30 Sep Washington Post - 'The single most effective weapon against our deployed forces' by Rick Atkinson.

It began with a bang and "a huge white blast," in the description of one witness who outlived that Saturday morning, March 29, 2003. At a U.S. Army checkpoint straddling Highway 9, just north of Najaf, four soldiers from the 3rd Infantry Division, part of the initial invasion of Iraq, had started to search an orange-and-white taxicab at 11:30 a.m. when more than 100 pounds of C-4 plastic explosive detonated in the trunk.

The explosion tossed the sedan 15 feet down the road, killing the soldiers, the cabdriver -- an apparent suicide bomber -- and a passerby on a bicycle. Lt. Col. Scott E. Rutter, a battalion commander who rushed to the scene from his command post half a mile away, saw in the smoking crater and broken bodies on Highway 9 "a recognition that now we were entering into an area of warfare that's going to be completely different."

Since that first fatal detonation of what is now known as an improvised explosive device, more than 81,000 IED attacks have occurred in Iraq, including 25,000 so far this year, according to U.S. military sources. The war has indeed metastasized into something "completely different," a conflict in which the roadside bomb in its many variants -- including "suicide, vehicle-borne" -- has become the signature weapon in Iraq and Afghanistan, as iconic as the machine gun in World War I or the laser-guided "smart bomb" in the Persian Gulf War of 1991...