Why the Strait of Hormuz matters so much in the Iran war
Strategic Significance of the Strait of Hormuz in Regional Conflicts
The recent agreement between Iran and the United States to halt hostilities hinges on the assurance of unimpeded navigation through the Strait of Hormuz. This critical waterway, which Iran had effectively closed since the U.S. and Israel launched an assault on the country on 28 February, serves as a linchpin for global energy trade. Approximately 20% of the world’s oil and liquefied natural gas (LNG) typically flows through the strait, and its blockage had caused fuel prices to spike dramatically.
Following the ceasefire announcement, global oil prices dropped by roughly 15%, signaling a temporary reprieve for energy markets. The strait, flanked by Iran to the north and Oman and the United Arab Emirates (UAE) to the south, is a narrow passage—measuring just 50 kilometers at its entrances and 33 kilometers at its narrowest point. Its depth allows passage for the largest crude oil tankers, making it a vital link between the Gulf and the Arabian Sea.
Global Energy Trade and Economic Impacts
Estimates from the U.S. Energy Information Administration (EIA) indicate that in 2025, about 20 million barrels of oil and related products traversed the strait daily, contributing nearly £447bn to annual energy commerce. This includes shipments from Iran, Iraq, Kuwait, Qatar, Saudi Arabia, and the UAE, as well as LNG primarily sourced from Qatar. In 2024, Qatar exported around 9.3 billion cubic feet per day (Bcf/d) of LNG through the strait, with the UAE contributing 0.7 Bcf/d, according to U.S. government data.
Additionally, the strait plays a key role in the transport of fertilizers, with one-third of global trade passing through it. It is also essential for importing goods such as food, medicines, and technology to the Middle East. Normally, around 3,000 vessels navigate the waterway each month, but recent tensions saw this number plummet as Iran threatened to target commercial ships and tankers.
Risks and Military Responses
Under international law, countries can control territorial seas up to 12 nautical miles from their coasts. At the strait’s narrowest point, both Iran and Oman’s territorial waters encompass the shipping lanes, creating a high-risk corridor for maritime traffic. Iranian forces, including drones, missiles, and fast attack boats, posed a significant threat to vessels passing through. As of 2 April, United Against Nuclear Iran reported at least 24 commercial ships had been struck, along with three near-misses.
“You can be attacked, and you can’t get insurance or it is extremely expensive,” said Arne Lohmann Rasmussen, chief analyst at Global Risk Management, during the period of instability.
The U.S. has opted for air strikes rather than deploying warships to the strait, targeting Iranian facilities. On 18 March, U.S. forces bombed anti-ship missile sites near the waterway. Former President Trump had previously urged allies and even China to bolster security by sending warships, but his call received limited support. He later asserted the U.S. did not require external assistance to safeguard the strait.
Historically, the strait has been a focal point of conflict. During the late 1980s Iran-Iraq war, strikes on oil infrastructure escalated into a “tanker war,” where both nations attacked neutral ships to pressure economies. Kuwaiti tankers transporting Iraqi oil were particularly vulnerable. Today, the strait remains a strategic asset, with its disruption affecting not only the Middle East but also regions like Asia and Europe. For example, China accounts for nearly 90% of Iran’s oil exports, and fuel shortages have led to measures such as reduced working hours, school closures, and rationing in countries like Slovenia.