Part one of a two-part report

Two platoons of U.S. Army scouts are in a field deep in the notorious ”Triangle of Death” south of Baghdad, a region of countless clashes between Sunni insurgents and Shia militias. The platoons are guided by a local man who’s warned them of pressure-plate improvised explosive devices, designed to explode when stepped on. He has assured them that he knows where the IEDs are, which means he’s almost certainly a former Sunni insurgent.

The platoons come under harassing fire. It stops, but later the tension mounts again as they maneuver near an abandoned house known to shelter al-Qaeda fighters. A shot rings out; the scouts take cover. They don’t realize it’s just their local guide, with an itchy trigger finger, taking a potshot at the house. The lieutenant leading the patrol summons three riflemen to cover the abandoned house.

Then all hell breaks loose. One of the riflemen, a sergeant, steps on a pressure-plate IED. The blast badly injures him, the two other riflemen, and the lieutenant. A Navy explosives specialist along on the mission immediately springs into action, using classified gear to comb the area for more bombs. Until he gives the all clear, no one can move, not even to tend the bleeding men. Meanwhile, one of the frozen-in-place scouts notices another IED right next to him and gives a shout, provoking more combing in his area. Then a big area has to be cleared so that the medevac helicopter already on the way can land. The sergeant dies several hours later in a field hospital.

That incident, which took place on 7 November 2007, exhibits many of the hallmarks of the missions in Iraq and Afghanistan—a small patrol; a local man of dubious background; Navy specialists working with soldiers on dry land; and costly technologies pressed into service against cheap and crude weapons.

And, most of all, death by IED.

”Sergeant T” became one of the 24 coalition soldiers killed by IEDs that month in Iraq. As of the end of June, IEDs have killed untold thousands of Iraqis and Afghanis, as well as 1795 coalition military people in Iraq and another 231 in Afghanistan, according to the Web site iCasualties.org. Those figures are nearly half of all combat fatalities in Iraq and roughly 30 percent of those in Afghanistan, according to the site.

IED fatalities in Iraq were down sharply in May and June, to 14 and 11, according to iCasualties. But they were up in Afghanistan, to 12 in May and 22 in June. Overall, in the first half of this year, IEDs, including suicide bombs, killed 115 coalition people in Iraq and 72 in Afghanistan. Those figures mean that in the first half of 2008, IEDs caused 54 percent of all coalition deaths (including nonhostile ones) in Iraq and 59 ­percent in Afghanistan.

The U.S. military has responded with the most intensive program of technology development in at least a decade. It has spent US $12.4 billion over the past three years on counter-IED equipment, technology R&D, training, and other measures through the Joint Improvised Explosive Device Defeat Organization and its predecessors.

JIEDDO says that its mission is to support efforts to defeat IEDs as ­”weapons of strategic influence.” This wording acknowledges that insurgent fighters use IEDs with no hope of defeating a military force in the traditional sense. The point is to cause death and destruction resulting in news imagery that affects the politi­cal will of the country that dispatched the force. This distinction is significant because it implicitly suggests that IEDs and the casualties they cause cannot be eliminated. It points to a response based on minimizing their effectiveness, for example with armor and by other means, to marginalize their strategic impact.

JIEDDO emphasizes a holistic approach, incorporating such nontechnical aspects as training troops in ­counter-IED tactics and technology and using law enforcement techniques, forensics, and intelligence to smash the networks that build and deploy IEDs. But this year, $2.57 ­billion of JIEDDO’s $4.38 ­billion budget is devoted to developing ­counter-IED technologies, feeding a perception that the agency is chasing a cure-all.

Editor’s note: To minimize the possibility that information in this article could endanger coalition personnel in Iraq or Afghanistan, a draft of this article was reviewed by current and former officials of the Joint IED Defeat Organization, a U.S. Department of Defense agency. In response to those reviews, IEEE Spectrum voluntarily removed three passages and the names of two active-duty U.S. military personnel.