Iran Forces Ships Into Hormuz Lanes

Hormuz has not been shut. That is the point. Ships are still moving through the strait, but Iran is trying to make them move by its rules. In late June, Iran's Revolutionary Guards told shipowners that only Tehran-designated routes through the waterway were permitted, warning of a "severe response" against vessels that refused (CNBC).

That matters because Hormuz is one of the narrow places where the global economy becomes very physical. Roughly 20 million barrels of crude a day pass through it, along with about a fifth of global LNG trade (EIA). For Europe, and for Ireland through fuel and freight prices rather than direct supply lines, the immediate question is practical. If insurers and shipowners begin following Tehran's preferred route before governments can hold the line, Iran gets a measure of control without ever declaring the strait closed.

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 body responsible for shipping safety (Gulf Industry/ONA). Ships began to test it. On June 24, 78 vessels crossed the strait, with 42% taking the Omani route (S&P Global). The following day, the IRGC rejected any lane not approved by Iran.

That is where the legal and commercial problems meet. Under UNCLOS, the UN law of the sea, coastal states cannot suspend "transit passage" through straits used for international navigation (UNCLOS). Iran is going further than a safety warning. It is claiming the power to decide which route counts, and threatening ships that choose another.

Who Actually Decides a Voyage

Governments can make statements about freedom of navigation. Captains and shipowners still have to decide whether a voyage can be made. A vessel approaching Hormuz now checks war-risk insurance, P&I club guidance, sanctions advice and charterparty clauses before it worries about the weather. P&I clubs, the mutual insurers that cover liability for shipping accidents, have said cover is not available for trade that breaches sanctions (Shipowners' Club). BIMCO's standard war-risk clauses allow owners to refuse any transit they consider unsafe (BIMCO). Insurers say it may take months of stability before premiums fall (CNBC).

That leaves shipowners in a trap. Use Tehran's approved lane and they risk sanctions exposure. Avoid it and they may face physical danger, or premiums so high that the voyage no longer makes commercial sense. Iran does not need a formal blockade if the private gatekeepers of global shipping make the alternatives unusable.

What Europe Can and Cannot Do

The EU has moved, but its tools were built for a different kind of pressure. On June 8, the Council, where member-state governments take joint decisions, imposed sanctions against an IRGC Navy unit and two individuals under a newly extended framework. It was the first time the EU used sanctions specifically to defend freedom of navigation (2eu.brussels, Firstpost). France has insisted on unconditional free navigation, presenting any military response in terms of demining and escort missions (La Gazette France).

Sanctions freeze assets and restrict travel. They do not clear mines, lower insurance costs or make a contested lane commercially viable. Europe's two naval missions in the region show the limit. EMASOH/Agenor, a French-led European surveillance operation with about eight member states contributing, monitors the strait but has no enforcement mandate (EMASOH). Operation ASPIDES, launched in 2024 to protect Red Sea shipping, can escort vessels through dangerous waters, but it was designed to deter Houthi attacks, not force a coastal state to accept alternative corridors (Council of the EU).

Europe's exposure to Hormuz runs mainly through prices, not pipelines. Most crude passing through the strait goes to Asia, so the European hit comes through higher global oil prices, dearer freight and pressure on sectors that live close to fuel costs. The European Commission has already pointed to aviation fuel as one area where the squeeze could be felt most sharply (EIA, Infobae/EFE).

The 60-day US sanctions licence holding up the current truce expires on August 21. If ships continue to use Oman's corridor and underwriters begin quoting workable prices for it, Iran's leverage weakens. If mines and attacks leave only the Iranian route insurable, transit passage, the rule that no coastal state can block an international strait, starts to depend on the permission of the actor threatening it. That precedent would travel far beyond the Gulf.