Sen. John McCain reinforced his bipartisan credentials Thursday evening by sounding as confused as the Democrats on the nation’s assumed need for “energy independence.”

In his acceptance speech at the GOP convention in St. Paul, McCain pledged federal support for alternative energy so the United States can reduce the amount of energy it imports from abroad. “When I’m president,” McCain told cheering delegates, “we’re going to embark on the most ambitious national project in decades. We are going to stop sending $700 billion a year to countries that don’t like us very much. We will attack the problem on every front.”

He then pledged his support for more offshore drilling, nuclear power plants, wind, tide, solar and natural gas.

Whoa! Before we embark on a project that could cost tens or hundreds of billions of dollars, let’s get the facts straight. Specifically, where did that $700 billion number come from?

That is far more than what we pay for imported energy. In 2007, Americans spent less than half that amount—$319 billion—for imported energy of all kinds, including oil and natural gas. Even with higher energy prices in 2008, our total bill for imported energy this year will be nowhere near $700 billion.

Contrary to popular perception, most of our oil imports come such friendly countries as Canada, Mexico, Colombia, Brazil, and the United Kingdom, or from more neutral suppliers such as Iraq, Kuwait, Nigeria, Angola, Chad and Congo (Brazzaville). Only a third of our imported oil comes from the major problem countries of Saudi Arabia, Venezuela, Algeria, Ecuador and Russia. We don’t import any oil directly from Iran. [You can check out the latest Commerce Department figures here.]

The $700 billion that Sen. McCain probably had in mind is America’s total trade balance, known as the current account. Last year, Americans rolled up a $731 billion current account deficit with the rest of the world. That account includes not just energy but also manufactured goods, farm products, services, and income from foreign investments.

The current account deficit is not driven by energy imports but by the underlying level of savings and investment in the U.S. economy. We run a current account deficit because, year after year, more is invested in the American economy than Americans save to finance that investment. Foreign capital fills the gap, and the resulting net inflow of foreign investment more or less directly offsets the gap between what we import and what we export.

If the federal government dramatically increases spending on alternative energy, as Sen. McCain and his Democratic opponent both seem to want, the result will be a bigger federal budget deficit, a smaller pool of domestic savings, more foreign capital flowing into the United States, and an even larger current account deficit.