It's priority A1 in America's defense research labs: Coming up with technologies that can spot and defuse the roadside bombs which have proved so deadly to U.S. forces in Iraq.

But so far, Defense News reports, there hasn't been a whole lot of progress made in figuring out how to stop these improvised explosive devices, or IEDs. There's no "single silver bullet out there that can stop this threat," a member of a Pentagon task force on IEDs told the journal. "As we find some solutions that may address a particular type of weapon they’re using, a particular tactic, they shift, find new ways to do things."

Meanwhile, IEDs are doing something terrible to American troops. On Monday, an Oregon Army National Guardsman, Spc. David W. Johnson, was killed by an IED near Camp Taji, northwest of Baghdad. "Since the beginning of [Johnson's] battalion's Iraq deployment in April, eight guardsmen have been killed, all by IEDs planted on roads or in vehicles," the AP notes.

One of the only effective devices has been the Warlock Green electronic countermeasure system, which "emits a radio frequency that jams communications signals that detonate roadside bombs," according to Federal Computer Week.

"The Defense Department, however, has struggled to establish the industrial base for these systems," Defense News notes. "EDO, a New York-based firm specializing in high-tech niche products, was the only company to bid on a $35 million contract to produce 1,000 Warlock systems. And until recently, it was the only company capable of such a task — preventing mass production of the life-saving systems."

Also in the works are “change detector” sensors for unmanned aerial vehicles (UAVs). UAV program officials are seeking payloads and software that can be added to the service’s fleet of unmanned vehicles to monitor roadways and report any changes back to soldiers.

So far, the Army has tested several technologies but has not found one that works well enough to deploy, a top UAV official said this summer. Most UAV technologies can survey areas for changes, but typically are effective in dealing with objects far larger than IEDs.

THERE'S MORE: The Washington Post's Steve Fainaru was almost killed by a roadside bomb in Sadr City yesterday -- an explosion that killed four Iraqi National Guardsmen, but left their American counterparts with only sharpnel wounds.

The blast "demonstrated the uneven vulnerability of U.S. forces, who are equipped with the most sophisticated weaponry and armor, and their Iraqi allies, who fight the same battles using vastly inferior equipment," Fainaru writes in a gripping, must-read account.