Cuban Communist Party official Caridad Diego comes to the U.S. regularly to shop and visit relatives. When she returns to Cuba, she resumes her 9-to-5 job as director of Havana’s Office of Religious Affairs. The title sounds bland, but Ms. Diego oversees the repression of independent Cuban religious leaders. Like many bureaucrats in corrupt regimes, Ms. Diego arbitrarily enforces the law against her political enemies while flouting the same rules as she pleases.