Since the 1940s, U.S. leadership of the international system has been justified, in part, by claims of a positive relationship between global stability and domestic prosperity. According to this argument, U.S. overseas security commitments that bolster stability in key regions of the world also generate economic benefits for the United States in the form of a stable international trading system that fosters growing trade in goods and services, unfettered access to global capital, and ultimately higher rates of economic growth at home. At the level of grand strategy, therefore, the nations expenditures on overseas security commitments may be at least partly offset by these economic benefits. The logic of this claim has long been accepted by policymakers and many academics, yet in practice, the economic returns from overseas security commitments have proved extraordinarily difficult to measure empirically. Today, there is intensifying debate over the resources devoted by the United States to its overseas commitments, with important voices calling for wholesale and unprecedented retrenchment in the face of mounting fiscal pressures. The question of whether and to what extent the United States derives economic benefits from its overseas security commitments is therefore increasingly salient.