Tehran has escalated its rhetoric over the Strait of Hormuz, the narrow waterway through which 20% of the world's oil transits. The Iranian Revolutionary Guard Corps announced on Tuesday that it will “assert full control” over the strait, a move that analysts describe as a direct challenge to international maritime law and a clear threat to global energy supplies.
The strait connects the Persian Gulf to the Gulf of Oman, forming a crucial chokepoint for crude oil and liquefied natural gas exports from Saudi Arabia, Iraq, Kuwait, the UAE, and Iran itself. Any disruption here would send shockwaves through energy markets, spiking prices and jeopardising economic stability. The timing is particularly concerning: global oil inventories are already tight, and the International Energy Agency has warned that supply could struggle to meet demand this winter.
Iran's claims are not new. Since the 1979 revolution, it has periodically asserted sovereignty over the strait, often in response to geopolitical pressure. The difference now is the bluntness of the language. General Hossein Salami, commander of the IRGC, stated that the strait is “100% under our control” and that Iran will “determine who passes through”. This is not a legal claim but a military posture. It suggests that Iran believes it can dictate terms to the world’s shipping lanes.
The international response has been swift. The United States Fifth Fleet, based in Bahrain, reaffirmed its commitment to freedom of navigation. “The Strait of Hormuz is an international waterway and must remain open to all lawful traffic,” said a spokesperson. The UK’s Royal Navy has also maintained a presence, but the resources are stretched. A prolonged standoff could test the capacity of naval coalitions to keep the lane open.
For the physical world, the implications are immediate. Tanker insurance premiums for voyages through the strait have already risen by 20% this month. Shipping companies are quietly rerouting vessels around the Cape of Good Hope, adding two weeks to transit times and increasing fuel consumption. This is a worst-case scenario for climate watchers: longer routes mean higher emissions. A blockade would undo years of progress in reducing maritime carbon intensity.
The Strait of Hormuz is 21 miles wide at its narrowest point, but the shipping lane is only about two miles in each direction. It is a target as vulnerable as it is vital. Iran possesses anti-ship missiles, fast attack boats, and mines. A single mine could close the channel for days. A coordinated attack could shut it for weeks. This is not hyperbole; it is physics.
The energy market has already begun to price in the risk. Brent crude futures jumped 4% on the news. The fear is not just of a blockade, but of a miscalculation that leads to direct confrontation. Tehran’s economy is suffocated by sanctions; control of the strait is its only leverage. It is a dangerous game of brinksmanship with no easy exit.
What can be done? Diplomacy must be the first line. The Joint Comprehensive Plan of Action, or nuclear deal, was designed in part to stabilise the region. Its collapse has left a vacuum. Without a framework for negotiation, Iran will continue to push. The alternative is a military escalation that nobody wants.
For now, the tankers keep moving. But the temperature has risen. The Strait of Hormuz is not just a waterway; it is a pressure gauge for global stability. And the needle is in the red.
