Can Iran close the Strait of Hormuz?

Iran holds the north shore of the strait and maintains IRGC naval bases along that coastline. It also controls three islands inside the strait: Abu Musa and the Greater and Lesser Tunbs, seized in 1971 and still disputed with the UAE. From those positions, Iran can deploy Noor anti-ship cruise missiles, sea mines, and swarms of fast-attack craft (the IRGC’s favoured asymmetric tactic). Tehran has threatened closure many times since the 1980s Tanker War. Each time, the threat was credible enough to move oil markets.

What actually happened: on 28 February 2026, US-Israeli airstrikes (Operation Epic Fury) triggered the IRGC to close the strait to commercial shipping. A formal closure declaration followed in early March 2026. This was the first sustained closure in the strait’s modern history as a major oil corridor. Hundreds of vessels were stranded within weeks, and roughly 410 vessels remain holding position away from berth on either side today, while the world’s major carriers either suspended Hormuz transits or rerouted south of the Cape of Good Hope.

The self-deterrent has always been that Iran exports its own oil through the strait, primarily to China. A prolonged closure costs Iran export revenue and political goodwill with its primary customer. That economic brake does limit the duration a closure can be maintained without severe self-harm. In the 2026 case, however, the IRGC overrode that constraint in response to direct strikes on Iranian territory, demonstrating that military confrontation removes the self-deterrent.

Under international law, the Strait of Hormuz is an international strait governed by UNCLOS Part III. Transit passage rights apply: all vessels, civilian and military, have the right to unimpeded transit. A unilateral closure is contrary to international law. Iran disputes elements of this framework, arguing that its own territorial-sea laws take precedence. The counter-position, held by the United States and most of the international community, is that transit passage cannot be suspended unilaterally. The US Navy is the only force capable of enforcing that position at scale.

A reopening framework was signed but did not hold. The Islamabad Memorandum, signed 17 June 2026, was meant to reopen the strait toll-free for 60 days, yet the ceasefire frayed within days: Iran re-declared the strait closed, the US and Iran traded fresh strikes, and passage is cut off again. In early July Iran attacked commercial ships in the strait, the United States answered with a bombing campaign and reimposed sanctions and its naval blockade, and President Trump declared the ceasefire over on July 8. Iran has retaliated against US bases in Jordan, Qatar, Bahrain and Kuwait and re-declared the strait closed until further notice, while an Oman-mediated corridor through Omani waters stays contested. In late July the war widened to a second chokepoint when Yemen's Houthis attacked two Saudi tankers in the Red Sea. A three-night pause in the strikes broke on July 28, when Iran's Revolutionary Guard fired ballistic missiles at US forces in Jordan, all intercepted per US Central Command; the United States answered with strikes on militia sites in Iraq and then a heavy overnight wave on Iran itself, which Iranian state media say killed a family of three on Qeshm Island. On July 30 a drone hit two LNG vessels at Egypt's Damietta port, the first time the war has touched Egypt; no one has claimed it and Iran denies involvement. Saudi Arabia announced a 14-country Maritime Defense Alliance for shipping routes. Oman is mediating, but Iran rejected its plan to manage the strait jointly under voluntary fees. Traffic has begun to return: a Qatari LNG tanker made the first such transit in nearly three weeks and analysts put throughput at roughly a third of pre-war levels, with Brent near $90. On August 1 two tankers were hit off Oman near the strait within hours of each other, one of them carrying natural gas, and Kuwait intercepted Iranian drones aimed at a US base. Tehran still calls the strait closed and says US pressure will tighten it; the US military publicly rejects that, saying ships are still transiting. Roughly 6,000 seafarers remain stranded in the Gulf. Only a handful of ships transited, and a durable reopening now depends first on the hostilities stopping for good. The live status is at Is the Strait of Hormuz open?, the reopening timeline at When will the strait reopen?, and the full diplomatic record at Peace talks timeline.