The land mine that took Joao Silva's feet worked perfectly.

Silva, a brilliant and courageous photojournalist on contract to the New York Times -- and, in the eyes of many colleagues, one of the finest combat photographers of his generation -- suffered grievous injuries Saturday after stepping on a mine while embedded with U.S. troops in southern Afghanistan. Three nearby American soldiers suffered concussions from the blast. This suggests that the device was a miniature antipersonnel mine -- the difficult-to-detect plastic type that are usually no larger than a cosmetics jar, or a can of tuna. Silva didn't die because he wasn't supposed to. The weapon's maker -- given its location, probably an old Soviet arms manufacturer -- had calculated the exact formula of explosives and shrapnel required to maim, shredding tissue and smashing bones, but not to kill. Thus, its agonized victim must be carried off the battlefield by comrades, tying down even more manpower. Force multiplication, the military calls it.