A Strategic Chokepoint and Its Geography
The Strait of Hormuz sits between Iran to the north and the Musandam Peninsula of Oman to the south, with a small portion of the peninsula under the jurisdiction of the United Arab Emirates. At its narrowest point, the waterway measures just 21 miles across. Shipping lanes within the strait are only 2 miles wide in each direction, a geography that makes the passage inherently vulnerable to disruption by even small naval forces. As the sole sea passage linking the Persian Gulf to the open ocean, the strait has long been considered one of the world’s most critical petroleum chokepoints. For several years leading up to the mid-2020s, a large share of global liquefied natural gas and seaborne oil trade moved through it annually, making it a principal route for energy supplies to Europe and Asia. Several Gulf states depend on the strait as their only maritime outlet. Past Middle East conflicts saw no extended closure of the passage, though Iranian authorities at times threatened to seal it and prepared to lay mines. Those threats gained weight when a later war brought a sustained blockade and a regional crisis centered on the strait. The current closure revives the risk that the route’s status shapes energy security well beyond the Gulf.
Sequence of Escalation
The closure follows a series of incidents that have heightened tensions in the region. On March 23, 2025, the United States carried out airstrikes on IRGC positions in Syria. On April 15, 2025, Iran seized a commercial tanker in the Strait of Hormuz. The IRGC’s announcement of the indefinite closure came on April 28, 2025. The IRGC itself was established in 1979 after the Iranian Revolution and operates its own naval forces separate from Iran’s regular navy. Rear Admiral Alireza Tangsiri has led the IRGC Navy since 2018, and his forces have previously threatened to close the strait in response to sanctions or military actions. The United Nations Convention on the Law of the Sea, which Iran signed in 1982 but has not ratified, guarantees passage through international straits. The U.S. Fifth Fleet, based in Bahrain, has not yet issued a formal response to the closure, according to available reports. The disruption of oil shipments through the Strait of Hormuz could affect global supplies, prices, and shipping routes. With 17 million barrels of oil passing through daily in 2023, the loss of that volume represents a significant shock to markets.
Global Consequences and Uncertain Outlook
The impact of shutting down the Strait of Hormuz extends far beyond the immediate region. Major economies in Europe and Asia rely heavily on petroleum and liquefied natural gas that transits the waterway. A prolonged closure would force alternative shipping routes, likely increasing transport costs and delivery times. Global oil markets, already sensitive to supply interruptions, face the prospect of rapid price increases. The 17 million barrels per day that moved through the strait in 2023 accounted for about one-fifth of the world’s oil consumption, according to the U.S. Energy Information Administration. Any sustained loss of that volume would test strategic petroleum reserves and could prompt diplomatic and military responses from consuming nations. The situation remains fluid. For now, the strait stays closed.
