Iran Reimposes Strait of Hormuz Restrictions Amid U.S. Naval Blockade Tensions

Iran reimposed tight restrictions on vessel traffic through the Strait of Hormuz on Saturday, just a day after declaring the vital oil chokepoint “completely open” during a 10‑day ceasefire between Israel and Hezbollah. The reversal came as the U.S. naval blockade on Iranian shipping remained in force, sending fresh shockwaves through already strained global energy and shipping markets ketv +1.

The Iranian military’s joint command said “control of the Strait of Hormuz has returned to its previous state … under strict management and control of the armed forces,” effectively requiring ships to seek Iranian authorization to cross the narrow waterway, which normally carries around a fifth of global oil and liquefied natural gas trade ketv +1. Britain’s maritime security agency reported that two Islamic Revolutionary Guard Corps (IRGC) gunboats opened fire on a tanker attempting to transit the strait; the vessel and crew were later reported safe kptv.

How the Reversal Collides With the U.S. Blockade and Oil Markets

Tehran’s move followed a brief window on Friday when Foreign Minister Abbas Araghchi said the strait was open to “all commercial vessels” for the duration of the Lebanon ceasefire, triggering a sharp sell‑off in energy markets as traders bet on a rapid restoration of Gulf exports nypost +1. Brent crude futures fell about $9.01, or just over 9%, to $90.38 a barrel, while U.S. WTI dropped $10.48, roughly 11.5%, to $83.85 — the steepest one‑day falls in weeks nypost.

But even as Iran proclaimed the waterway open, President Donald Trump insisted that “the naval blockade will remain in full force and effect as it pertains to Iran, only, until such time as our transaction with Iran is 100% complete” jpost. U.S. Central Command later said American forces had already turned back 21 ships linked to Iran since the blockade began on Monday, underscoring that any reopening would be partial and contested at best ketv. Analysts warned that with “more than 10 million barrels per day” of oil and about 20% of global LNG flows disrupted during the earlier closure, each policy swing now feeds directly into a volatile risk premium on crude nypost.

Ships Test the Strait as Industry Demands Safety Guarantees

Despite the uncertainty, vessel‑tracking data on Saturday showed a convoy of eight tankers — including a very large crude carrier and several LPG and product carriers — moving through the Strait as owners sought to exploit what they hoped would be a short window of safer passage kptv. Other ships that attempted to exit on Friday ultimately turned back amid confusion over designated safe corridors and the risk of sea mines highlighted in advisories from navies and insurers jpost.

Major shipping lines and industry bodies, including Maersk, Hapag‑Lloyd and the Norway Shipowners’ Association, said they would not resume normal traffic without clear assurances on mine clearance, internationally recognized transit lanes and legal protections for freedom of navigation jpost. The International Maritime Organization said it was verifying whether any Iranian “managed passage” regime complied with global rules, while European leaders discussed potential demining and escort missions jpost. “If this represents a step towards an opening, it is a welcome development,” Norway’s shipowners chief Knut Arild Hareide said of Friday’s announcement — remarks overtaken within 24 hours by Iran’s renewed restrictions jpost.

The Bigger Picture

The on‑off nature of Hormuz access has turned the strait into the central pressure point of the 2026 Iran war, with Tehran leveraging control over a global energy artery and Washington wielding a blockade aimed at Iran’s own exports. With gunfire already reported against a tanker and both sides hardening their positions, energy and shipping experts warn that markets remain one miscalculation away from a deeper supply shock — and, potentially, a broader regional escalation ketv +2.