Iran's Islamic Revolutionary Guard Corps has stepped up enforcement operations in the Strait of Hormuz, turning back at least eight vessels around July 4 with direct warnings. This marks a hardening of control that coincides with the state funeral of Supreme Leader Ali Khamenei and reveals a widening gap between Tehran's written commitments and its actual conduct on the water.

On June 17, Iran and the US signed a memorandum of understanding in which Tehran agreed to use its best efforts to restore shipping traffic to pre-blockade levels and to hold off on imposing tolls for 60 days. Yet the MOU, as The Guardian noted, functions as "a loose guideline of objectives as opposed to a rigid set of enforceable rules" — a characterization the data now bears out. On July 2, Marine Traffic recorded 38 confirmed crossings, a 10% day-on-day decline. Iranian-flagged vessels surged to 11 crossings that day, up from two the previous day, while nine additional crossings breached sanctions restrictions. Traffic began shifting away from the southern corridor — which runs closer to Oman and had become the preferred bypass route — toward Iranian-controlled passages and unidentified shipping lanes.

A Narrowing Corridor

The strait's geography shapes the crisis. The northern route, which Iran controls, is less trafficked but more heavily mined. The southern route, hugging Oman's coast, had become the default passage for vessels stuck waiting for clearance. Its viability depends on mine-clearing operations and diplomatic flexibility, both of which are now under pressure.

French President Emmanuel Macron announced around July 2 that France and the UK would deploy mine-clearing ships to open the southern passage. Tehran's foreign ministry rejected the plan as "unwarranted and unjustified interference." The Institute for the Study of War assessed on July 2 that Iran has signalled it intends to use force to push vessels onto Iranian-controlled routes exclusively. Reuters reported on July 1 that senior Iranian officials confirmed Tehran intends to maintain sovereign control over the strait.

Iran's posture did not begin this week. On June 20, the navy declared the strait "completely closed," warning all vessels their safety could be compromised without authorization, according to Iran International. Renewed warnings on June 25 caused additional vessels to turn back, per Al Jazeera and gCaptain. A tanker struck by an unidentified projectile on June 27 sustained bridge damage; the crew was reported safe by UKMTO and Anadolu Agency. On July 5, UKMTO also reported a vessel in the Red Sea that sent a distress signal after an attack by unknown armed assailants near Hodeidah, Yemen — evidence that the security threat extends beyond the strait itself. President Trump has separately asserted that Iran fired at least four one-way attack drones at transiting ships, causing damage, per Crisis Group.

The deeper institutional question is this: who governs the strait, under what legal authority, and at what cost? Oman has been quietly positioning itself as a mediating power. It held trilateral talks with Iran, France, and the UK on future governance and proposed a framework modeled on the Strait of Malacca — a system of optional navigational fees covering safety, docking, route guidance, and environmental protection. The International Maritime Organization has reportedly endorsed the Omani approach.

Iran's response has been competitive rather than collaborative. The Guardian noted in late June that Tehran was "jealously competing with Oman as decision-maker over the strait." In June, Iran announced its own plan to introduce maritime fees once a 60-day negotiation window ends — the same window the MOU is designed to govern. The IMO briefly suspended its own ship-escort operation around June 25 after a reported incident, illustrating how gaps in enforcement ripple through multilateral operations.

Oil prices have moved in the opposite direction from Tehran's leverage. Crude has dropped from a peak of $125 per barrel to around $75, a 40% decline that reflects expanded global supply. This price shift reduces, though does not eliminate, the economic pressure a prolonged Hormuz blockade could otherwise exert on consuming nations.

The broader context matters here. Trump has stated that US-Iran talks will not resume until Khamenei's funeral concludes — a six-day event drawing millions, internally significant because Supreme Leader Khamenei's son Mojtaba was notably absent from the July 5 ceremony, leaving succession questions unresolved. Calls for Trump's death were reported at the funeral, setting a tense tone for any future negotiations.

The 60-day toll freeze in the MOU expires in mid-August. What happens between now and then — the IRGC's operational decisions, the pace of French-British mine clearance, whether Oman's governance proposal gains traction, and the resolution of Iran's succession uncertainty — will determine whether the strait returns to normal commercial passage or whether the current restrictions harden into a new normal.