The United States was more reliant on Middle East oil imports in 2012 than in previous years, U.S. Energy Department figures indicate, emphasizing how important the volatile region remains for Washington.

The Financial Times observed that the growth of oil imports from the Persian Gulf, where the United States and its allies are confronting an expansionist Iran, indicates "the United States will continue to play a critical security role in the region."

In November 2012, the International Energy Agency, the West's energy watchdog, announced that, with the unlocking of vast oil and shale natural gas reserves, the United States was headed for virtual energy self-sufficiency and would overtake Saudi Arabia as the world's leading oil producer by 2020.

The geostrategic implications of that are immense. The United States would no longer be dependent on despotic gulf monarchies and might no longer consider it necessary to spend billions of dollars protecting the region and its sea lanes from Iran by constantly deploying large forces there.

The Financial Times observed that while U.S. domestic production has risen sharply over the last year and could transform the country into a net exporter by around 2030, it remains reliant on gulf oil supplies.

U.S. Energy Department statistics indicate that by the end of November, U.S. crude oil imports from Saudi Arabia stood at 450 million barrels -- more than it imported from the kingdom in the whole of 2009, 2010 and 2011.

"For the first time since 2003, Saudi imports accounted for more than 15 percent of total U.S. oil imports," the Financial Times observed.

"The gulf as a whole accounted for more than 25 percent, a nine-year high."

By the end of November, amid "unusually strong demand ... Kuwait had shipped more oil to the U.S. than in any year since 1998."

Annual figures to be expected shortly from the U.S. Energy Department for 2012 are expected to confirm the information.

How long U.S. dependence on gulf oil will continue isn't clear. It's likely to be a few years yet, since many of its refineries are geared to process the heavy varieties of crude that come from the Persian Gulf, rather than the lighter, high-quality crude produced from the vast shale fields in North Dakota and Texas.

"So while imports of light crudes from countries such as Nigeria have fallen dramatically, demand for gulf crudes has not," the Financial Times noted.

As the United States moves toward self-sufficiency in oil production, which the IEA estimates will happen in 2035, and imports of gulf oil start to diminish, China and India, the emerging economic titans in Asia, will be rivals for Middle Eastern and African oil.

If the United States scales down, or eventually wraps up, its military deployment in the Middle East, China and India could well find themselves competing for the region's energy supplies.

The Indian Ocean, the maritime corridor between the gulf and Asia, could well become a contested zone.

China and India are already building up their naval forces and their long-range capabilities.

All this will dramatically change the United States' strategic outlook.

"It is still far from clear how this shift will affect the strategic balance in the Persian Gulf and the Middle East and U.S. engagement -- especially given the rising tension over Iran's nuclear program and the instability throughout the region," observed veteran energy expert Daniel Yergin.

"The debate about these considerations will be stirred by America's future fiscal negotiations. But the question will not really be addressed until the crisis with Iran is resolved ...

"The significance of the rebalancing of world oil production goes beyond the Middle East to that most critical 21st-century relationship -- the U.S. and China.

"Beijing will see an increasing share of its imports coming from the Middle East," wrote Yergin, author of "The Prize - the Epic Quest for Oil, Money and Power," which won the 1992 Pulitzer Prize for non-fiction.

"At this point, China is de facto relying upon the U.S. to undergird regional security and to maintain the freedom of the sea lanes on which it depends for its own oil imports.

"All this will require China and the U.S. to develop a more explicit understanding and a framework for collaboration on oil security."