About two thirds of the 22,000 Humvees in Iraq now have some type of armor, and in November the Senate appropriated $344.3 million to add more steel to the Hummer fleet. Electronic jammers are being used to thwart IEDs detonated by radio. One of the newest counter-IED technologies is known as the Buffalo—a twenty-seven-foot mine-destroying vehicle with solid rubber tires and a remote-operated steel arm. It weighs more than fourteen Toyota Camrys and gets about four miles per gallon.
Votel told me recently that some of the countermeasures have been effective, and that the number of casualties caused by each IED has declined. But he concedes that the overall casualty rate is still climbing, and that the insurgents are changing their tactics. "This is a very, very adaptive enemy," he says. "We clearly recognize that there's a very difficult road ahead of us."
The insurgents have responded to heavier armor by building larger and more sophisticated mines. Last August fourteen Marines were killed near Haditha, in western Iraq, when their moderately armored amphibious-assault vehicle was hit by an IED fashioned from three land mines. The Iraqis have also begun using shaped charges that fire armor-piercing conical projectiles. As jammers proliferate, cell-phone detonators are being replaced by pressure switches and other techniques. And as bomb makers share their knowledge by circulating videos and other instructional materials, more IEDs of all types are being planted and detonated. Many military analysts and active-duty soldiers doubt that the threat posed by IEDs can be neutralized anytime soon.
The growing use of IEDs is forcing America's military strategists to rethink centuries of military doctrine holding that in warfare, mobility equals dominance. Votel told me that given the success that IEDs have had against America's fleet of motor vehicles, the Pentagon may need to switch to more foot patrols. An intelligence analyst working on the IED problem agreed, saying, "The answer to the IEDs is to leave the vehicles. It's obvious. It's the only choice." But such a move would expose U.S. soldiers to other risks, including snipers. And the December detonation of an IED in Fallujah, killing ten Marines on foot patrol, shows that soldiers will remain vulnerable to IEDs whether on foot or behind the wheel. As long as the insurgents can use IEDs to inflict damage on U.S. soldiers without ever engaging them directly, they will have a tactical advantage. "Our whole military is based on the idea of overwhelming firepower put on targets," says William S. Lind, a noted military theorist who has written extensively on asymmetric warfare. "But that doesn't work in this type of conflict. We are fighting an enemy that has made himself untargetable." Therefore, Lind says, the insurgents can continue fighting the American military in Iraq indefinitely—regardless of how many U.S. troops are deployed or how quickly they are massed.
IEDs also create fear and uncertainty—sensations that Lawrence exploited in fighting the Turks. In Seven Pillars he wrote that after his initial success at planting mines, the technique was quickly adopted by his fellow warriors. Over a period of four months his bomb makers destroyed seventeen locomotives, after which "traveling became an uncertain terror for the enemy."
Fear and uncertainty, of course, ultimately breed mistrust. That may be the most damaging aspect of the IEDs: they prey on American minds, making soldiers suspicious of the local population and ultimately isolating them.
For Lind and other military theorists, the IED problem in Iraq is insoluble no matter how much time or money is spent. "If we can't engage the enemy," he says, "what do we do? The answer is, we lose."