In the early days of the oil industry, the U.S. quickly established dominance as the world’s most important producer and consumer of petroleum. But over time, depletion in the U.S. and discoveries abroad caused U.S. dominance of the petroleum industry to fade. Although the U.S. remained the world’s largest consumer of petroleum, it became increasingly dependent on foreign oil.
It became clear many years ago that U.S. dependence on other countries for petroleum was a national security issue. The issue came to a head in 1973, when various members of the Organization of Petroleum Exporting Countries (OPEC) initiated an oil embargo against the United States and certain U.S. allies.