Since the death of Osama bin Laden, Yemen has become the hottest front in the war against Al Qaeda. Now, with headlines about a terrorist plot to bomb a U.S.-bound airliner, award-winning reporter Ghaith Abdul-Ahad travels deep into Yemen’s radical heartland. In this first-hand report, FRONTLINE looks at how members of Al Qaeda in the Arabian Peninsula (AQAP) and affiliated militants have seized control of areas in southern Yemen and are winning some popular support. Is the United States’ expand...