What happens if Iran's leader is removed or dies after going into hiding amid Israel and USA attacks

This is what will happen if Iran's Supreme Leader is removed from office or dies, as he has gone into hiding following attacks on the country.

Ali Khamenei has served as the second Supreme Leader of Iran since 1989 - and currently, he's in hiding for fear of assassination.

It comes as US President Donald Trump bombed three major nuclear sites in the country on Saturday night (June 21), amid rising tensions in the Middle East.

First, the US hit missiles on Fordo, a plant hidden well in a remote mountainside that is said to be crucial to Iran's nuclear ambitions, according to the BBC.

Nuclear sites at Natanz and Isfahan were also hit by the US, according to Trump. It remains unclear at this stage the exact damage caused by the US attack.

However, Trump did describe the operation as a 'spectacular military success' and stated Iran's nuclear facilities had been 'obliterated'.

Donald Trump ordered the US military to attack Iran over the weekend (Tasos Katopodis/Getty Images)

In Iran’s system, the Supreme Leader holds more power than the president, who carries out the Supreme Leader’s orders rather than setting policy independently.

Unlike presidents elsewhere, they do not have ultimate authority over the government; that power rests entirely with the Supreme Leader.

What happens when Iran’s leader dies or is deposed?

According to Iran's constitution, a group of 88 senior clerics who make up the Assembly of Experts are tasked with picking a new Supreme Leader.

This assembly is vetted by another clerical body, then approved via election, explains the Atlantic Council.

It's quite similar to the Conclave cardinals electing a new Pope in the Catholic Church.

However, these things don't often run to plan.

Over its 43-year history, Iran has changed Supreme Leaders only once, after Ayatollah Khomeini died in 1989.

Khomeini had first picked Ayatollah Montazeri to replace him, but then removed him when Montazeri publicly criticized an earlier mass execution of political prisoners. So, no new successor was named before Khomeini’s death.

Iran's Supreme Leader Ali Khamenei (Sadegh Nikgostar ATPImages/Getty Images)

When Khomeini died, the Assembly of Experts chose President Ali Khamenei, then a mid-level cleric, to take over.

Iran’s constitution was changed so that someone with a lower religious rank could be the leader, and the prime minister’s job was abolished while the presidency gained more power.

Khamenei resigned as president and was approved as Supreme Leader; Akbar Hashemi Rafsanjani then became president twice.

Over time, Khamenei, now promoted to ayatollah, outgrew Rafsanjani’s influence by building a strong alliance with the Revolutionary Guard (IRGC).

Today, the IRGC wields massive economic and security power, and likely holds more sway over choosing the next Supreme Leader than any other group.

Will Iran get a new leader according to its laws?

He has served as the second Supreme Leader of Iran since 1989 (Iranian Leader's Press Office - Handout/Anadolu Agency/Getty Images)

The New York Times has said that Khamenei has named three possible successors, which have yet to be reported.

Ray Takeyh, Hasib J. Sabbagh, Senior Fellow for Middle East Studies, Council on Foreign Relations, spoke at a media briefing on June 13.

He explained how, should foreign strikes damage Iran’s leadership but avoid mass civilian casualties, public opinion might not turn solidly against those strikes.

Why? Well, many people already distrust the government, largely due to their prioritization of building nuclear weapons.

And while a succession plan is unclear, nobody knows who would replace Khamenei, or whether that person could unite Iran’s ruling factions.

Takeyh said: "Now, the question is, can the society overwhelm the state even in its weakened condition? I don’t have the answer to that question."

In part, he continued: "They may arrive at the same conclusion as the past, that their economic vulnerabilities and other sort of ability of the Israelis and Americans to exact an economic price upon them still militates that restraint.

"But again, I don’t think they know the answer to that question. And I certainly don’t know the answer to that question, because everybody’s trying to sort this out in real time.

"Ali Khamenei is still - within the regime, at least, his ability to impose order is there. Now whether he’ll have a successor at that time with a similar degree of authority, I don’t think so, in the short term.

"Which means other centers of power will have their own prerogatives. And the regime will be much more chaotic in its decision making."