Negotiators from Iran and the P5+1 powers led by the U.S. are racing against a March 31 deadline to conclude a nuclear deal in Lausanne, Switzerland. Secretary of State John Kerry told reporters on Saturday that negotiators had made “genuine progress” but that “important gaps remain.”

Yet what happens if the Iranian leadership that the U.S. and others are dealing with now is not in place to implement any agreement? Two recent developments suggest that the Islamic Republic may be heading toward one of its cyclical spasms of...