Early this year, a 10-year-old Afghan named Esrarullah got his first chance in months to see his father, who had been held since last May at Bagram Air Base outside Kabul. It was not in person, but in a video conference call, and the boy was so overcome, he clutched the phone to his ear and stared mutely at the screen. Afghan families like his are traveling from distant provinces and turning up by the hundreds for a similar chance to get a glimpse of loved ones who have been held at the American base for months, sometimes years, without charges or legal redress.