At a time when Iran’s clerical establishment is confronting perhaps the most consequential crisis in its history, two very different leadership transitions illuminate competing visions of the country’s future.

On Sept. 6, the National Council of Resistance of Iran, the principal organized opposition to the ruling theocracy, elected Mahnaz Maimanat, 67, as its new secretary-general as the organization entered its 62nd year. The election followed three rounds of voting involving members in seven countries.