While the United States consumes roughly 19 million barrels of oil a day, mostly to power its 200 million automobiles, it produces only about 8 million barrels (or 42 percent) of that total domestically. The other 58 percent -- some 11 million barrels a day -- of our oil has to be imported from other countries.

Although the Middle East remains a principal oil supplier for the U.S. market, in recent decades other parts of the world -- West Africa and Central and South America -- have become vitally important as sources of petroleum. Today, three non-Middle East nations -- Mexico, Venezuela and Nigeria -- combine to provide the United States with almost as much oil as the Persian Gulf region provides. But overall world oil reserves outside of the Middle East appear to be limited, so over the longer term, the United States expects to remain deeply dependent on oil from the Persian Gulf.

Meanwhile, the global demand for oil is growing all over the world, with India, China and South Korea in particular fueling recent sharp increases in demand. This means that inevitably there will be greater competition among nations for what is by any measure a diminishing world oil supply. This is one reason underlying the strategic deployment of U.S. military resources in and around the Middle East.

The following charts summarize key aspects of the current global oil business.