(CBS News) Secretary of Defense Leon Panetta said recently that al Qaeda terrorists may regroup in Africa, and that is why the U.S. is sending 100 Special Forces troops to one of the most violent places on Earth. The first 40 Americans have arrived in the region that includes South Sudan, scene of a long running civil war, and the Congo, site of the deadliest conflict since World War II. CBS Evening News anchor Scott Pelley sat down with Panetta, who said the Americans will train local forces to fight terrorists, including al Qaeda. Pelley: You're sending a hundred troops...