Why the Strait of Hormuz matters so much in the Iran war
Why the Strait of Hormuz matters so much in the Iran war
The United States and Iran reached an agreement to halt hostilities, provided “safe passage” through the Strait of Hormuz remains assured. This critical waterway, which links the Gulf of Oman to the Arabian Sea, had been effectively controlled by Iran since its attack on the country by the US and Israel on 28 February. As one of the world’s most vital shipping lanes for oil, the strait saw a sharp rise in global fuel prices due to the ongoing tensions. Following the ceasefire announcement, oil prices dropped by approximately 15%, signaling a temporary easing of the crisis.
A Strategic Waterway
Bounded to the north by Iran and to the south by Oman and the United Arab Emirates (UAE), the strait measures about 50km in width at its entrances and narrows to 33km at its most constricted point. This passage is essential for connecting the Persian Gulf with the Arabian Sea, and its depth allows the largest crude oil tankers to traverse without issue. Major oil and LNG producers across the Middle East, along with their international clients, rely on this route for global trade.
Economic Significance
Approximately 20% of the world’s oil and liquefied natural gas (LNG) transits through the strait, according to the US Energy Information Administration (EIA). In 2025, around 20 million barrels of oil and related products moved daily, valued at nearly £447bn annually. Iran’s exports are a key part of this flow, but shipments also originate from Iraq, Kuwait, Qatar, Saudi Arabia, and the UAE. Additionally, about one-third of global fertiliser trade passes through the strait, with significant volumes coming from Middle Eastern producers.
Threats to Maritime Traffic
During the conflict, the number of ships navigating the strait plummeted as Iran threatened to target tankers and commercial vessels. The waterway lies entirely within Iran and Oman’s territorial waters at its narrowest point, making it a strategic area for attacks. Iranian drones, missiles, and fast attack boats created a dangerous environment, with reports of at least 24 commercial ships being struck and three near misses by 2 April, as documented by the non-profit United Against Nuclear Iran.
“Vessels can be attacked without adequate insurance, or at a steep cost,” said Arne Lohmann Rasmussen, chief analyst at Global Risk Management, during the period of instability.
Historical Context
Historically, the strait has been a focal point of global energy conflicts. In the late 1980s, during the Iran-Iraq war, strikes on oil infrastructure led to a “tanker war,” where both nations targeted neutral ships to disrupt trade. Kuwaiti tankers carrying Iraqi oil were particularly at risk. The US later deployed warships to safeguard the route, a strategy that may be repeated in the current scenario. On 18 March, the US military reported bombing Iranian anti-ship missile sites along the strait as part of its broader military response.
While the US has not stationed warships in the strait, it has targeted Iranian positions from the air. Former President Trump previously urged allies and China to assist in securing the passage, but his call for military support faced limited support. He later argued that the US could manage the situation independently. The current crisis has also impacted Asia, with China accounting for roughly 90% of Iran’s oil exports to the global market. Across the region, governments have implemented measures to reduce energy consumption, including remote work mandates, shortened workweeks, and early university closures.
Meanwhile, in Europe, Slovenia became the first EU country to enforce fuel rationing amid the supply challenges. The strait remains a lifeline for Gulf states, which depend on energy exports for national income. Its disruption not only threatens regional economies but also disrupts daily life for millions, as fuel shortages continue to affect transportation and heating needs.
