Syria's southern rebels loom large as the country's new rulers try to form an army - Syria's southern rebels loom large as the country's new rulers try to form a national army - Some fighters in Syria find new government's aim to unite rebel groups a hard sell - Clashes heat up as Syrian forces lock horns with Assad loyalists - Syria's U.S.-trained opposition fighters wait to learn of their role in a new Syria - Syrian opposition forces set sights on key town held by terrorists - Deadly fight erupts between security forces, Assad loyalists in Syria - Syrian rebels and Assad's supporters clash, leaving 2 fighters dead - Syrian police killed in violent clashes with Assad loyalists