One rationale for ethanol production in the U.S. is increased energy independence, from shifting supply from oil imports to domestic sources. Ethanol production requires significant energy, and current U.S. production derives most of that energy from domestic coal, natural gas and other non-oil sources.Because in 2006, 66% of U.S. oil consumption was imported, compared to a net surplus of coal and just 16% of natural gas (2006 figures), the displacement of oil-based fuels to ethanol produced a net shift from foreign to domestic U.S. energy sources. Currently the USA is an net oil exporter in 2011 The U.S. exported more gasoline, diesel and other fuels than it imported in 2011 for the first time since 1949.
And becoming an oil exporter wasn't all done by increasing reliance on our internal oil resources there is more than one way to skin a cat. Drilling is one answer but not the only answer to USA energy independence.
Using less gas obtained from imported oil is one way, improved gas mileage vehicles, ethanol, transportation accounts for a lot of our oil usage. But alternate energy sources, wind, water, solar, nuclear, thermal, natural gas, coal, and new renewable energy sources, ethanol, biofuel, and biomass also help us become energy independant.