Who – or what – will replace Iran’s supreme leader Ali Khamenei

Leadership transitions in dictatorships can signal upheaval – for better or worse – and in Iran that moment has now arrived. The death of the supreme leader, Ali Khamenei, in a US airstrike on Tehran on February 28 marks the most consequential rupture in the Islamic Republic’s political system since 1989.

Unlike the managed transition that followed the death of Ayatollah Ruhollah Khomeini (who led the country from the 1979 revolution for ten years, after which Khamenei took over) things are different. This succession will take place amid acute domestic unrest, economic crisis and unprecedented external military pressure. What follows now will have far-reaching consequences.

In the end it was an act of war rather than revolution or old age that ended Khamenei’s rule. But it had been clear for some time that, like other ageing dictators, he could not continue indefinitely. Until recently, the question of succession focused on the likelihood of preferred individuals rising to take his place, including Khamenei’s son Mojtaba or the now-deceased former president, Ebrahim Raisi.

However, the huge protests in January, which drew suggestions from Trump that he would be open to regime change, prompted Khamenei to choose Ali Larijani, a former Islamic Revolutionary Guard Corps (IRGC) general and secretary of the Supreme National Security Council, to effectively run the country. The extraordinary capture by US forces of the Venezuelan president, Nicolás Maduro, just a few weeks earlier no doubt also weighed heavily on the Ayatollah’s mind.

Iran’s military weakness and vulnerability to external pressure are clearly crucial factors. The prospect of ongoing US or Israeli intervention in Iran – and their ability to target individuals in the regime at will – remains decisive. But it is also now essential to consider how domestic factors such as factionalism or a struggle between rivals could emerge in a more unstable succession scenario.

Given the extent of the regime’s decapitation in the air strikes of February 28, where some 50 top officials were targeted, it is unclear whether Larijani can maintain the status quo. But the entire Iranian elite will now surely operate under the assumption that their own safety cannot be assured. Nevertheless some senior politicians with governing experience have thus far survived. These include former president Hassan Rouhani, the speaker of Iran’s parliament, Mohammad-Bagher Ghalibaf, and of course Larijani himself.

Potential succession scenarios

It is impossible to predict the future of any autocratic regime, especially one that has lasted for decades in the face of almost constant pressure. But four kinds of outcomes now appear plausible based on internal dynamics alone.

First, a “digging in” scenario, in which a senior cleric is approved by Iran’s Assembly of Experts who then seeks to maintain the existing system with minimal changes or concessions. This would not involve any real change to the status quo, at least for the immediate short term. This is the outcome that Khamenei sought. Despite the risk of further targeted strikes, the regime is now attempting to put this kind of organised clerical succession in place.

If this is achieved, it is less likely that the Assembly of Experts would concede to demands for fundamental political change and, therefore, further violence and repression of future protest could follow.

Second, a “cut and run’ scenario” in which key leaders decide in due course that their days are numbered and, like Bashar al Assad in Syria, flee the country. If at first this scenario sounds appealing to those who want to see the end of the Islamic Republic, it should be tempered by the very real problem of a power vacuum emerging, leading to institutional chaos and state collapse. Even in 1979, when the late shah, Mohammad Reza Pahlavi, went into exile, there were a multiplicity of potential power brokers waiting in the wings to replace him. Today no such factions exist. There is no guarantee that Iran would become more liberal or open as a result, even with further external pressure.

Third, a “suppression and succession” scenario, in which the regime becomes more reliant on the Islamic Revolutionary Guard Corps to brutally reassert its authority. This would raise the prospect of a quasi-military junta emerging with weaker clerical legitimacy. Such an evolution could produce a more threatening regime that both stifles dissent and doubles down on resisting US and Israeli pressure.

Fourth is the possibility of a popular uprising actually succeeding. But it remains unclear – given our limited understanding of the situation on the ground – who the Iranian population would support and whether they could succeed without one of Iran’s military institutions taking their side. Iranians would have to take to the streets and face the remnants of a tyrannical regime willing to fight to remain in power. This could result in a highly unpredictable situation. But if Iran’s dominant institutions are further degraded by consistent US military pressure, this scenario also becomes more likely.

Whatever form succession takes in Iran, the regional consequences will be significant. Israel will have contingency plans and further military options ready, while Gulf Arab states are likely to try and deescalate tensions as fast as possible. Despite their obvious anger at Iran’s attacks on their own territory, the key for the Gulf Cooperation Council will be to quickly establish workable ties with whatever regime emerges in the long term and enforce some form of cold peace, while minimising the disruption inside their own countries.

Turkey and Pakistan both have have serious security concerns, particularly if Kurdish and Baloch militants inside Iran try to establish a political foothold as the country begins to fragment. Meanwhile Russia and China, though wary of losing a partner and facing energy disruption, have limited ability to shape outcomes despite both seeing Iran as a strategic partner.

For Europe, the moment carries both danger and opportunity. Calibrated sanctions relief could reduce escalation, deter civil war and prevent Tehran’s deeper alignment with Moscow and Beijing. However, Europe’s leverage will largely depend on whether Trump wishes to see through a policy of regime change or not. There are difficult choices ahead, but deescalation with whatever kind of government in Iran emerges should surely be the priority.

The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.