In early September, Iran's Supreme Leader Ayatollah Ali Khamenei made a surprise announcement that he was having surgery and asked people to pray for his health. Rumors about Khamenei have circulated for years. But there has never been such a media blitz on the health of the Supreme Leader, who holds substantial influence or constitutional authority over the executive, legislative and judicial branches of government as well as the military and media.
The head of the surgical team said Khamenei had an operation on his prostate which lasted less than half an hour and only local anesthetic had been used. He was completely awake and speaking during the procedure, the surgeon said. But if Khamenei's health deteriorates, the traditional clergy and the Islamic Revolutionary Guard Corps - Iran's top military force and an economic powerhouse - will need to settle on a successor quickly if the country is to avoid a period of political instability, experts say.
So far, Iran has had only two Supreme Leaders since the 1979 revolution, with Khamenei succeeding the Islamic Republic's founder Ayatollah Ruhollah Khomeini in 1989. Supreme Leaders are elected by the Assembly of Experts, which is made up mostly of the clerical old guard. But it is clear that the Revolutionary Guards will also play a major role.
Whoever replaces Khamenei is unlikely to wield as much power in the same position. "The clergy are looking for somebody to guarantee the interests of the clergy. The Revolutionary Guards are looking for someone to guarantee the interests of the Revolutionary Guards," said Mehdi Khalaji, a former senior fellow at the Washington Institute for Near East Policy who is now the CEO of the Idea Center for Arts and Culture.
"Neither of them wants somebody who can come in and control them."
Disputed presidential elections in 2009 led to mass street protests followed by a wave of arrests, including of two candidates who remain detained at their homes.
Given this, the complicated process of choosing a new leader and the transition of power that follows could also provoke unrest. "If this uneasy equilibrium is suddenly changed, you will have unintended uprisings or unintended consequences," said Abbas Milani, the director of the Iranian Studies program at Stanford University.