"The military junta that ruled Argentina from 1976 until the restoration of democracy in 1983 preferred not to jail "subversives" but to exterminate them, maintain the authors. Hence the infamous "disappearances," a subterfuge in which Gen. Jorge Videla's security forces seized, tortured and apparently murdered thousands. Simpson and Bennett covered the regime's end and the commencement of Raul Alfonsin's presidency for BBC television. They offer...