The Spymaster Speaks - While the possibility of a nuclear-armed Iran becomes an election year issue, the former head of Israel's intelligence service, Meir Dagan, sits down with Lesley Stahl to discuss the Iranian nuclear question. Teacher to the World - On his educational website, "Khan Academy," he teaches millions of students across the world each month. Sal Khan's teaching method has become so effective that it may be the future of American education. Aerosmith - An inside look at how, despite their differences, one of America's premier rock bands defied age, substance abuse and changing musical tastes to stay together for 40 years. Lara Logan goes on tour with and interviews the members of Aerosmith.