Iran orders ships into Tehran-approved Hormuz lanes

Hormuz is conditionally open: ships can move, but Iran wants them to move on its terms. In late June, Iran's Revolutionary Guards told shipowners that only Tehran-designated routes through the strait are permitted, warning of a "severe response" against vessels that refuse (CNBC). The strait carries roughly 20 million barrels of crude per day and about a fifth of global LNG trade (EIA). For Europe, the test is practical: if insurers and shipowners obey Tehran's route before governments act, Iran gains control without a formal closure.

Two Lanes, One Threat

After the US and Iran agreed an interim reopening framework on June 17, Oman offered a toll-free corridor along its coast, coordinated with the IMO (the UN's shipping-safety body) (Gulf Industry/ONA). Ships tested it. On June 24, 78 vessels crossed the strait, 42% taking the Omani route (S&P Global). The next day, the IRGC rejected any non-Iranian lane.

That rejection created the core problem. Under UNCLOS (the UN law of the sea), no coastal state can suspend "transit passage" through straits used for international navigation (UNCLOS). Iran's claim goes further: Tehran asserts the right to decide which route counts, and to threaten ships that choose otherwise.

Who Actually Decides a Voyage

Governments declare principles. Captains decide voyages. A ship approaching Hormuz today checks war-risk insurance, P&I club guidance (the mutual insurers that cover liability for shipping accidents), sanctions counsel, and charterparty clauses before checking the weather. P&I clubs have said cover is unavailable for sanction-breaching trade (Shipowners' Club). BIMCO's standard war-risk clauses let owners refuse any transit they judge unsafe (BIMCO). Insurers say they may need months of stability before premiums come down (CNBC).

The result is a double bind. Using Tehran's approved lane risks sanctions exposure. Avoiding it risks physical danger and unaffordable insurance. Iran does not need to blockade the strait if private gatekeepers shut the alternatives.

What Europe Can and Cannot Do

The EU has acted, but with tools designed for a different kind of pressure. On June 8, the Council (where member-state governments make joint decisions) imposed sanctions against an IRGC Navy unit and two individuals under a newly extended framework, the first time the EU used sanctions specifically to defend freedom of navigation (2eu.brussels, Firstpost). France insists on unconditional free navigation and frames any military response as demining and escort (La Gazette France).

Sanctions freeze assets and restrict travel. They do not clear mines or make an unsafe lane commercially viable. Europe's two naval missions in the area show the gap. EMASOH/Agenor, a French-led European surveillance operation with about eight member states contributing, monitors the strait but carries no enforcement mandate (EMASOH). Operation ASPIDES, launched in 2024 to protect Red Sea shipping, can escort ships through danger zones but was built to deter Houthi attacks, not to compel a coastal state to accept alternative corridors (Council of the EU).

Europe's energy link to Hormuz runs through prices, not pipelines. Most of the strait's crude flows to Asia, so disruption hits Europe as higher global oil and freight costs rather than missing tankers. The European Commission has flagged aviation fuel as one sector where the squeeze could bite hardest (EIA, Infobae/EFE).

The 60-day US sanctions license underpinning the current truce expires on August 21. If ships keep using Oman's corridor and underwriters start quoting workable prices for it, Iran's grip loosens. If mines and attacks leave only the Iranian route safe enough to insure, transit passage — the legal rule that no coastal state can block an international strait — starts to depend on the threat actor's permission. That precedent reaches well beyond the Gulf.