Iran Declares Hormuz Closed, Says It Has Struck Ships in Strait

Tehran announced the closure of the Strait of Hormuz to all shipping late Tuesday and said its forces had struck vessels transiting the waterway, hours after a second US strike package targeted Iranian nuclear and military sites. The declaration marks the first time in the current cycle that the Iranian government has moved from threat to claimed action against shipping in the strait.

Iranian state media did not name the vessels said to have been hit, give their flags, or specify the weapons used. The Pentagon, for its part, said the latest American round of strikes was now “completed”, language that places Iran’s response — not further US action — as the immediate variable. Earlier in the day Iran retaliated against US installations in Bahrain and Jordan; the Hormuz move is a separate, maritime axis of escalation.

The Iranian government denied a claim by President Trump that Iranian officials had reached out to the White House through back channels. The country’s top joint military command said Iranian armed forces were ready to deliver a “crushing and decisive” response to further US action. Read together, the two statements rule out a near-term off-ramp from Tehran’s side. The earlier US strike package — covered in our Hegseth “key facilities” report — explicitly targeted sites the Defense Secretary said were tied to Iran’s nuclear program, raising the threshold for any quiet de-escalation.

What “closing” Hormuz actually means

Iran has no legal authority to close the Strait of Hormuz. The waterway is an international strait under the UN Convention on the Law of the Sea, and the right of transit passage applies to all vessels, including warships. What Iran can do — and has warned it will do — is make transit operationally untenable. The tool kit is well understood: naval mines laid from small craft, anti-ship cruise and ballistic missiles fired from the Iranian coast, and IRGC Navy fast-attack swarms operating out of bases on Qeshm, Larak, and Bandar Abbas.

Roughly a fifth of the world’s seaborne crude oil moves through the strait, along with the bulk of Qatari LNG exports. Even a sustained insurance and war-risk spike — without a single additional ship hit — is enough to force tanker owners to reroute, slow-steam, or refuse charters into the Gulf. Our earlier piece on the Kuwait tanker fire and oil’s spillover move covered the price reaction before the formal closure declaration; tonight’s announcement raises the baseline.

US Navy posture and the escort question

The US Fifth Fleet, headquartered in Manama, is the standing American naval command for the Gulf. Bahrain itself was a target in Iran’s earlier retaliation, complicating the host-nation picture even as the fleet remains operational. The Trump administration has floated the idea of US Navy escorts for tankers transiting the strait — an arrangement reminiscent of the 1987-88 reflagging operations during the Tanker War. Al Jazeera analysts argued Tuesday that the escort proposal will not, by itself, ease the crisis: convoys do not address mines already laid, do not shorten the missile envelope from the Iranian coast, and tie up high-end US surface combatants in a narrow chokepoint where they are themselves vulnerable.

Additional assets that can plausibly surge into the region include a second carrier strike group, mine countermeasures ships forward-deployed from Bahrain, and patrol aircraft out of Gulf partners — though the Gulf itself is split on how to respond, with Saudi Arabia condemning Iran and Qatar pushing mediation. Basing access for any sustained US escort or strike tempo will be a political variable, not just a military one.

Market read-across

Crude futures were bid higher in thin overnight trading on the closure headlines, defense names traded firm in after-hours, and equity index futures softened on risk-off positioning. The size of the moves will depend on what the Asian open does with the news and whether further ship incidents are reported overnight Gulf time. We are not citing specific price levels here because the cash markets are not open and overnight prints are unreliable.

What to watch

• Tanker AIS data at Wednesday’s local-morning Gulf tide window — actual transits, diversions, and any signs of vessels held at anchor outside the strait.
• A CENTCOM readout updating on the Pentagon’s “completed” framing, and any change in posture from the Fifth Fleet.
• Iranian follow-on attacks against US bases in the Gulf and Levant, beyond the earlier Bahrain and Jordan strikes.
• Insurance and war-risk premium quotes from the London market.

The wider diplomatic backdrop has been deteriorating for days. The IAEA Board of Governors passed a censure resolution earlier this week, which Iran rejected outright while declaring it would not disclose uranium stocks. The collapse of the latest nuclear track, the second US strike package, and now the Hormuz closure declaration belong to the same escalation sequence — one in which, by Tehran’s own statements tonight, the next move is Iran’s to make.