Shipowners will not resume transit through the Strait of Hormuz for at least several weeks until they see concrete proof that a US-Iran agreement has translated into safe passage, the head of one of the world’s largest shipping groups has warned. Jotaro Tamura, chief executive of Japan’s Mitsui O.S.K. Lines, told the Financial Times that operators would remain cautious despite any political declaration. “What will have to come in place is not just a simple agreement between the relevant countries, but it has to be material and translated into the real situations in the Strait of Hormuz, so that shipping lines can make themselves comfortable to go through,” he said. His remarks, echoed by industry analysts in London and Singapore, underscore a deep scepticism that the vital waterway can be reopened quickly, even after Washington claimed progress.

Viewed from Washington, President Donald Trump declared on Truth Social that the strait would be “completely open” by Friday and that ships were already moving through a “totally safe” southern route. Yet that assertion clashes with the reality on the ground. The Iran war that began on 28 February with US-Israeli strikes largely halted commercial traffic through the chokepoint, which normally carries about a fifth of the world’s oil and liquefied natural gas, along with significant volumes of aluminium and urea. Dozens of vessels remain trapped or have been rerouted, and shipping insurers are refusing to provide cover without verifiable security guarantees.

From Tokyo to London, maritime executives and security analysts agree that a return to normal transit patterns will be slow and painstaking. The CEO of Mitsui O.S.K. suggested the process could take “at least a couple of weeks, if not a month.” Beyond the political deal, practical obstacles loom: suspected minefields must be cleared, international transit lanes re-established, and port operations on both sides of the Gulf restored. Iranian threats to disrupt the strait in the past, combined with the recent conflict, have left a legacy of mistrust that no ceasefire announcement can instantly erase.

Viewed from Tehran, the calculus is equally complex. While a deal may offer economic relief, Iran’s history of asymmetric retaliation in the Gulf means that even a formal agreement will be scrutinised for loopholes. Shipping insurers, many of them based in London, are likely to maintain war-risk premiums until they see sustained, incident-free transits. Energy markets, meanwhile, are already pricing in a prolonged disruption: crude and LNG futures have not retreated to pre-war levels, reflecting the view that the strait’s reopening will be gradual and conditional.

Forward-looking analysis suggests that the Hormuz bottleneck will remain a source of volatility for weeks. Even if a political framework is announced, the shipping industry’s demand for “material” proof of safety—backed by mine-clearance operations, naval escorts, and a track record of unimpeded passage—will delay any large-scale return of tankers. For Asian economies heavily dependent on Gulf hydrocarbons, the wait will be particularly costly, forcing continued reliance on longer, more expensive alternative routes. The strait’s full reopening, analysts in London and Tokyo concur, hinges less on declarations than on the slow, unglamorous work of restoring trust on the water.