US Prepares to Clear Iranian Mines in Strategic Strait of Hormuz
Former President Donald Trump has announced plans to initiate anti-mine operations in the Strait of Hormuz, as part of a broader effort to reopen this critical maritime passage. The strait has been effectively closed to marine traffic by Iran since the United States and Israel launched their war in late February, creating a significant disruption to global shipping routes.
Iran's Minelaying Strategy and Capabilities
With much of its large naval fleet destroyed by US and Israeli strikes, Iran has turned to small surface vessels to deploy mines in key areas of the Strait of Hormuz. The exact number of mines laid remains unknown, but Iran has reportedly left a narrow passage open for ships willing to pay a toll. According to US officials cited by the New York Times, Iran has indicated it cannot locate all the mines it has deployed and lacks the capability to remove them effectively.
These mines represent just one component of Iran's offensive arsenal in the strait, which also includes cheap drones, anti-ship missiles, and fast-attack small vessels. The Islamic Revolutionary Guard Corps showcased some of these capabilities in a propaganda video filmed in a naval bunker in January 2025, highlighting their small vessel and mine-laying capacity.
Types of Mines Deployed by Iran
Iran is believed to have deployed two primary types of mines: the Maham 3 and the Maham 7. Both are modern varieties that use magnetic and acoustic sensors to detect nearby ships before detonating, unlike older models that required physical contact with a ship's hull.
- Maham 3: An anchored mine weighing 300kg, capable of operating in waters up to 100 meters deep.
- Maham 7: A bottom-resting mine weighing 220kg, designed for shallower waters with a conical shape to evade sonar detection on the seabed.
Analysis suggests that despite significant losses to its navy, Iran retains 80% to 90% of its small boats and mine-layers, allowing for potential additional mining if the conflict continues.
US Clearance Options and Associated Risks
Clearing mines is a laborious and dangerous process, even though laying them is relatively quick and easy. The mined passage in the narrow strait covers a large area, making crewed US minesweepers vulnerable targets if hostilities resume.
The most effective and least risky option for the US involves using uncrewed marine mine-hunting vehicles, such as:
- Knifefish undersea mine hunter: A submersible device designed to detect and neutralize mines.
- MCM anti-mine vessel: A speed boat-like platform equipped for mine clearance operations.
Additionally, the US could deploy the AN/ASQ-235 (Archerfish) airborne mine neutralization system from MH 60S helicopters. This system uses sonar-equipped vehicles to detect and destroy mines, controlled remotely by helicopter crews.
While uncrewed systems reduce direct danger to personnel from mines, they require close proximity from US ships and aircraft for launch and control, exposing personnel to potential missile or drone attacks if the ceasefire ends.
Recent Developments and Legal Considerations
On April 11, two US destroyers—the USS Frank E Petersen and USS Michael Murphy—transited the strait, with US Central Command describing the move as "setting conditions for clearing mines." Tehran's response to more sustained operations remains uncertain, as does the potential impact on the current ceasefire.
The global economy's reliance on maritime trade gives mine-laying countries disproportionate leverage, as even a small number of mines can close sea lanes. Some mines can be programmed to detonate after a specific number of ships pass, creating uncertainty and amplifying their disruptive effect.
International law complicates the situation, as neither Iran nor the US is a party to the 1994 UN Convention on the Law of the Sea. While international law prohibits using mines to close international straits for innocent passage, Iran claims part of the strait as its territorial waters. It is unclear whether Iran would be required to provide a detailed mine map to the US, given the ongoing armed conflict and the US's own military blockade measures.
