DUBAI, United Arab Emirates—A recording of Iran’s foreign minister offering a blunt appraisal of diplomacy and the limits of power within the Islamic Republic has been leaked, providing a rare look inside the country’s theocracy. The release of the comments by Mohammad Javad Zarif set off a firestorm within Iran, where officials carefully mind their words amid a cut-throat political environment that includes the powerful paramilitary Revolutionary Guard, ultimately overseen by the country’s supreme leader. Zarif has been suggested as a possible candidate for Iran’s June 18 presidential election as well. Outside of Iran, Zarif’s comments could also affect talks in Vienna aimed at keeping the 2015 nuclear deal with Iran together. Already, sabotage targeted Iran’s nuclear facility at Natanz during the talks as Tehran has begun enriching a small amount of uranium up to 60 percent purity, which edges the country closer to weapons-grade levels. After the leak became …