From London: As Australians woke on Sunday morning, the Islamic Republic of Iran was attempting something it has only done once before in its 47-year history: replacing a supreme leader. The killing of Ayatollah Ali Khamenei in joint US-Israeli strikes on Tehran on Saturday has set in motion a succession process that is, even in peacetime, byzantine in its complexity. In wartime, with bombs still falling and senior commanders dead, it borders on the chaotic.
Khamenei had ruled Iran for nearly 37 years, succeeding the republic's founding father, Ayatollah Ruhollah Khomeini, in 1989. He died without an officially declared heir, as reported by 9News, leaving a constitutional mechanism that was designed for an orderly transition now having to function under sustained military pressure. US Central Command confirmed it had struck more than 1,000 targets in Iran across two days of operations, including ships, submarines, missile sites, communications links and the command-and-control centres of the Islamic Revolutionary Guard Corps (IRGC).
Who Holds Power Now?
Under Article 111 of Iran's constitution, when the incumbent supreme leader dies, the Assembly of Experts must appoint a successor as soon as possible. In the interim, a Provisional Leadership Council — comprising the president, the chief justice and a cleric from the Guardian Council selected by the Expediency Council — carries out the supreme leader's duties. That council was formally stood up on Sunday. It includes the moderate president, Masoud Pezeshkian, the hard-line head of the judiciary, Gholamhossein Mohseni Ejei, and a senior cleric, Alireza Arafi.
The council faces an immediate dilemma over who controls Iran's military response. The temporary council must decide whether to continue delegating defence decision-making to Ali Larijani, Iran's top national security official, and parliament speaker Mohammad Bagher Ghalibaf — both men who led Iran's defence during the 12-day war with Israel in June, alongside Ali Shamkhani, a former navy rear admiral who was killed in Saturday's strikes. Israel has claimed that a majority of Iran's senior military leaders, including the armed forces chief of staff and the IRGC commander, were killed in the initial wave of attacks, according to 9News.
The Succession Process
According to Article 111 of the Iranian constitution, the Assembly of Experts is charged with supervising, dismissing and electing the supreme leader. The Assembly consists of 88 Mujtahids elected from lists of thoroughly vetted candidates by direct public vote for eight-year terms. The body's composition, however, heavily favours hardliners: the Guardian Council is known for disqualifying candidates, including former President Hassan Rouhani, a relative moderate whose administration struck the 2015 nuclear deal with world powers, who was barred from election for the Assembly in March 2024.
Sanam Vakil, director of the Middle East and North Africa programme at the Chatham House think tank, told CNN that the Assembly may not convene until US and Israeli operations wind down. "They cannot risk further death and damage to the institution," she said. The contrast with 1989 is stark: when Khomeini died, Khamenei was named his successor within a day, making a transition council unnecessary. This time, there is no comparable speed or clarity on offer.
The Candidates
No single figure commands consensus. Analysts say there is currently no single dominant figure widely viewed as capable of matching Khamenei's combined political authority and religious standing. Three names recur in expert analysis. Alireza Arafi, a Shiite cleric named to the transition council, was appointed to several senior positions by Khamenei and is seen as a strong contender. He is deputy chairman of the Assembly of Experts and a member of the Guardian Council, meaning he could in effect vet his own candidacy. He is also head of Iran's seminary system.
One of Khamenei's sons, Mojtaba, a 56-year-old Shiite cleric, has been mentioned as a potential candidate, though he has never held government office. A father-to-son transfer could spark anger not only among Iranians already critical of clerical rule, but also among supporters of the system. Some may see it as un-Islamic and akin to creating a new religious dynasty, recalling the 1979 collapse of the US-backed Shah's government. Mohammad Mehdi Mirbagheri, representing the most conservative wing of the clerical establishment and sitting in the Assembly of Experts, is another contender, as is Hassan Khomeini, a grandson of the republic's founder who is known to be less hardline than his peers.
The IRGC's Shadow
Behind every public contender lies a less visible power: the IRGC. Although many of its senior leaders are thought to have been killed in this weekend's strikes, the force remains formidable. Economic conglomerates connected to the IRGC are estimated to control up to 60 per cent of Iran's economy, securing the organisation's financial independence and leverage over state institutions. While the Assembly of Experts holds the formal constitutional mandate to select the supreme leader, the IRGC's praetorian function positions it as a de facto arbiter, capable of endorsing or obstructing candidates through its command of the security apparatus.
Vakil of Chatham House told CNN that "moments of succession tend to strengthen conservative and security-driven factions, at least initially" and that "any internal debate about the country's direction is likely happening quietly and within narrow elite circles rather than in public view. If reform politicians have ambitions, this is their now-or-never moment."
The Regime-Change Question
President Donald Trump has urged Iranians to overthrow their government, telling them it would "probably" be their "only chance for generations," according to 9News. Yet even some of the operation's strongest advocates acknowledge the limits of that aspiration. Retired US Army General David Petraeus, a former CIA director, told CNN that unlike the Syrian case in 2024, there is no organised opposition force ready to assume power. As news of Khamenei's death broke, Iranians poured into streets in some cities in expressions of celebration, though security forces were deployed and an internet blackout was imposed to prevent a broader uprising.
Reza Pahlavi, the eldest son of the deposed shah, has attracted Western commentary as a potential figurehead, though he has lived in the United States since the 1979 revolution and leads no organised political or military structure inside Iran.
What It Means for Australia
For Canberra, this crisis is not abstract. Iran directed at least two attacks on Australian soil in 2024, targeting the Jewish community in acts intended to "create fear, divide our society and challenge our sovereignty." In response, Australia expelled Iran's ambassador, suspended operations at its embassy in Tehran, and listed the IRGC as a state sponsor of terrorism. The government has sanctioned more than 200 Iranian-linked individuals, including more than 100 linked to the IRGC.
Prime Minister Anthony Albanese, Defence Minister Richard Marles and Foreign Minister Penny Wong said in a joint statement that Australia "stands with the brave people of Iran," declaring support for the US's actions to prevent Iran from obtaining a nuclear weapon. The government's Smartraveller portal was updated to its highest alert level, issuing "Do Not Travel" advice for Iran and Iraq, and "Reconsider Your Need to Travel" for the wider Gulf region, including the UAE, Qatar and Jordan.
Australia's alignment with the operation reflects both genuine national-security logic and the obligations of its AUKUS partnership. Iran-linked cells have operated on Australian soil; the IRGC is now a listed terrorist organisation under Australian law. China's Foreign Minister Wang Yi condemned the US-Israeli action as "unacceptable" and argued the strikes "violate international law and the basic norms of international relations," calling for the immediate cessation of military action. The EU's foreign policy chief, Kaja Kallas, described Khamenei's death as "a defining moment in Iran's history," adding that "what comes next is uncertain" but that "there is now an open path to a different Iran, one that its people may have greater freedom to shape."
That tension — between the strategic logic of degrading a regime that has repeatedly threatened Western allies, and the profound uncertainty of what comes next — sits at the heart of this crisis. Whoever emerges from the succession process will inherit a country under military attack, an economy buckled by sanctions, and a population whose reaction to their leader's death has been, in at least some cities, one of relief. Whether that creates space for something better, or simply a more desperate version of the same regime, is the question that will define the next chapter of Middle Eastern history. Reasonable people, including inside the alliance that launched these strikes, are far from agreed on the answer.