The Wall Street Journal announced today that reporter Gina Chon, who was revealed by recently leaked emails to have slept with a National Security Council Iraq expert while covering that country, has resigned.

"You can't fuck the elephants while you're covering the circus" is an old journalistic maxim—often attributed to the Washington Post's Ben Bradlee the New York Times' Abe Rosenthal—delineating the boundaries of appropriate reporter-source relationships. Sleep with whomever you want, in other words, with the exception…