Beyond the Target State: Foreign Military Intervention and Neighboring State Stability

Despite the abundance of research on the consequences of foreign military intervention for target countries, scant research has been devoted to the possible regional externalities of intervention. This article examines whether large-scale armed operations affect the likelihood of civil conflict onset in countries neighboring the target of intervention. We posit that interventions against the target regime reduce the government's ability to maintain full control over the entire national territory by diminishing its coercive and administrative capacity. This might, in turn, result in safe haven possibilities for neighboring rival groups in the target and facilitate the transnational spread of arms and other illicit activities that increase the risk of civil conflict onset in the contiguous countries. Armed interventions supportive or neutral toward the target state, on the other hand, bolster the government's coercive capacity and mitigate ongoing crises in the target. Such armed intrusions might therefore undermine the likelihood of internal armed conflict in neighboring countries triggered by the factors associated with “bad neighborhoods”: safe haven possibilities, transnational spread of arms, and refugee flows. To substantiate these claims, we use time-series, cross-national data for the 1951--2004 period. Results indicate that hostile interventions increase the probability of civil conflict onset in connected countries while supportive interventions have a regional pacifying effect, reducing the likelihood of domestic unrest in countries neighboring the target state. Neutral interventions, on the other hand, are unlikely to have any discernible effect on regional stability. Further, the primary motive of intervention, whether for humanitarian or other purposes, has no statistically significant impact on the stability of neighboring countries.