Empires come and empires go—and their collapse, says financial historian Niall Ferguson, is often precipitous (Foreign Affairs, March/April). For example, the economic and military might of the British Empire was sharply reduced by the time of the Suez Canal crisis in 1956—just a decade after one of the empire’s shining moments, the defeat of the Axis powers. The collapse of the Soviet empire was even swifter—it disintegrated in less than five years, largely because the Soviet Union’s economy was floundering and because so much of its industrial output was devoted to the military.
Ferguson’s analysis is fair warning to the United States. The collapse of the U.S. empire will be partly a numbers game, Ferguson says, the result of “the slow march of demographics,” as fewer people in the U.S. workforce are available to pay the taxes that support the health and retirement benefits promised to an aging population.