In his 1980 State of the Union address, which came in the wake of the oil shocks of 1973 and 1979, U.S. President Jimmy Carter described in grave terms the risks of losing access to Middle Eastern oil. “An attempt by any outside force to gain control of the Persian Gulf region will be regarded as an assault on the vital interests of the United States of America,” he said. “Such an assault will be repelled by any means necessary, including military force.” That pledge became known as the Carter Doctrine, and it has remained a defining feature of U.S. Middle East policy ever since.
At the time of Carter’s pronouncement, the United States relied heavily on oil imports to power its economy, and 29 percent of that oil came from the Persian Gulf. Even two decades later, little had changed: in 2001, the United States still imported 29 percent of its oil.