The U.S. military’s global presence is vast and costly. More than one-third of U.S. troops are currently based abroad or afloat in international waters, and hundreds of bases and access agreements exist throughout the world. At the beginning of the 21st century, the government pushed to expand this presence through a variety of mechanisms. Yet the Department of Defense’s budget presentations lack enough detail to make it possible to know the precise cost. The budgets don’t break down the numbers, for example, on maintaining bases at home and overseas.