Reopening Hormuz is no longer the only question — the terms of passage matter too

The closer a Hormuz agreement appears, the more the goalposts move. Iran and Oman appear to be edging toward an agreement on navigation rules, but Tehran is tying any reopening to a broader bargain with Washington covering sanctions relief, access to frozen assets, and an end to military threats — even as US rhetoric hardens. Diplomatic optimism lifts markets, only for fresh demands and tougher rhetoric to pull them back.

That stop-start diplomacy points to a bigger problem: Reopening Hormuz was never going to be one decision. Even a signed lane agreement would only settle where ships can sail, not whether they will — shipowners and ins’ers still get the final word on whether the result is safe, sanctions-compliant, and insurable. So the more important questions are no longer simply when Hormuz reopens, but under what terms, who sets the rules, and how markets price the new reality.

Iran doesn’t need to close Hormuz to control it

The emerging system won’t look like a conventional blockade. It’s more likely to divide vessels by route, ownership, and political affiliation, giving Iran leverage through selective permission rather than a physical barrier.

Two operationally distinct routes have already emerged, Marisks CEO Dimitris Maniatis tells EnterpriseAM. A northern route through Iranian-controlled waters carries the lowest immediate physical threat for ships Tehran accepts, but owners risk sanctions and interdiction if passage requires coordinating with — or paying — a sanctioned Iranian entity. A southern route through Omani waters offers communication support via the Naval Cooperation and Guidance for Shipping mechanism and US naval forces, short of an escort or security assurance, Maniatis says.

The result is already a divided transit environment: Vessels tied to governments Iran considers friendly get favorable treatment, like China, while western-linked tonnage is effectively excluded, Maniatis says. Flag is only one part of the calculation, with beneficial ownership, technical management, charter arrangements, cargo interests, and prior port calls factoring in.

“Iran is presently holding the contest over commercial decision-making,” Maniatis tells us. Tehran doesn’t need complete physical control if every owner must calculate which authority to coordinate with, whether its ins. holds, and how much political exposure they can tolerate.

That calculation is the shift itself, Knightsbridge Strategic Group partner Finley Grimble tells EnterpriseAM. Hormuz gives Iran influence over global energy flows disproportionate to its conventional military strength, and Tehran is unlikely to accept an arrangement that strips away its ability to shape maritime security — though it could trade informal coercive power for political recognition, economic normalization, and a formal place in Gulf security, if it believes the arrangement will endure. “The central trade-off is between informal coercive leverage and formal institutional influence,” Grimble says.

The possible outcomes

The endgame falls into four broad categories — a multilateral institution, an informal Iran-Oman compromise, de facto Iranian control, or continued managed instability — plus a fifth, longer-term one Grimble adds: the Gulf gradually reducing Hormuz’s importance through pipelines, alternative ports, and new logistics corridors without resolving the governance dispute.

Over the next year or two, Grimble’s war-gaming puts managed instability at the highest odds (35%), followed by infrastructure-led redundancy (25%), de facto Iranian dominance (20%), informal Iran-Oman accommodation (15%), and a multilateral institution (5%) — though the latest talks complicate that taxonomy, since several scenarios could coexist. Iran and Oman could agree on lanes without a broader US-Iran settlement, and an “on paper” bilateral system could still leave Tehran exercising effective control through vessel approvals and selective enforcement.

A multilateral institution is the cleanest route to predictable governance — and the least politically attainable, Grimble says. Iran would join if it strengthened Tehran’s legitimacy; Saudi Arabia and the UAE would resist anything giving Iran effective veto power over Gulf security; Oman has the clearest incentive, since it reinforces Muscat’s role as trusted intermediary; and Washington would back a mechanism that protects navigation and eases its military burden, but not one that restricts its operational flexibility. The problem isn’t a lack of common interest — every major actor benefits from stable shipping. The problem is that each fears the arrangement could institutionalize somebody else’s strategic advantage.

Enforcement is the likely failure point, Grimble says. Payment and lane management are technically solvable, but disagreements over attribution and proportional response could turn one incident, a vessel refusing routing instructions, a disputed payment, a deniable attack, into a geopolitical crisis. “The key variable is rarely the incident itself, but whether established communication channels, agreed procedures, and political trust are sufficient to prevent misperception from becoming strategic escalation,” he says.

