Iran enters a new era on Monday, with the appointment of Mojtaba Khamenei as supreme leader to succeed his father, on the tenth day of a war that plunges markets into panic and sends oil prices soaring.

The Islamic Republic, attacked by the United States and Israel ten days ago, continues its strikes against the infrastructure of its Gulf neighbors, which are rich in hydrocarbons and host American military bases.

An Iranian strike caused a fire early in the day at the Al-Maameer oil refinery complex in Bahrain, according to state media.

Between the blockade of the Strait of Hormuz, through which a fifth of the world's oil and liquefied natural gas (LNG) production passes, damage to energy infrastructure and fears about the stability of the region, the markets are panicking.

European stock markets opened sharply lower, with Paris falling 2.59%, Frankfurt 2.47% and London 1.57% in early trading.

In Asia, the Tokyo Stock Exchange closed with a plunge of around 5% while Seoul plummeted by 6%.

The price of a barrel of oil briefly exceeded $118, its highest level since the summer of 2022, following Russia's invasion of Ukraine. European gas prices jumped by about 30%.

Since the start of the war on February 28, the barrel of West Texas Intermediate (WTI), the reference of the American market, has recorded a rise of 70%, unprecedented over such a short period.

Faced with this shock to the global economy, the G7 finance ministers are meeting by videoconference on Monday at 12:30 GMT. The use of strategic oil reserves is an "option under consideration" that is expected to be discussed, according to a source within the French government.

Donald Trump, for his part, believes that the initial objective of the war—to deprive Iran of any capacity to produce nuclear weapons—is worth these sacrifices. It's a "very small price to pay for the peace and security of the United States and the world," the American president asserted on his Truth Social network.

Washington indicated on Sunday that it would provide military protection to ship owners seeking to move their tankers out of the Gulf. Meanwhile, traffic remains virtually paralyzed in the strait – with media outlets reporting only the passage of a few ships identifying themselves as Chinese.

Without hesitation, "one minute"

The Islamic Republic, which Israel and the United States portray as being on its knees, has appointed a new supreme leader in continuity.

Mojtaba Khamenei, a 56-year-old religious figure considered close to Iranian conservatives due in particular to his links with the Revolutionary Guards, the ideological army of the Islamic Republic, has managed to overcome the reluctance of the regime's most reformist members.

He succeeded his father Ali Khamenei ten days after his death in the American-Israeli offensive.

In Tehran, the Assembly of Experts asserted that it "did not hesitate for a minute" in entrusting him with the reins of the country. The Revolutionary Guards, the armed forces, the police, and the diplomatic corps immediately pledged their allegiance to him.

In response, the Houthi rebels in Yemen, allies of Tehran, hailed it as "a major blow to the enemies of the Islamic Republic".

On Monday, three pro-Tehran Iraqi armed factions did the same, convinced that Khamenei Jr. would follow "the blessed continuation of the Islamic Revolution".

In Iran, official media showed scenes of jubilation across the country, with Iranians waving Islamic Republic flags or the lights of their mobile phones in the night.

His entry into office will nevertheless be extremely restricted. Israel had already announced on Wednesday that the new supreme leader would be "a target".

As for Donald Trump, who claims a right to scrutinize Iranian power, he warned on Sunday that the new supreme leader "would not last long" without his approval, even before the choice of Mojtaba Khamenei's name was officially announced.

He had also already stated last week that he would not accept the son of the supreme leader taking over.

Beijing rejects all interference

Beijing, on the other hand, soberly described the decision as "in accordance" with the Iranian Constitution, saying it opposed any foreign action that would target the new leader.

The Israeli army announced a new wave of strikes targeting missile launch sites, Revolutionary Guard and police command centers, and a rocket engine factory.

An Iranian drone injured 32 civilians, four of them seriously, in Sitra, Bahrain, according to the Ministry of Health. Saudi Arabia announced the interception of four drones heading towards the Shaybah oil field in the southeast of the country, which was already attacked on Sunday.

Neither side is showing any willingness to de-escalate the situation. In an interview Sunday with The Times of Israel, Donald Trump asserted that a cessation of hostilities would be a "mutual" decision with Israeli Prime Minister Benjamin Netanyahu.

Meanwhile, Israel is also targeting Iranian oil infrastructure, in order to further weaken its enemy's already depleted economy.

His army announced it had struck several fuel depots in Tehran. Thick black smoke from the oil tanks plunged the Iranian capital into an apocalyptic darkness on Sunday, accompanied by the smell of burning.

"The air has become unbreathable," testified a resident reached by telephone from Paris. "We don't want them to bomb our national resources and make us even poorer than we already are."

There was no indication on Monday that this mutual destruction of infrastructure would stop quickly. "If you can tolerate oil at over $200 a barrel, continue with this game," the Iranian army threatened.

Israel also announced on Monday that it had resumed its strikes on pro-Iranian "Hezbollah infrastructure" in Beirut.

Overnight, fierce fighting broke out between the Shiite movement and Israeli helicopters in eastern Lebanon, near the Syrian border.