After the disputed re-election of the Iranian president Mahmoud Ahmadinejad in June 2009, the clerical regime in Tehran consolidated its grip on power and stifled internal challenges. To the outside world, it appeared that Iran was torn by a conflict between Shiite Islam and democracy.
But last year's unrest and violent crackdown in Iran were actually battles in a larger war that has been raging for centuries within Shiism - a struggle over who should rule the faithful, and how.
Shiite clerics have long debated their role in politics. The "quietist" school - rooted in the sect's tradition of seeking to avoid confrontation with powerful rulers - argues against direct engagement in political matters. The more activist school emphasises the martyrdom of one of Shiism's founding figures, Imam Hussein, who advocated rebellion and confrontation. But even within the activist school, there is a debate over the extent of clerical power.
The model of absolute rule that dominates Iran today is just one of several competing doctrines within the Shiite clergy. Wilayat al Faqih, or "guardianship of the jurist", triumphed under Ayatollah Ruhollah Khomeini, the leader of Iran's 1979 Islamic Revolution. Khomeini's charisma and political skill overshadowed the more moderate vision of Shiism emanating from the Iraqi city of Najaf. By eclipsing the Najaf school, Khomeini succeeded in combining the role of Shiite theologian with that of political leader.
Any long-term change in Iran could be driven by a return to a more traditional interpretation of this concept - one that emphasises rule by consensus, as opposed to an all-powerful leader.