THE LATEST CONCERNS at the Guantanamo Bay prison camp is a sharp reminder that America can’t take security for granted–even at its most remote outposts. The capture of Ahmed Fathy Mehalba is even more unsettling because it involved a former Army soldier and naturalized U.S. citizen (by way of Egypt) who was employed as a civilian contractor by the military. The war on terror has presented the Pentagon with a dilemma: In order to fight an enemy, you have to first understand them–literally. With few Arabic speakers in its ranks, the Pentagon has resorted to contracting American citizens to act as translators. While the incident with Mehalba exposes the risks of hiring translators for sensitive intelligence work, others who operate in far more risky and austere environments have displayed a courage and patriotism seldom matched.