Ben Johnston recoiled in horror when he heard one of his fellow helicopter mechanics at a U.S. Army base near Tuzla, Bosnia, brag one day in early 2000: "My girl's not a day over 12."

The man who uttered the statement -- a man in his 60s, by Johnston's estimate -- was not talking fondly about his granddaughter or daughter or another relative. He was bragging about the preteen he had purchased from a local brothel. Johnston, who'd gone to work as a civilian contractor mechanic for DynCorp Inc. after a six-year stint in the Army, had worked on helicopters for years, and he'd heard a lot of hangar talk. But never anything like this.

More and more often in those months, the talk among his co-workers had turned to boasts about owning prostitutes -- how young they were, how good they were in bed, how much they cost. And it wasn't just boasting: Johnston often saw co-workers out on the streets of Dubrave, the closest town to the base, with the young female consorts that inspired their braggadocio. They'd bring them to company functions, and on one occasion, Johnston says, over to his house for dinner. Occasionally he'd see the young girls riding bikes and playing with other children, with their "owners" standing by, watching.