What is a naval blockade and how would it work in Strait of Hormuz?

What is a Naval Blockade and How Would It Work in the Strait of Hormuz?

The United States military has announced plans to enforce a maritime blockade targeting all vessels accessing Iranian ports. This measure aims to restrict traffic in and out of the country’s coastal areas. However, the U.S. has stated that ships traveling to and from non-Iranian destinations will still be permitted to pass through the Strait of Hormuz, a vital chokepoint for global trade.

The decision follows stalled negotiations between the U.S. and Iran to resolve the ongoing conflict. Talks in Pakistan, which began on 28 February, ended without agreement. President Donald Trump attributed the failure to Iran’s refusal to relinquish its nuclear aspirations. In response, Iran’s foreign ministry spokesman accused the U.S. of imposing “excessive demands” and making “unlawful requests.”

“BLOCKADING any and all Ships trying to enter, or leave, the Strait of Hormuz,” Trump declared on social media. He emphasized that the U.S. Navy would intercept vessels in international waters that paid tolls to Iran. “No one who pays an illegal toll will have safe passage on the high seas,” he added.

According to the U.S. Navy Commander’s handbook from 2022, a blockade is defined as a “belligerent operation to prevent vessels and/or aircraft of all States, enemy and neutral, from entering or exiting specified ports, airfields, or coastal areas belonging to, occupied by, or under the control of an enemy State.” The U.S. initially claimed the blockade would take effect “effective immediately,” but later clarified it would be implemented “pretty soon” after Monday.

The U.S. Central Command (Centcom) confirmed the blockade’s start time as 10:00 EDT (15:00 BST) on Monday. It stressed that the action would be impartial, applying to vessels of all nations. Centcom also noted that commercial mariners would receive a formal notice before the operation begins, ensuring clarity on its scope.

While the U.S. hinted at international collaboration, the UK has not committed to participating. A UK Government spokesperson affirmed support for freedom of navigation, stating the Strait of Hormuz “must not be subject to tolling.” They are working with France and other allies to form a coalition defending open maritime routes.

Trump mentioned NATO’s readiness to assist with clearing the strait, suggesting it would be “free to use again in not too long a distance.” He also noted the UK, as a NATO member, would join efforts to deploy minesweepers. The BBC learned that British mine-hunting systems are already stationed in the region.

Legal analysts raised concerns about the blockade’s compliance with maritime law. Some questioned whether the operation could breach the current ceasefire agreement. The strait’s strategic location has long allowed Iran to exert influence by limiting vessel movement and manipulating oil prices. By closing the passage, the U.S. risks disrupting Iran’s revenue streams, though this could provoke escalation.