Oil surged after the US struck Iran’s three main nuclear sites and threatened further attacks, exacerbating a crisis in the Middle East and stoking concerns that energy supplies from the region could be disrupted.Global benchmark Brent rallied as much as 5.7% to $81.40 a barrel, before paring some of that gain in heavy trading. Timespreads widened. US President Donald Trump said air attacks had “obliterated” the trio of targets, and threatened more military action if Iran didn’t make peace. In its initial reply, Tehran warned the strikes would trigger “everlasting consequences.”Brent’s prompt spread — the difference between its two nearest contracts, and a closely followed metric — widened to as much as $1.99 a barrel in backwardation, from $1.53 on Friday. That’s a bullish pattern indicating concern about tight prompt supplies.The US assault — which targeted sites at Fordow, Natanz, and Isfahan — dramatically raises the stakes in the confrontation and increases the premium that traders are pricing into the global energy market. Still, the extent of the gains will depend on how Tehran opts to respond to the US moves.The oil market has been gripped by the crisis since Israel attacked Iran more than a week ago, with futures pushing higher, options volumes spiking along with freight rates, and the futures curve shifting to reflect tensions about tighter near-term supplies. The Middle East accounts for about a third of global crude output, and a sustained increase in prices would boost inflationary pressures worldwide.“The market will closely watch Iran’s response — particularly whether it will move to disrupt Middle Eastern oil flows, directly or indirectly through its regional proxies,” said Muyu Xu, a senior crude analyst at Kpler Ltd. “If Iran blocks the Strait of Hormuz, even for one day, oil can temporarily hit $120 or even $150.”There are multiple, overlapping risks for physical crude flows. The biggest centers on the Strait of Hormuz, should Tehran seek to retaliate by attempting to close the chokepoint. About a fifth of the world’s crude output passes through the waterway at the entrance to the Persian Gulf.Iran’s parliament has called for the closure of the strait, according to state-run TV. Such a move, however, could not proceed without the explicit approval of Supreme Leader Ayatollah Ali Khamenei.Rival SuppliersIn addition, Tehran could opt to target crude infrastructure in rival suppliers in the Middle East, such as fellow OPEC+ producers Saudi Arabia, Iraq or the United Arab Emirates. Both Riyadh and Baghdad expressed concern following the US attack.Elsewhere, Iran could orchestrate attacks on ships on the other side of the Arabian peninsula in the Red Sea, encouraging Yemen-based Houthi rebels to harass vessels. After the US attacks, the group threatened retaliation.If the hostilities escalate, Tehran’s own oil-producing capabilities could be targeted, including the key export hub at Kharg Island. Such a move, however, could send crude prices soaring, an outcome that Washington might want to avoid. So far, Kharg Island has been spared, with satellite imagery pointing to a drive by Iran to expedite its exports of oil.The crisis will also throw a spotlight onto the Organization of the Petroleum Exporting Countries, and its allies including Russia. In recent months, OPEC+ has been relaxing supply curbs at a rapid clip seeking to regain market share, and yet members still have substantial idled capacity that could be reactivated.Among the wider market fallout, fuels also strengthened on Monday. Diesel futures gained as much as 7.8% to hit the highest price since July 2024, outpacing the move in crude.Prices:Brent for August settlement was 2.1% higher at $78.64 a barrel at 6:53 a.m. in Singapore.More than 200,000 lots of Brent futures traded across the curve in the first half an hour of the session, a larger-than-usual volume.The intraday peak of $81.40 a barrel was the highest price since mid-January.West Texas Intermediate for August delivery gained as much as 6.2% to $78.40 a barrel, and traded at $75.47.. Read more on Markets by NDTV Profit.