RUTHFULLY YOURS

Although few realize it, the military is just as susceptible to fads and political correctness as any other government agency. Thus, in response to prodding from the executive branch, both the Air Force and Navy have announced plans to get half their fuel from “renewable resources” by 2020.

“We have already tested the F-18 Hornet on biofuels, the Green Hornet,” Secretary of the Navy Ray Mabus explained in a speech last year. “The biofuel it used was made from camelina, a member of the mustard family. . . . [T]he Marines, who are not known as leaders of the environmental movement, have embraced this wholeheartedly.”There are good reasons to consider powering forward bases and combat vehicles with something other than gasoline. Studies have shown that while the army can purchase gasoline for $1 a gallon, it costs $400 to deliver that gallon to the front in Afghanistan. In Iraq and Afghanistan, one soldier or civilian was killed for every 24 fuel convoys. But are biofuels the answer?

The military’s flirtation with green energy began a decade ago when the Department of Defense started taking advice from environmental guru Amory Lovins. In his 1976 book, “Soft Energy Path,” Mr. Lovins proposed getting one-third of our fuel oil from domestic crops. We could do this, he said, by building a distillery complex only 10 times the size of the combined beer and wine industries’ complexes.

In 2004, the Defense Department paid Mr. Lovins and his Rocky Mountain Institute to write “Winning the Oil Endgame,” a 300-page, four-color coffee-table book in which they proposed running the entire electrical grid on wind and sunshine, and using the backed-out natural gas and biofuels to power our transport sector.

Through all this work, however, Mr. Lovins has never bothered to calculate how much land would be needed to grow these crops. Using the figures he proposed with the grape and hops industries, it’s easy to estimate.

We would need an area three times the size of the continental United States to replace one-third of our oil requirements. These figures are confirmed in that we now employ one-third of the corn harvest—our biggest crop— to replace only 3% of our oil consumption. In “Winning the Oil Endgame,” by the way, Mr. Lovins predicated his scenario on inventing cars that get 125 miles to the gallon.

The armed services are charging ahead anyway, hoping to stay abreast of the latest style. Last October, the New York Times described a Marine company arriving in Afghanistan’s Helmand Province with all the latest green paraphernalia: portable solar panels, compact florescent light bulbs, solar tent shields that provide shade and electricity, and solar chargers for computers and communications equipment.

“[S]enior commanders have come to see overdependence on fossil fuel as a big liability,” wrote reporter Elisabeth Rosenthal, “and renewable technologies—which have become more reliable and less expensive over the past few years—as providing a potential answer. . . . The Marines are exploring . . . a small-scale, truck-based biofuel plant that could transform local crops, like illegal poppies, into fuel.”

But how many acres of poppies would be required? Lester Brown, the renowned environmentalist who has turned against biofuels, offers a vivid estimate. “The grain required to fill a 25-gallon SUV gas tank with ethanol will feed one person for a year,” he notes.

Any other form of renewable energy on the battlefield will face the same inherent limitation: the amount of land and space required to gather these very dilute energy streams. You may be able to recharge a laptop or heat a tent with a fold-up solar panel. But anything bigger would require a full-fledged array of gear that would easily be picked up by enemy radar. And what better way to give away your position than by erecting a three-story windmill?

As the Rand Corporation recently reported to the office of the Secretary of Defense, “[T]he use of alternative fuels offers the armed services no direct military benefit. . . .” and “the military is best served by efforts directed at using energy more efficiently in weapons systems and at military installations.”

Force protection should be the supreme goal of military strategy. We should do everything we can to limit the exposure created by moving fuel through combat zones. But let’s get real about the solutions. The job of the military is defending the nation.

Mr. James is a retired rear admiral and a former branch chief for the Central Intelligence Agency.

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