One man's campaign to build schools in the most dangerous, remote, and anti-American reaches of Asia: in 1993 Greg Mortenson was an American mountain-climbing bum wandering emaciated and lost through Pakistan's Karakoram. After he was taken in and nursed back to health by the people of a Pakistani village, he promised to return one day and build them a school. From that rash, earnest promise grew one of the most incredible humanitarian campaigns of...