Dec. 20 issue - Predators know to hunt the weakest animal in the herd. So do the Iraqi insurgents. It is an essential truth about the Iraq war that's ingrained in soldiers like Pvt. Daniel Rocco, a Humvee gunner with the Second Battalion of the 82nd Field Artillery Regiment. Rocco's unit is an artillery regiment trained for conventional warfare, not escorting convoys. But the "Steel Dragons" of the Second now spend most of their days protecting the weak: VIP visitors and 18-wheel trucks loaded with food or other supplies on the road to Baghdad. In the process Rocco's unit gets...