It in fact makes little sense for the United States to bear most of the cost of securing the Gulf. In a 2010 study, Roger Stern, an economic geographer at Princeton University, found that from 1976 to 2007, the United States spent $6.8 trillion on protecting the oil flow from the Persian Gulf. “[O]n an annual basis the Persian Gulf mission now costs about as much as did the Cold War,” Stern wrote. This expenditure is even more striking given that, in recent years, the United States has received less than 10 percent of Gulf hydrocarbons. In effect, Washington has given the major importers of Gulf energy (i.e., China, India, and Japan) a free ride when it comes to their energy security.