Pork, parties, and priorities : partisan politics and overseas military deployments

Since the end of WWII, the United States has maintained a sizable military presence around the world. As one of the main mechanisms that the US uses to exercise its military power abroad, it is a defining characteristic of the international order. This issue has gotten much less attention in the field of International Relations than is warranted by its importance, and the attention that it has gotten has been largely focused on strategic issues and the demand for US military forces. To this, I add the domestic politics within the United States that determine the supply of American military forces that are available for use abroad. Because of the economic importance of US forces to congressional districts, for Members of Congress to agree to send forces overseas, they must be compensated in a way that fits their distributional preferences. Agreement on the means of compensation is easier to find when a Member’s copartisans control both branches of the US government, and when politicians on both sides of Pennsylvania Avenue agree on the strategic priority that demands the deployment of US military personnel overseas. Using time-series cross-sectional models, I show that, in addition to strategic considerations, the President’s party strength in Congress and the proportion of moderates in the Senate, are key determinants of US deployment outcomes. Higher proportions of the President’s copartisans and moderates in Congress are correlated with more forces being sent overseas. In addition, I examine case evidence from Kosovo, the Middle East, and Eastern Europe that demonstrates the causal mechanisms. In the end, this is an important contribution, because it adds an important determinant of deployment patterns to the literature on the nature of the US military presence around the world. It provides a statistical model for predicting troop levels around the world, and it solves existing puzzles in deployment patterns that arose through a sole focus on strategic considerations.