by Anne Applebaum, Slate Magazine, USA - With an unerring sense of timing, President Robert Mugabe of Zimbabwe arrived in Rome this weekend, thereby demonstrating the profound limitations of international diplomacy. Indeed, it's hard to think of any other single gesture that would so effectively reveal the ineffectiveness of international institutions in the conduct of both human rights and food-aid policy. Even someone standing atop the dome of St. Peter's, megaphone in hand, shouting, "The U.N. is useless! The EU is useless!" couldn't have clarified the matter more plainly.