Crude prices rose sharply on Monday after Iran declared it had again closed the Strait of Hormuz, accusing Israel and the United States of violating an interim peace agreement. Brent futures touched $82.30 early in the session before settling at $81.11, while West Texas Intermediate jumped 2.6 percent to $78.62. The move reversed part of last week’s over 8 percent slump, which had been driven by hopes of a sustained ceasefire and the release of stranded Gulf tankers.

Tehran blamed Israeli strikes that killed at least 20 people in Lebanon a day after a ceasefire with Hezbollah took effect, describing them as a clear breach of commitments. Washington disputed the closure, noting that 55 vessels carrying 17 million barrels sailed through the strait over the weekend, though several supertankers switched off tracking systems after crossing. The White House threatened military action if a deal fails and floated the idea of charging tolls for transit rights.

Talks between US Vice President JD Vance and Iranian officials in Switzerland started acrimoniously, with the Iranian delegation walking out in protest at Trump’s warning of renewed bombing. Diplomats later resumed intensive discussions covering the nuclear programme, the strait’s status, and conflict-prevention mechanisms. Viewed from European capitals, the fragile truce looks increasingly threadbare, even as negotiators push for a 60-day halt to hostilities.

Analysts caution that a genuine reopening of Hormuz would require coordinated vessel movements, infrastructure repairs and demining—a process that could take weeks. Saudi Aramco has warned that prolonged disruptions risk delaying market stability until 2027, while Morgan Stanley sees a “race against time” before global stockpiles become critically low. The next milestone is whether the Swiss talks can yield a credible mechanism to keep the strait open and end the Lebanon violence, or whether Iran continues to use the waterway as a bargaining chip.