It is important to understand that the term liberal in this article is used in it's European or traditional sense. Vargas Llosa has little in common with America liberals. He is actually seen as one of the great libertarian authors of the late 20th century.
I've never read any translations of his novels, but in Spanish they are rich, tragic and funny as hell.
I suggest "Pantaleón Y Las Visitadoras" in English - "Captain Pantoja and the Special Service"