The airstrike on the Tehran residence of Ayatollah Ali Khamenei — one of the opening salvos of the current US-Israeli war with Iran — killed the 86-year-old supreme leader together with large parts of the Iranian command structure.

Iran has yet to decide on the next leader.

Currently, however, the power vacuum appears to be filled by Iran's top national security official Ali Larijani, reportedly one of the few people trusted by Khamenei to ensure the regime's survival in case of the ayatollah's death.

Some 24 hours after the Tehran strike, Larijani took to national television and social media to decry the US and Israel for setting "the heart of the Iranian nation ablaze."

"We will burn their hearts," he said. "We will make the Zionist criminals and the shameless Americans regret their actions."

While such fiery comments are not exactly out of character for Larijani, he has also built an international reputation as a pragmatist.

During his decades-long political career, he has established himself both as a ruthless powerbroker within the regime and as a competent negotiator dealing with Russia, China, and even the US.

But with the US and Iran in open war, the 67-year-old Larijani has curtly shot down President Donald Trump's claims that Iranian leaders "want to talk" and that talks will be coming, which Trump made to The Atlantic magazine on Sunday.

"We will not negotiate with the United States," Larijani replied on X.

'Kennedys of Iran'

Larijani's new position at the top of the Iranian hierarchy is somewhat unexpected considering he has no chance of formally succeeding Ali Khamenei. Both Khamenei and his predecessor Ruhollah Khomeini were senior clerics in Shiite Islam, appointed as supreme leaders of the theocracy established following the 1979 Islamic Revolution.

The Iraqi-born Larijani is not a cleric. However, he is part of a family with deep religious and political ties within the regime, once described by Time magazine as the "Kennedys of Iran."

Larijani's father was a grand ayatollah. Ali Larijani's brother Sadeq Ardeshir Larijani has also reached the ayatollah rank while building a political career, and came to run Iran's judiciary between 2009 and 2019. Another brother, Mohammad-Javad Larijani, is a senior foreign policy figure who served as adviser to late Ayatollah Khamenei. Even before the ayatollah's death, there were rumors that the Larijani clan was trying to position one of their own as the next supreme leader.

Ali Larijani's father-in-law, late Morteza Motahhari, was also close friends with Ruhollah Khomeini and his aide during the 1979 revolution.

However, Ali Larijani officially secured his power through Iran's political system.

Born in 1958, Larijani joined the Islamic Revolutionary Guard Corps in 1981 and served as a commander during the early years of the Iran-Iraq war. He attended a religious seminary, but then obtained a degree in computer science and mathematics before moving on to secure both a master's and a doctorate in Western philosophy from the University of Tehran. Larijani's academic focus, including his 1995 PhD thesis, was on German philosopher Immanuel Kant.

Pushed out by Ahmadinejad

While pursuing his education in philosophy, Larijani also used his war background and his family connections to build a political career, eventually becoming Iran's culture minister in his mid-30s. In 1994, Ayatollah Khamenei appointed Larijani as the new head of Iran's state-funded broadcaster, where he stayed for the next decade. Larijani notably wielded the broadcaster as a pro-government propaganda tool, overseeing programs like Hoviat (Identity) which publicly branded Iran's anti-regime intellectuals as traitors funded by the West.

Larijani first ran for president in 2005, but received less than 6% of the votes in the first round and never made it to the runoff, with the election going to hardliner Mahmoud Ahmadinejad.

Instead, Larijani went on to become the secretary-general of Iran's Supreme National Security Council (SNSC) and Iran's chief nuclear negotiator. He quit the position in 2007 over apparent differences with Ahmadinejad.

Facing Tehran's partners and enemies

Clashes with Iran's extreme hardliners continued to affect Larijani's political career. Still, he managed to secure a position as parliamentary speaker in 2008 and hold it for the next 12 years. During his time in parliament, Larijani played a key role in securing legislative support for the 2015 JCPOA nuclear deal between Iran and six world powers — including the US, China, Russia, Germany, the UK, and France — which aimed to curb Iran's nuclear program in return for sanctions relief.

The deal was torn up by Trump during his first term in 2018.

In 2020, Larijani was put in charge of overseeing a strategic 25-year cooperation deal with China, which was finalized the following year.

Larijani barred from 2021 and 2024 election

Riding high on the China deal, which projected $400 billion (€345 billion) of Chinese investments into Iran's energy sector, Larijani tried to run for president again in 2021.

Unexpectedly, he was banned from running by Iran's Guardian Council. The body — which includes six Islamic clerics appointed by the Ayatollah and six lawyers approved by the Parliament — did not provide reasons for its decision. Some speculated that Larijani was excluded because his daughter reportedly lives in the US and has a British passport, while others believe this was done to clear the way for the regime's preferred candidate, Ebrahim Raisi.

Ayatollah Sadiq Larijani publicly complained that his brother had been disqualified "based on false information from the secret service" and that "falsehoods" had been deliberately spread among the Guardian Council.

The main reason for disqualifying Larijani was that he "openly criticized Raisi and members of the Revolutionary Guard" and apparently never attacked opposition figures Mehdi Karroubi and Mir Hossein Mousavi who were placed under house arrest in 2010, Iran analysist Ali Afshar told DW at the time.

Ebrahim Raisi went on to become president. However, his term was cut short after Raisi died in a helicopter crash in 2024.

Larijani then tried to run for president again, and was once again barred from the race, which was eventually won by moderate Masoud Pezeshkian.

Khamenei's man in Moscow

Last summer, Pezeshkian reappointed Larijani to his old position as head of the Supreme National Security Council, making him Iran's top security official in the wake of the 12-day war with Israel. In the months since, Larijani's authority and access to Khamenei seems to have overshadowed Pezeshkian's own.

Larijani was seen as the power behind the scenes driving the renewed nuclear talks between the US and Iran. He also repeatedly traveled to Moscow, acting like Khamenei's envoy to Vladimir Putin — presumably with the help of Iran's ambassador Kazem Jalali, who is also Larijani's close aide.

Talking to Al Jazeera just days before the US-Israeli attack, Larijani said Iran used the recent months to get "ready" for war.

"We found our weaknesses and fixed them," he said. "We are not looking for war, and we won't start the war. But if they force it on us, we will respond."

Edited by: Srinivas Mazumdaru