When the Libyan dictator Muammar Gaddafi was killed during the 2011 revolution, it seemed like good news for democracy in the Muslim world. But in 2012, the American ambassador and three other Americans were killed in a bloody attack in Benghazi, and today, a split between government factions has ceded large portions of the country to ISIS fighters and other extremists. Simon Ostrovsky reports from the front lines, where rival militias fight to save Libya as we know it.