But long-term U.S. military basing has failed to stop Iran from attacking Persian Gulf shipping, even as it has discouraged investment in a more robust global oil transportation network, setting the stage for today’s oil price spike worries. As the Iran crisis plays out, the United States has better options than doubling down on Mr. Carter’s approach, but they require us to understand and correct America’s unique vulnerability: The country is more exposed to oil price shocks than any other major power, including China.