The United States maintains more than 2,000 military bases or installations in other countries. What determines whether those countries agree to host them? Gresh seeks to answer this question by focusing on a half century of negotiations that Bahrain, Oman, and Saudi Arabia—all of which host U.S. forces—have conducted with the United States. Gresh argues that if a foreign government perceives internal security threats as paramount, it will be reluctant to host U.S. bases. But when external security threats prevail, governments will tolerate (and even welcome) the presence of American forces. His analysis does not sufficiently address the fact that some threats are both internal and external: consider, for example, Iran’s support for Shiite minorities in the Gulf Arab kingdoms and Yemen. Gresh also does not explore the dilemmas faced by Washington caused by establishing U.S. bases in places such as Bahrain, where repressive regimes abuse segments of their own populations—perhaps because that kind of political liability does not seem to trouble the American electorate.