On December 27, 2007, a suicide bomber killed Benazir Bhutto, the former prime minister of Pakistan. Brilliant and charismatic, the head of a political family as important to Pakistani history as the Gandhis in India or the Kennedys in the United States, Bhutto had recently returned from exile to challenge military dictator Pervez Musharraf in a democratic election. In the aftermath of the assassination, some blamed Musharraf; others blamed terrorists...