A few months ago, a friend and I spent a week in Cuba—not the usual Canadian stay in a beachside resort, but a week spent tramping the streets of Havana seeking out baseball games, opera, and the wonderful music that is the island nation's rightful trademark. We enjoyed the music and the weather, but the overwhelming impression was depressing: grinding poverty, decayed buildings, and the leaden air of a police state. Last week, Yoani Sánchez, a 34-year-old Cuban writer, editor, and linguistics scholar, won the Columbia University's Maria Moors Cabot Prize for journalism that advances inter-American understanding. Cuban authorities...