The joint US–Israel strikes on Iran, which killed the Iranian supreme leader, Ayatollah Ali Khamenei, and Tehran’s retaliatory strikes on Israel and neighbouring Arab countries have again plunged the Middle East into war.
US President Donald Trump and Israeli Prime Minister Benjamin Netanyahu said their aim is to bring about a favourable regime change in Iran. The implications of this for Iran, the region and beyond should not be underestimated.
Whereas Khamenei’s killing is a significant blow to the Islamic regime, it is not insurmountable. Leaders have been killed in Iran before, including Qassem Soleimani, who was assassinated by the US in January 2020, and they have been replaced relatively smoothly.
A Regime Built for Survival
Khamenei’s departure is unlikely to mean the complete of the Islamic regime in the short run. He reportedly arranged a line of succession for his leadership and that of senior leaders last week, anticipating the possibility of being “martyred”.
However, Khamenei was both a political and spiritual leader, commanding followers across Iran and the wider Muslim region. His assassination could spur some to seek revenge, potentially sparking extremist violence.
Under the Islamic Republic’s constitution, the Assembly of Experts will now appoint an interim or long-term leader. There are three likely candidates: Gholam-Hossein Mohseni-Eje’i, the head of the judiciary; Ali Asghar Hejazi, Khamenei’s chief-of-staff; and Hassan Khomeini, the grandson of Ayatollah Rohullah Khomeini.
The regime is well-equipped to ensure its survival, with the Islamic Revolutionary Guard Corps (IRGC) and the Basij group prepared to suppress domestic uprisings and defend the regime. Their loyalty is tied to the regime, as is that of administrators and bureaucrats, motivated by Shi’ism and nationalism.
Trump and Netanyahu have called on the Iranian people to topple the regime, but so far, the state apparatus appears to be firmly backing the government.
Global Economic Pain
Iran has already retaliated against Israel and US military bases in the Persian Gulf, using ballistic missiles and drones, causing some damage. The IRGC has also moved to choke the Strait of Hormuz, a vital waterway for global oil and gas supplies, through which 20% of the world’s oil and 25% of its liquefied gas flows daily.
The United States has vowed to keep the strait open, but the IRGC is well-placed to disrupt traffic. This could have serious implications for the global economy.
Both sides have crossed previous red lines, and open warfare is now engulfing the region. China and Russia have condemned the US-Israeli actions, and the United Nations has called for de-escalation, but the chances of a return to negotiations appear slim.

Frequently Asked Questions
What is the aim of the US and Israel’s strikes?
US President Donald Trump and Israeli Prime Minister Benjamin Netanyahu said their aim is to bring about a favourable regime change in Iran.
Has Iran retaliated?
Yes, Iran has already hit back at Israel and US military bases across the Persian Gulf, using short-range and long-range advanced ballistic missiles and drones, causing some damage.
What is the significance of the Strait of Hormuz?
The Strait of Hormuz is a narrow waterway through which 20% of the world’s oil and 25% of its liquefied gas flows daily. The IRGC has moved to choke the strait, which could have serious implications for the global economy.
What will the long-term consequences of this conflict be for the region and the world?
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