Perhaps the most effective personification of public diplomacy in recent times was Vladimir Posner, a Soviet newsman who in the early 1980s appeared frequently on Ted Koppel's Nightline to defend the invasion of Afghanistan. Posner was sophisticated, dapper, and spoke perfect, idiomatic, accent-free English. It turned out that he had been born and raised in the United States. His father was a Communist who immigrated to Moscow—taking along his family, including his teenage son—after being blacklisted during the McCarthy era. In short, Posner was the perfect man for the job.
So, that's another thing Karen Hughes should be doing—looking for the Muslim equivalent of our own Vladimir Posner.
But even smart public diplomacy can only go so far. When the Afghan invasion turned disastrous, Posner could not save it—or the Soviet Union. (By the way, he managed to rehabilitate himself nicely, emerging as a pro-reform TV game-show host in the Yeltsin era.) Similarly, when the Vietnam War came to dominate nearly everything about the world's perception of America, the USIA's cleverest image-molders could do nothing to stave off the damage.
To the extent that public diplomacy has worked at all, it has done so as a garnish. The main course—a nation's ultimate image—is fashioned not by how it talks but by what it does.