The United States launched a series of strikes against Iran on Tuesday night and revoked a temporary licence that had allowed Iranian oil sales, after three commercial tankers were struck by projectiles in the Strait of Hormuz. US Central Command said the strikes were a response to Iranian attacks on the vessels, which it described as “unwarranted, dangerous, and a clear violation of the ceasefire.” The tanker incidents occurred on Monday and Tuesday: a Qatari liquefied natural gas carrier, the Al Rekayyat, caught fire after being hit; a Saudi-flagged crude tanker, the Wedyan, sustained damage; and a third vessel was struck by a drone. No crew casualties were reported, but the Qatari ship’s engine room fire raised the risk of an explosion.

Viewed from Washington, the attacks were “wholly unacceptable” and demonstrated that the memorandum of understanding (MOU) with Iran is “entirely performance-based,” according to a US official. The Treasury Department cancelled General License X, which had authorised Iranian crude and petrochemical exports until 21 August, and set a wind-down deadline of 17 July. The official added that US negotiators continue to work “in good faith towards a final deal.” From Tehran, the foreign ministry condemned both the strikes and the licence revocation as a “clear violation” of the MOU and warned of “decisive measures” to protect national security. Iranian state media implied the Al Rekayyat had ignored warnings, but the government did not formally claim responsibility. Qatar and Saudi Arabia directly blamed Iran: Doha summoned Iran’s deputy ambassador and held Tehran “fully legally responsible,” while Riyadh called the attacks an assault on international navigation and global energy supplies. Iran dismissed Qatar’s accusations as “unacceptable.”

The Strait of Hormuz, through which roughly one-fifth of global oil and gas shipments passed before the war, has become the central fault line in the US-Iran confrontation. The latest attacks prompted the US Navy-led Joint Maritime Information Center to raise the threat level for transiting vessels to “severe.” Oil prices jumped more than 5% in after-hours trading. The incidents underscore a fundamental dispute over navigation: Iran insists that all tankers use routes approved by Tehran and has warned that vessels using an alternative corridor near Oman’s coast will be targeted, while the US and its Gulf allies maintain that the strait must remain open to free international passage.

The MOU, signed in June, established a 60-day negotiating period during which Iran was to reopen the strait in exchange for limited sanctions relief, including the oil waiver. Talks were paused for the funeral of Supreme Leader Ali Khamenei, killed in the initial US-Israeli strikes in February. The next round of indirect negotiations had been expected after the mourning period, possibly on 11 July. However, the renewed hostilities cast doubt on that timeline. Iran’s foreign ministry has linked any final agreement to a cessation of Israeli operations in Lebanon, while US officials insist the MOU remains the framework for diplomacy. With both sides accusing each other of violating the ceasefire, the path to a broader settlement that would address Iran’s nuclear programme and the future administration of the strait appears increasingly uncertain.