ISIS presents itself as the holiest citadel of warriors, as a group serving God’s pure and ordained will on Earth. But when the leader of ISIS’s most hated adversary mocks its deceased caliph (emperor) as a fool who ran into a dead-end tunnel while being chased by lowly dogs, it erodes ISIS’s credibility. It underscores how the organization, which at one point nearly qualified for its own seat at the United Nations, is now perceived as a sad joke.