CAMP FOSTER, Okinawa — When Rodrico Harp was sentenced to seven years at hard labor for his part in the infamous abduction and rape of an Okinawa schoolgirl in 1995, he never thought he’d be assembling cell phones or making auto parts. That’s what he claims “hard labor” meant at Kurihama, the Japanese prison near Yokosuka where most American servicemen convicted in Japanese courts wind up. “I made parts for Mazdas and Nissans,” Harp said during a telephone interview from his home in Griffin, Ga. “You had no choice. If you refused to work, they put you in what we...