The conflict triggered by US and Israeli strikes against Iran and its repercussions in the Middle East are expected to send oil prices soaring when the market opens on Sunday night and could shake the global economy if it continues.

The oil market opens at 23:00 GMT on Sunday and analysts expect a sharp rise in prices.

"I expect oil prices to trade between $85 and $90 on Monday," said Amena Bakr, OPEC+ and Middle East specialist at Kpler.

This would represent a significant jump in the price of Brent crude, the international benchmark for oil, which had nevertheless gradually incorporated a geopolitical risk premium to reach over $72 on Friday. A far cry from the $61 at the beginning of the year.

With the regional conflagration, maritime transport via the Strait of Hormuz, through which some 20% of the world's oil consumption passes, is compromised.

The strait is not completely closed (a few Chinese and Iranian ships have reportedly passed through, according to Kpler), but it's almost as if it were. Insurance costs are becoming prohibitive in this context, explains Ms. Bakr, and the major shipping companies have already confirmed they are suspending their fleets from transiting this waterway.

- Trump's "Achilles' heel" -

"Alternative infrastructure in the Middle East can be used to bypass the flows through the strait, but the net impact remains an effective loss of 8 to 10 million barrels of crude oil supply," said Jorge Leon, an analyst at Rystad Energy, in a note the day before.

In theory, oil-importing countries have reserves, with OECD members required to maintain 90 days of oil stocks, but prices above $100 are not ruled out.

If the blockade of the Strait of Hormuz continues, "no matter how much oil is in the strategic reserves", the loss of export volumes through this crucial passage "is simply too significant", Ms. Bakr emphasizes.

"Trump's Achilles' heel is high oil prices," says Michelle Brouhard, also an analyst at Kpler.

According to her, Iran is therefore seeking to keep crude oil prices high in order to force Donald Trump to back down after he promised his electorate low prices, while the United States is already preparing for the midterm election campaign at the end of the year.

"Detrimental impact on growth"

Gas prices are also expected to surge on Monday, as Qatar is a key exporter of liquefied natural gas, increasing inflationary risks.

Indeed, rising hydrocarbon prices are bad news for the economy. The last time crude oil prices exceeded $100 was at the beginning of the war in Ukraine. Gas prices also skyrocketed, which largely contributed to a prolonged cycle of rising prices.

Increased prices at the pump, energy prices, maritime transport costs, loss of revenue for air transport, the conflict "can have a detrimental impact on growth", Eric Dor, professor at IESEG School of Management, told AFP.

"If it's for 3 days, it's not a big deal, but if it's for a longer period, then yes, it will be an additional recessive effect," he summarizes.

On the stock market, some sectors could be winners on Monday, such as the defense sector, but the economist expects rather "declines" in prices, particularly in "the air transport sector, the maritime transport sector probably, and tourism".