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 370 vessels remain anchored or stopped 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 struck more than 80 Iranian targets and reimposed oil sanctions, and President Trump declared the ceasefire over on July 8. On July 8 and 9 US forces struck Iranian coastal cities on consecutive nights, and Iran retaliated with ballistic missile strikes on US bases in Jordan, Qatar, Bahrain, and Kuwait. A limited and contested trickle of transits has since resumed under continuing strikes, while diplomacy has shifted to an Oman-mediated track in Muscat, where Oman has floated separate inbound and outbound shipping lanes and a navigational-fee framework that Washington opposes and Tehran has resisted, and the United States presses Iran to publicly declare the strait open to all traffic. In the days since, the strikes have continued through further US rounds and a renewed wave of Iranian attacks off Oman that set a container ship ablaze and hit a second vessel, and Iranian retaliation has widened to US logistics on Omani soil. Iran has again declared the strait closed until further notice, even as Iran and Oman have agreed to keep the Oman-mediated talks on shipping security going. Into July 13 the fighting has intensified further: US forces have carried out a fourth wave of strikes on Iranian missile and drone sites near the strait, both sides now claim control of the waterway, Iran has fired warning shots at merchant ships attempting passage, and transits have fallen to their lowest level in several weeks. 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.