HOUSTON — When President Biden meets Crown Prince Mohammed bin Salman in Saudi Arabia, he will be following in the footsteps of presidents like Jimmy Carter, who flew to Tehran in 1977 to exchange toasts with the shah of Iran on New Year’s Eve.
Like the prince, the shah was an unelected monarch with a tarnished human rights record. But Mr. Carter was obliged to celebrate with him for a cause that was of great concern to people back home:…