| Intervention, Morgenthau (1967) notes, is "as ancient and well-established an instrument of foreign policy as are diplomatic pressure, negotiations and war." Like all foreign policy decisions, intervention decisions are strategic: they are made in anticipation of the actions of other actors. This dissertation analyzes how international and domestic strategic environments affect military intervention decisions.; When deciding whether to intervene, states consider the anticipated actions of other potential interveners. If major powers have conflicting policy preferences, they have incentives to intervene preemptively to eliminate the possibility of future interventions by rival powers. Given this, major powers should be more likely to intervene in their spheres of influence when another power provides an external threat. An historical examination of U.S. intervention behavior in the Caribbean Basin supports this argument.; Common sense suggests that major powers should be more likely to pursue joint intervention when their preferences are most similar. However, empirically, states are least likely to intervene jointly when they have the same preferences over the issues at stake. The reason for this unexpected finding is quite intuitive. When states agree over policy, they face a free rider problem. Therefore, a state is more willing to join or counter an intervention as its preferences with the initial intervener diverge.; In addition to the anticipated actions of other external actors, potential interveners also consider the domestic strategic environment in the target state when deciding whether to intervene. Conventional wisdom suggests that interventions in civil conflicts should increase the probability that the targeted side will win. However, while this is the case for rebel groups, the same is not true for governments. The explanation for this surprising finding becomes clear once one considers the decision of an intervener. Since interveners want to impact the outcomes of civil conflict, government- and rebel-biased interventions will be more likely when the government is facing a stronger rebel group. Given that government-biased third parties intervene in the "toughest" cases, empirically they appear be less effective than interventions on behalf of the rebels. |
