The geopolitical temperature around the Strait of Hormuz has spiked sharply following Iran’s renewed threats to close the waterway, a chokepoint for approximately 20% of the world’s oil. The strait, a narrow artery between the Arabian Peninsula and Iran, is the conduit for roughly 17 million barrels of crude per day. Any sustained closure would be a body blow to global energy markets, triggering price spikes that would compound existing inflationary pressures. The United Kingdom, alongside the United States, has begun marshalling naval assets to ensure freedom of navigation, a move that carries echoes of the Tanker War in the 1980s. The situation is fluid, but the science of energy security and climate risk demands a clear-eyed analysis.
Iran’s motivations are a tapestry of domestic pressure and negotiating leverage. The country faces severe economic strain from sanctions, and the threat of closure is a high-stakes gamble to extract concessions in nuclear talks. But the physical reality of the strait is unambiguous: it is shallow, at only 60 metres deep in parts, and narrow, with a shipping lane just 3 kilometres wide. The Islamic Revolutionary Guard Corps has a fleet of fast attack craft, anti-ship missiles, and sea mines. A single mine strike can cripple a supertanker, and the ensuing spill would cripple desalination plants along the Gulf, affecting millions. The current escalation follows a series of seizures and attacks on commercial vessels in recent years, which have already increased insurance premiums for transiting ships by 10%.
The global energy system is already under duress. The transition to renewables is accelerating, but we remain tethered to fossil fuels. The International Energy Agency’s latest outlook shows oil demand still rising, albeit more slowly. A Hormuz closure would remove 4% of global supply overnight, a shock comparable to the 1973 oil embargo. The British naval response, centred on the Type 45 destroyer HMS Duncan and support vessels, is a deterrent but not a guaranteed remedy. The Royal Navy has not operated at this scale in the region since the Iran-Iraq War. The House of Commons Defence Committee warned last year that the navy’s surface fleet is stretched thin. One hopes diplomacy prevails, but the physical reality is that if mines are laid, clearing them takes weeks, not days.
The climate dimension adds a grim irony. The Strait of Hormuz’s vulnerability is a reminder that our dependence on fossil fuels creates systemic risks. Every barrel of oil that passes through there will be burned, adding to atmospheric CO2. The UK’s own net-zero target by 2050 requires a rapid phase-out of fossil fuels, but we still import oil from Gulf states. The current crisis should accelerate investment in domestic renewables and storage. But in the immediate term, the priority is de-escalation. The science of conflict tells us that signals matter: a visible naval presence can reduce the odds of miscalculation. But if the strait closes, the economic fallout will be measured in trillions of dollars, and the human cost in darkened homes and stalled hospitals.
The next 48 hours are critical. The British foreign secretary has called for an emergency UN Security Council meeting. Meanwhile, the US has reportedly offered Iran sanctions relief in exchange for de-escalation. The ball is in Tehran’s court. For the rest of us, it is a stark lesson in energy vulnerability. The planet’s climate and geopolitical systems are intertwined, and our addiction to cheap oil is the thread that binds them. The Strait of Hormuz is not just a waterway; it is a stress test for the global order. We must hope it does not fail.
