Although no one in the United States could have realized it at the time, the Soviet invasion of Afghanistan in late 1979 was a seminal moment in the life of a young, devout Sunni Muslim whose father was a billionaire construction magnate in Saudi Arabia. Osama bin Laden, then 22, was "deeply upset" when he heard an "infidel" army attacked Afghanistan, an event that would turn out to be "the most transformative of his life, launching him into a full-time job helping the Afghan resistance," writes Peter Bergen in his new biography, The Rise and Fall of Osama bin Laden. And few in the West noticed when bin Laden, a decade and a half later, issued his first public declaration of war against the United States, a vow of holy war repeated in 1997 during a television interview produced by this episode's guest. The journalist and al-Qaeda expert Peter Bergen discusses the purpose of his short, comprehensive biography of al-Qaeda's dead leader: to explain why and how bin Laden chose to dedicate his life to mass murder. Among the subjects covered in this episode: Islam at the heart of al-Qaeda; bin Laden's battlefield exploits in Afghanistan; the myth of CIA-bin Laden cooperation; why so few people in the West noticed him prior to 1998; and his escape from Tora Bora in late 2001.