The oil and gas industry has no doubt why Chinese President Hu Jintao visited Saudi Arabia last week. But his presence in four small African countries—Senegal, Mali, Mauritius, and Tanzania—was another matter.Hu’s visit to the four African countries supposedly had little, if anything, to do with his country’s interests in oil or gas or, for that matter, any commodity.“Perhaps everybody thinks that on President Hu’s visit to Africa he’ll sign this or that deal or contact about energy or mining,” Assistant Foreign Minister Zhai Jun told a news conference.“Of the five countries on the itinerary for Hu’s trip this time, apart from Sa...