The market can insure a transit. It cannot make owners sail

War-risk cover on a Hormuz transit recently ran 7.5-10% of a vessel’s value, reaching 15% in at least one case, Lloyd’s List Intelligence Finance Editor David Osler tells EnterpriseAM. A supertanker worth USD 130-140 mn would face a bill of USD 10-14 mn, or over USD 20 mn at the high end. There’s no consensus price — underwriters compete, and large owners with desirable fleets get better terms — just a going rate that moves with ins’ers’ perception of threat, reacting to political developments within 24 hours, Osler says. Ins’ers have no privileged intelligence on US, Iranian, or Israeli decision-making; they watch the same headlines as everyone else and reprice accordingly.

The larger problem is that insurability does not equal willingness to sail. Almost any voyage can be covered at the right price, Osler says, but most owners won’t accept the physical danger even when cover is available. The minority who will sail, for the right contract, are now fueling disputes between owners and charterers — charterers citing successful voyages as proof contracts remain performable, owners invoking force majeure to refuse passage. Ins. no longer just adds cost to a voyage; in some cases, it decides whether the voyage is legally possible at all.

A fee regime would add another complication. The Lloyd’s Market Association has advised ins’ers not to cover shipowners against future Hormuz transit fees imposed by any party, Osler says, reflecting regulatory concerns about charging vessels for international passage. Iran could frame the payment as an environmental levy or navigational charge rather than a toll, with vessels registering ownership, flag, cargo, and transit plans, Maniatis says. Tehran already has the surveillance, patrol craft, and boarding teams to enforce it selectively. The bigger hurdle is creating a recognized payment system that doesn’t breach sanctions or void ins. — making financial acceptance more important than the fee itself.

A February cliff edge

One risk has received relatively little attention. Owners of ships trapped in the Gulf could become entitled to total-loss payouts after 12 months of “deprivation of use” — a threshold that starts arriving in February 2027. The resulting bill could reach USD 20 bn, Osler says, likely the biggest crisis at Lloyd’s since the asbestos claims of the 1990s nearly sank the market. The market is still months from that point, and a settlement could avert it, but pricing pressure will build if ships remain trapped. The International Maritime Organization said in July that hundreds of vessels and around 6k seafarers were stranded in the Gulf after renewed attacks halted evacuation efforts.

What returns first?

Even after an agreement, Hormuz won’t snap to normal. Crude and refined products would likely return first because they move in large volumes, have strong commercial incentives, and, in many cases, fewer practical alternatives, Ziya Mammadov, transport and logistics executive at Azerbaijan Railways, tells EnterpriseAM. Container shipping would return more cautiously, waiting for successful transits, workable ins., and evidence the security arrangement holds before restoring schedules.

Risk-tolerant shipowners and state-linked fleets could test the route first, CSC Commodities Energy Analyst Sasha Foss tells EnterpriseAM. A rush of pent-up oil could follow, but Asian buyers are unlikely to abandon the diversifications built during the shutdown — Japan and South Korea have leaned on the US as a structural supplier, Foss says, and while Gulf barrels would remain attractive because of their proximity, supply security is now permanently higher on buyers’ agendas.

Safe transits will matter more than the nominal duration of any initial agreement. Successful voyages could lower perceived risk faster than a political promise, while one attack could reverse that immediately. Markets have already shown that distinction as prices fell sharply on optimism that Iran and Oman were approaching an agreement, before Tehran’s broader demands from Washington tempered expectations. The market priced the possibility of an agreement; it hasn’t priced confidence in its implementation.

“Some [bypass] detours will end, others will become permanent,” former head of supply chain and transport industries at the World Economic Forum Wolfgang Lehmacher tells EnterpriseAM. Diverting a voyage is reversible; redesigning networks, signing new inland contracts, and promising customers multi-route resilience are not, and companies that have built backup corridors won't abandon them for marginal savings.

What businesses should watch

A signed Iran-Oman agreement would be the start of the test, not the end. Watch which vessels get approved to transit, whether treatment differs by ownership, how the first voyages are insured, and whether the US tolerates coordination with Iranian authorities — plus whether any payment mechanism clears legitimately, whether mines come out of the recognized lanes, how fast charter disputes resolve, and whether safe passage accumulates without attacks or sudden changes to routing instructions.

The most stable outcome is not necessarily a return to a formally open passage. It may be a system carrying a permanent but predictable premium, since owners can price clear rules more easily than nominal freedom backed by coercive uncertainty. The agreement that matters won't be the one that reopens the strait. It will be the one that makes passage predictable enough for an owner to sail, an ins’er to cover the voyage, and a producer to trust the route again. But even that wouldn’t unwind the deeper shift we’ve tracked since the war’s early days: redundancy and optionality are now the name of the game, and the logistics industry is treating backup routes — imperfect as they are — as capacity worth paying for. Hormuz may regain its flow.

“Diversification remains the only free lunch,” Foss says. The supply chain model has shifted from just-in-time toward just-in-case.