications are quite important.

While the extant literature on the un peacekeeping missions has considered the dynamics of institutional decisionmaking, relatively less attention has been paid to how states choose the civil wars in which they are going to intervene. In this article, I compare state and IgO decisionmaking in civil war intervention and claim that states make strategic decisions and consider the behavior of other third-party states to judge the costs and risks associated with intervention. event history analysis results for the post-WWII period suggest that the timing of civil war intervention is closely associated with the war's intervention history. States become hesitant and wait for longer periods to take action in civil wars in which interventions that failed to influence combatant behavior have been attempted by other states. Civil wars that survive despite heavy third-party involvement discourage other states from undertaking intervention efforts.

With growing attention to peace-building in civil wars, scholars have increasingly focused on the role that international and regional organizations play in conflict resolution. Less attention has been paid to unilateral interventions undertaken by third-party states without the explicit consent of organizations and to the impact of unilateralism on how long civil wars last. In this article, we claim that unilateral interventions exert a cumulative impact on civil wars depending on interveners' interrelations. States with a cooperative rapport have an easier time in bringing civil wars to an end though they act unilaterally and follow their interests in the civil war environment, whereas states that compete for influence over war combatants prolong the fighting. Analysis results from post-1945 civil wars support our expectations and show that interveners supporting opposing sides of the war increase war duration. On the other hand, third-party states bandwagoning on the same side of a civil war are effective in stopping the fighting only when the intervening parties share similar preferences.