(CNN)Some time in May 2014, Paul Overby, an American writer in his 70's, disappeared as he was traveling between Khost in Afghanistan and North Waziristan in Pakistan -- a region rife with the Taliban and terror groups such as al Qaeda. He has not been heard from since. On Wednesday, his wife went public for the first time with his disappearance, providing a statement to CNN and other media outlets. . . Overby's wife, who asked not to be identified by name, last heard from her husband on May 16, 2014, as he was preparing to cross the border into...