The United States is the only country in the world with a massive, globe-straddling, indefinite overseas military presence. There are about 800 U.S. bases with more than 270,000 troops in about 70 or 80 countries around the world. This is really a holdover from the Cold War that we kept in place, and in some areas expanded, despite the collapse of the Soviet Union.
Today, maintaining overseas bases isn’t justified by the threat of some powerful enemy state on the Eurasian continent. Instead, the general consensus in Washington is that this worldwide empire of bases makes the world more peaceful and more stable by deterring potential adversaries and reassuring allies. But a number of different factors contribute to global stability, and America’s military presence causes more problems than it solves.

These overseas bases have sometimes been referred to as the “American Pacifier.” By acting as the policeman of the world and discouraging aggression and arms races, we are supposed to pacify an otherwise conflict-prone international system.