Some of the rise in consumption is due to the insurgents' use of improvised explosive devices, which account for about 30 percent of all American combat deaths since the occupation began. As John Pike, the executive director of GlobalSecurity.org, told me, "This is a war of convoy ambushes and car bombs. There is no front line." Perhaps hundreds of American vehicles have been destroyed by IEDs (the exact number is classified), and hundreds of soldiers—many of them guarding convoys—have been killed or injured by them. (And more than sixty-five private contractors are known to have been killed by convoy attacks or IEDs since July of 2003.) Cheap, easy to use, and highly effective, IEDs have forced the Americans to add armor to their fleet of Humvees in Iraq. A fully armored Humvee weighs more than five tons—and requires a larger engine and heavier suspension than the non-armored model. The Army also recently allocated more than $500 million to add armor to its utility trucks.
The added armor will help protect U.S. soldiers from IEDs and snipers—but it also means higher fuel consumption for their vehicles. Which means, in turn, that more tanker trucks will have to be driven into Iraq—and those trucks will provide more targets for the insurgents, who have become skilled at attacking them. It's difficult to guard them all. When insurgents see that American patrols are increasing in one region, they can quickly and easily shift their attacks—on fueling stations, pipelines, truck convoys, refineries—to another region.
It's a vicious cycle: attacks on convoys produce a need for more armor, which produces a need for more fuel, which produces larger convoys, which produce more targets for attack. Over the past six months the Army and the Air Force have had to specially train more than 1,000 additional soldiers to perform convoy security. One tank commander, who returned from Iraq last spring, told me that he had been so concerned about his supply lines that he had stationed sentries at one-mile intervals along the highway in his sector.
Logistics is an old and critically important issue in war. During World War II the German general Erwin Rommel's Afrika Korps was stymied in North Africa by a shortage of fuel for its tanks. A lack of gasoline also halted the gallop across France of General George Patton's Third Army in the summer of 1944. The Third Army had about 400,000 men and used about 400,000 gallons of gasoline a day. Today the Pentagon has about a third that number of troops in Iraq—yet they use more than four times as much fuel.
Given that the longer the fuel supply lines, the greater the vulnerability for our military, logic would suggest we try to reduce our fuel requirements. But over the past several decades the Pentagon has bought billions of dollars' worth of tanks, trucks, and other vehicles with little or no consideration to their fuel efficiency. In decades past, U.S. Army logisticians assumed that 50 percent of the tonnage moved onto a battlefield was ammunition, 30 percent was fuel, and the rest was food, water, and supplies. Today the fuel component may be as high as 70 percent, according to a study done in 2001 by the Defense Science Board.