Strait of Hormuz 'faultline' exposes weakness of the US-Iran deal

The Strait of Hormuz has become the most dangerous body of water in the world, and the crisis unfolding there is exposing the fragility of the agreement that was supposed to prevent exactly this scenario.

The US-Iran deal, brokered in 2025 after months of shuttle diplomacy, was hailed as a breakthrough that would stabilise the Middle East and secure the free flow of oil through the world's most important maritime chokepoint. In exchange for sanctions relief and security guarantees, Iran agreed to limit its nuclear programme, restrain its proxies and respect freedom of navigation in the Gulf.

Eighteen months later, that deal is in tatters. Iranian-backed militias have resumed attacks on commercial shipping. The United States has responded with air strikes. Iran has threatened to close the strait entirely. Oil prices have spiked, and the global economy is once again hostage to a crisis that the deal was designed to prevent.

The weakness exposed by the crisis is not primarily military — the US Navy retains overwhelming superiority in the Gulf — but political. The deal's enforcement mechanisms were always its weakest component. Iran's compliance was to be verified by international inspectors, but there was no credible mechanism for responding to violations short of the military escalation that the deal was meant to avoid. When Iran began testing the boundaries, the architecture proved insufficient.

The crisis also exposes a deeper strategic problem: the United States no longer has the leverage over the Middle East that it once did. China is Iran's largest trading partner and its most important diplomatic ally, and Beijing has shown no interest in pressuring Tehran to comply with an agreement it did not negotiate. The result is a crisis without a clear diplomatic off-ramp — precisely the situation the architects of the deal promised would never arise.