The United States and Iran traded airstrikes overnight on Friday, marking the first direct military exchange since the two adversaries signed a memorandum of understanding on 17 June aimed at ending the broader Middle East war. US Central Command confirmed it struck Iranian missile and drone storage sites and coastal radar installations in response to what it described as an unprovoked Iranian attack on a commercial vessel transiting the Strait of Hormuz a day earlier. Hours later, Iran’s Islamic Revolutionary Guard Corps (IRGC) Navy announced it had retaliated by hitting US military positions in the region, warning that any repeat of American aggression would trigger a wider response.

Each side framed the other as the violator of the ceasefire. Washington, through CENTCOM, said the Iranian drone strike on the merchant ship constituted a clear breach of the truce. Tehran, in a foreign ministry statement, condemned the US strikes as a ‘blatant violation’ of both the first clause of the memorandum and Article 2(4) of the UN Charter, while asserting its inherent right to self-defence under Article 51. The IRGC Navy further invoked Article 5 of what it termed the ‘Islamabad Memorandum of Understanding’, claiming it grants Iran sole responsibility for managing transit through the Strait of Hormuz, and accused the US of inciting other parties to circumvent that authority.

The confrontation has thrust the strategic waterway back to the centre of regional tensions. Iranian state television reported that the IRGC Navy would deal firmly with any vessel not following Iran’s designated routes, and that all ships must coordinate with its forces to enter or exit the strait. Bahrain and several Arab states condemned what they called an Iranian drone attack on their territory, describing it as a violation of sovereignty. The UK Maritime Trade Operations reported a projectile strike on a tanker in the area, causing damage but no casualties. Meanwhile, oil prices fell sharply as shipping data showed Saudi Aramco resuming crude loadings at Ras Tanura after a four-month pause and fertilizer shipments rebounding, suggesting markets were not yet pricing in a prolonged disruption.

The incident tests the durability of the memorandum, which was brokered to halt a conflict that began with US and Israeli strikes on Iran on 28 February. Under its terms, the two sides agreed to settle the disposal of Iran’s stockpile of 440 kilogrammes of uranium enriched to 60 percent, with a mechanism to be agreed that would at minimum involve diluting the material under International Atomic Energy Agency supervision. IAEA Director General Rafael Grossi has cautioned that any final settlement would require robust guarantees to prevent Iran from acquiring a nuclear weapon, a point of persistent disagreement. Iran’s foreign ministry called on the UN Secretary-General and Security Council to address the US violation, while Washington’s deputy president warned that ‘violence will be met with violence’ if further Iranian attacks occur. With negotiations for a permanent settlement ongoing, the exchange highlights the unresolved contest over control of the Strait of Hormuz and the limited enforcement mechanisms of the interim memorandum.