'You can't armor your way out of this problem'

At the IED task force, Votel again contacted the Israelis, who in June had sent several counter-IED technologies to Yuma Proving Ground in Arizona for testing, which was inconclusive. "I know you've got some systems on this," he told an Israeli officer. "Can we get them?"

An Army lieutenant colonel again flew from Washington to Tel Aviv. Soon a pair of vehicle-mounted microwave devices, called Dragon Spike, arrived in Iraq aboard an Air Force jet, freshly painted and with all Hebrew markings removed. Field tests again showed mixed results.

Meanwhile, soldiers in the field pursued their own solutions. Because a passive infrared sensor reacted to heat signatures, one inventive trooper proposed mounting a giant hair dryer on a bumper to blow hot air in front of the vehicle. Another took a toaster purchased at a bazaar, plugged it into his Humvee and dangled the glowing appliance from a long pole welded to the front of the vehicle.

A similar but more practical idea, also proposed by a soldier, became a countermeasure called Rhino. A glow plug -- a pencil-shaped object with an electrical heating element, often used in diesel engines -- was placed inside a metal ammunition can, which was then attached to a metal pole 10 feet in front of a Humvee or truck. The red-hot can decoyed the infrared sensor into triggering prematurely so that the copper EFP slug fired at the Rhino rather than the vehicle.

Within four to six weeks, insurgents began countering the countermeasure by aiming the EFP to fire at an angle so the slug struck 10 feet back from the Rhino. "Anything that's effective becomes ineffective," an Army colonel observed, "because this enemy will morph." The counter-countermeasure in turn provoked further measures in a variation called Rhino II, including the use of a telescoping pole that let troops vary the distance between glow plug and vehicle.

Rhino II would remain a standard feature on U.S. military vehicles in Iraq. At a cost of $1,800 each, more than 13,000 have been built, mostly at Letterkenny Army Depot in central Pennsylvania. The rectangular box on a long pole protrudes from nearly every Humvee and truck sent into harm's way in Iraq.

"Psychologically," a former Army officer said, "it's huge."

***

On the morning of Monday, Dec. 12, 2005, a tall, shambling 60-year-old man with thinning hair and the bearing of a former four-star general walked into the Pentagon basement to take command of the nation's troubled counter-IED program.

Rumsfeld and the Joint Chiefs of Staff had agreed to expand the task force: A 22-page Pentagon directive would create the Joint IED Defeat Organization, or JIEDDO, with orders to attack "the entire IED system." Votel, a capable but junior brigadier general, would soon join the 82nd Airborne Division in Afghanistan, to be replaced as director by a more senior leader with greater stature and experience.

In an emotional farewell party at the Union Street Public House in Alexandria, Votel's comrades for the past 2 1/2 years in the counter-IED struggle sent him off with sustained applause. "This was the hardest job I've ever had," he told his colleagues. "And it's the one for which I was least prepared."

His successor, Montgomery C. Meigs, seemed to have been preparing all his life for the challenge. Descended from military men, including Abraham Lincoln's quartermaster general of the same name and a father who was killed leading a tank battalion in France a month before Meigs's birth, his combat experience included the Ashau Valley in the Vietnam War and Medina Ridge in the Persian Gulf War.