The Strait of Hormuz is 21 miles wide at its narrowest point. Through it passes roughly 20% of the world’s oil and a similar share of its liquefied natural gas. It is, by any measure, the single most important chokepoint in the global economy. And as of this week, it is effectively closed.

The US government is scrambling. CNN reports that American officials are “furiously” working to avert what could become a monthslong closure. Treasury Secretary Scott Bessent told Sky News that the US Navy will escort oil tankers through the strait “when militarily possible” — a caveat that tells you everything about how dangerous the waterway has become.

Iran's Strategic Masterstroke

When the US and Israel launched strikes against Iran on February 28th, the assumption in Washington was that Tehran’s conventional military capabilities would crumble quickly. That assessment proved correct for Iran’s air defences and missile launchers. But it missed the asymmetric response that Iran had clearly war-gamed for decades: close the strait.

Iran’s IRGC has been blunt. A spokesperson declared that “not a litre of oil” would pass through Hormuz, and warned to “expect oil at $200 per barrel.” The strait isn’t technically closed to all traffic — Iran’s foreign minister clarified that it was only closed to ships controlled by “the country’s enemies” — but in practice, almost no commercial shipping is willing to risk the passage. Insurance premiums for tankers transiting the strait have become prohibitive.

The Numbers Are Terrifying

The scale of the disruption is staggering. An estimated 20 million barrels per day is backed up behind the closure, with only about 5 million finding alternative routes through pipelines. Brent crude has surged past $145. About a third of all fertiliser shipped globally transits the strait, meaning the closure threatens not just energy prices but the global food supply.

The IEA has released 400 million barrels from emergency reserves — the largest coordinated release in history — but this is a temporary measure. Strategic reserves are finite. If the closure persists for months, as some analysts now fear, no amount of reserve releases will be sufficient.

Why the Navy Can't Fix It

The US Navy is the most powerful maritime force in human history. But reopening the Strait of Hormuz by force is not a simple naval operation. Iran has seeded the waters with mines. Its coastal missile batteries, while degraded by airstrikes, have not been eliminated. And its fleet of small fast-attack boats, while no match for a carrier group in open water, are lethal in the confined geography of the strait.

Escorting tankers through a mined, missile-threatened waterway under constant threat of swarm attacks is not the kind of operation you undertake lightly. Bessent’s caveat — “when militarily possible” — is an admission that it may not be possible soon.

The 1973 Parallel

Historians will compare this to the 1973 Arab oil embargo, and the comparison is apt. But there is a critical difference. In 1973, the embargo was a deliberate political choice by oil-producing nations. This time, the supply disruption is a consequence of a war that the US chose to start. Washington engineered the strikes on Iran. Tehran responded by weaponising the chokepoint that everyone knew it controlled. The economic fallout is not an unintended consequence — it was the most predictable consequence imaginable.

And yet, somehow, no one in the administration appears to have planned for it.