The Islamic Revolutionary Guard Corps (IRGC) declared the Strait of Hormuz closed indefinitely on 12 July after its forces fired on a merchant vessel it accused of using an unauthorised route, setting off the most intense military exchange with the United States since a June ceasefire memorandum. The US Central Command (CENTCOM) responded within hours by launching a third wave of strikes in a week, hitting roughly 140 Iranian military targets including missile sites, communication networks and coastal surveillance posts. Tehran announced it had retaliated with ballistic missiles and drones against US bases and radar sites in Jordan, Kuwait, Bahrain, Qatar and Oman, while also striking a second vessel in the strait. The rapid escalation plunged the Persian Gulf into fresh crisis and directly undercut diplomatic efforts led by Oman to secure a permanent shipping regime.

Viewed from Tehran, the IRGC statement cast the closure as a necessary response to “foreign interference” and repeated US attempts to impose uncoordinated transit routes. Iranian officials insist that a June memorandum of understanding obliges Washington to end its military presence in the region and that vessels can only pass safely through Iranian-designated corridors. In parallel, Iran’s armed forces said they were targeting the sources of attacks against their territory—accusing Gulf states of hosting American bases used for strikes on Iran—though insisting civilian areas were not hit. Supreme Leader Mojtaba Khamenei, in his first public message since his father’s funeral, separately vowed revenge for the killing of his predecessor, reinforcing a political climate in which military action is presented as a national duty.

From Washington’s perspective, the US military described the latest operations as intended to “degrade Iran’s ability to attack civilian mariners and commercial ships freely transiting the strait,” after the Cyprus-flagged M/V GFS Galaxy was set ablaze and its crew abandoned ship; one crew member remained missing. Senior US officials said they had demanded Iran publicly guarantee that all lanes through Hormuz would be open without tolls, a condition they argue Tehran failed to meet. President Donald Trump declared the ceasefire over while nonetheless leaving the door open to continued talks. The Pentagon framed the strikes—over 300 targets across three nights—as a calibrated demonstration to restore deterrence, but the speed and breadth of Iran’s retaliatory attacks on American-facilitated targets across the Gulf illustrated the limits of such coercion.

The strategic waterway, through which roughly one-fifth of the world’s traded oil and liquefied natural gas normally flows, has become the central fault line in the conflict. Iran’s insistence on controlling passage and its stated intention to levy fees conflicts with the long‑standing US and Western position that Hormuz is an international strait where free navigation must be guaranteed. Oman’s mediation effort advanced a draft proposal for a dual‑corridor system—a southern lane through Omani waters with unrestricted transit, and a northern lane in Iranian waters subject to prior authorisation—but Iranian negotiators returned to Tehran without endorsing the plan, according to diplomatic sources. The collapse of that initiative, followed by the IRGC’s closure announcement and the subsequent military exchanges, leaves the interim agreement in tatters and the security of the world’s most critical energy choke point unresolved. The immediate path ahead is uncertain; Oman says talks will continue at the technical and political level, but the events of 11‑12 July have dramatically narrowed the space for compromise.