The Strait of Hormuz, a vital artery for global oil shipments, has long served as a powerful geopolitical tool for Iran, which has repeatedly threatened to shut the narrow waterway during periods of heightened tension.
Tehran once again raised the possibility of closure after Israel launched a large-scale air offensive earlier this month targeting Iranian nuclear and military installations. The United States followed with strikes against key Iranian nuclear facilities on Sunday.
Some Iranian lawmakers have publicly floated the idea of closing the Strait in response to US military action. However, any decision lies with Iran’s National Security Council, its highest security authority.
Despite decades of sabre-rattling, Iran has never actually carried out its threats to block the strait.
The Strait of Hormuz connects the Gulf with the Indian Ocean, lying between Iran and Oman’s Musandam peninsula. Its narrowest point spans just 50 kilometres (30 miles), and its relatively shallow depth of around 60 metres (200 feet) makes it especially vulnerable to military disruption.
The area is dotted with sparsely inhabited islands, many of which hold strategic significance. These include Iran’s Hormuz, Qeshm, and Larak islands, as well as the disputed Greater Tunb, Lesser Tunb, and Abu Musa islands, which have been under Iranian control since 1971.
The strait serves as a key conduit for oil-rich Gulf states, connecting their exports to markets across Asia, Europe, North America, and beyond.
The US Energy Information Administration (EIA) describes the Strait of Hormuz as “one of the world’s most important oil chokepoints.” In 2024, an estimated 20 million barrels of oil and petroleum products pass through the strait daily, accounting for roughly one-fifth of global consumption.
It is also a major route for liquefied natural gas exports, particularly from Qatar, which uses the strait to supply global markets.
While Saudi Arabia and the UAE have developed infrastructure to partially bypass the strait, their alternative routes have limited capacity, able to handle just 2.6 million barrels per day.
“Large volumes of oil flow through the strait, and very few alternative options exist if it is closed,” the EIA cautioned.
Despite frequent threats, many analysts believe that physically closing the strait would bring severe consequences for Iran itself. More than 80 per cent of the oil and gas flowing through the strait is destined for Asian markets. China, Iran’s key economic partner, purchases over 90 per cent of Iranian oil exports, according to reports.
Any disruption would likely alienate Iran’s remaining allies and severely harm neighbouring Gulf Cooperation Council countries and Iraq.
Iran’s elite Revolutionary Guard Corps controls naval operations in both the Gulf and the Strait of Hormuz. Tehran has consistently criticised the presence of foreign military forces in the region, which hosts the US Fifth Fleet in Bahrain and Washington’s largest Middle Eastern base in Qatar.
Last year, the Revolutionary Guard seized a cargo vessel transiting the strait, claiming it had links to Israel, following a deadly attack on Iran’s consulate in Syria blamed on Israel.
Western naval forces have repeatedly warned commercial ships against approaching Iranian waters in the strait to reduce the risk of seizure. These warnings have grown more frequent since 2018, when US President Donald Trump broke from the nuclear deal with Iran and reimposed severe sanctions, triggering a surge in tensions.
Oil shipping was previously disrupted during the Iran-Iraq War in the 1980s, when both nations targeted commercial vessels in what became known as the “Tanker War,” damaging or destroying more than 500 ships.
