This report reviews data that the Administration has provided to Congress on the costs of U.S. forces based abroad and on the value of host nation support contributions. It analyzes the data in order to assess potential defense budget savings from measures now under congressional consideration. The report concludes that, because of shortcomings in the data, estimates of savings in the U.S. defense budget from increased host nation contributions are often overstated. Some commonly accepted assertions frequently cited in the congressional burdensharing debate, therefore, are of doubtful validity.