Britain has taken a leading role in organising international pressure over the closure of the Strait of Hormuz, the critical waterway through which roughly a fifth of the world’s oil and gas passes. Foreign Secretary Yvette Cooper convened a virtual meeting of more than 40 countries on 2 April 2026, with the aim of building a coordinated response to what she described as an unacceptable threat to global economic security.
Why the Strait of Hormuz Matters
The Strait of Hormuz is one of the most strategically important chokepoints in the world. Situated between Iran and Oman, it connects the Persian Gulf to the Gulf of Oman and from there to global shipping lanes. Approximately 20 percent of the world’s oil supply passes through the strait, along with a significant proportion of liquefied natural gas, particularly supplies destined for Europe and Asia.
Since the outbreak of conflict between the United States, Israel and Iran in late February 2026, the strait has effectively been closed to commercial shipping. Iran’s Islamic Revolutionary Guard Corps has issued warnings against vessel passage and has carried out attacks on merchant ships, causing tanker traffic to drop sharply. More than 150 vessels have been anchored outside the strait waiting for conditions to improve. Brent crude oil prices have surpassed $126 per barrel as a result, with further increases anticipated.
The Coalition Meeting
The virtual meeting convened by Yvette Cooper brought together foreign ministers and senior officials from over 40 countries spanning every continent. Key international bodies, including the International Maritime Organisation and the European Union, also participated. Notably, the United States did not take part — an absence that underlines the complexity of the diplomatic situation, given that Washington is a primary party to the conflict.
Cooper told participants that Iran’s behaviour was “hitting our global economic security” and called for collective action to reopen the waterway. The coalition agreed to pursue coordinated diplomatic pressure through the United Nations, explore economic and political measures including sanctions if the strait remains closed, and work with the IMO to secure the release of ships and crews trapped in the strait.
Starmer’s Role and the UK’s Diplomatic Position
Prime Minister Keir Starmer has been careful to maintain a distinct British position from that of the United States throughout the Iran conflict. While expressing solidarity with US allies and condemning Iranian aggression, the UK has not participated directly in military operations. Instead, Starmer has sought to position Britain as a diplomatic bridge — active in seeking a resolution while avoiding direct military entanglement.
The Hormuz coalition effort is central to this strategy. By leading a broad multilateral initiative, Britain signals its continued relevance as a global diplomatic actor after the post-Brexit recalibration of its foreign policy. Cooper’s meeting drew participation from countries across Asia, Africa, Europe and Latin America, suggesting genuine breadth to the coalition even if its practical leverage remains uncertain.
Can the Coalition Work?
The honest answer is that it faces significant obstacles. Iran has shown little sign of responding to diplomatic pressure alone, and without American involvement, any negotiations carry reduced weight in Tehran’s calculus. The coalition’s toolkit — diplomatic pressure, potential sanctions, IMO engagement — falls short of the military options that might force a faster resolution.
There are also questions about unity within the coalition. Countries dependent on Iranian oil, or those with close economic ties to Tehran, may be reluctant to apply meaningful sanctions pressure. The practical mechanics of “coordinated action” across 40 diverse nations are also genuinely complex.
Nevertheless, the initiative has been welcomed by shipping industry bodies and energy importers who are desperate for any sign of progress. For Britain, which is facing sharply higher petrol prices and energy costs as a direct consequence of the Hormuz closure, the stakes could hardly be higher. Whether Cooper’s coalition can translate diplomatic ambition into concrete results is the question the world’s energy markets are watching closely.