US Plans Anti-Mine Operations in Strait of Hormuz Amid Iran's Naval Threat
Donald Trump has declared intentions to initiate anti-mine operations in the Strait of Hormuz as part of a broader strategy to reopen this critical waterway. The strait has effectively been closed to marine traffic by Iran since the onset of the US and Israel war in late February, disrupting global shipping routes.
Iran's Minelaying Activities and Capabilities
With much of its large naval fleet destroyed by US and Israeli strikes, Iran has resorted to deploying small surface vessels to lay mines in sections of the Strait of Hormuz. The exact number of mines remains unknown, but Iran has reportedly left a passage open for ships willing to pay a toll. According to US officials cited by the New York Times, Iran has indicated an inability to locate all laid mines and lacks the capacity for their removal.
These mines represent just one component of Iran's offensive arsenal in the strait, which also includes inexpensive 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.
Types of Mines Deployed by Iran
Iran is believed to have utilised two primary mine types: the Maham 3 and the Maham 7. Unlike older models requiring physical contact, these modern mines employ magnetic and acoustic sensors to detect nearby ships before detonating warheads.
- Maham 3: An anchored mine weighing 300kg, operational in waters up to 100 metres deep.
- Maham 7: A bottom-resting mine of 220kg, designed for shallower waters with a conical shape to evade sonar detection on the seabed.
Analysis suggests that despite significant naval losses, Iran retains 80% to 90% of its small boats and mine-layers, enabling further minelaying if hostilities persist.
US Mine Clearance Options and Associated Risks
While mines are quick to deploy, their clearance is a laborious and hazardous process. The mined area in the narrow strait is extensive, posing risks to crewed US minesweepers if hostilities resume.
The safest approach for the US involves deploying uncrewed marine mine-hunting vehicles, such as the Knifefish undersea mine hunter and the MCM anti-mine vessel. Additionally, the AN/ASQ-235 (Archerfish) airborne mine neutralisation system, launched from MH 60S helicopters, uses sonar-equipped vehicles to detect and destroy mines.
Although uncrewed systems reduce personnel danger from mines, they require proximity from US ships and aircraft for launch and control, leaving personnel vulnerable to missile or drone attacks if the ceasefire collapses. In a preparatory move, two US destroyers, the USS Frank E Petersen and USS Michael Murphy, transited the strait on 11 April to set conditions for mine clearance, with Tehran's response to sustained operations remaining uncertain.
Effectiveness and Legal Implications of Modern Mines
Modern mines offer disproportionate leverage due to the global economy's reliance on maritime trade, with low costs for laying mines that can close sea lanes. Some mines are programmable to detonate after a set number of ship passages, creating uncertainty and amplifying their disruptive potential.
International law, complicated by neither Iran nor the US being parties to the 1994 UN Convention on the Law of the Sea, prohibits mining international straits to block innocent passage. Iran claims part of the strait as territorial waters, and it is unclear if Iran must provide a detailed mine map to the US, especially amid an ongoing armed conflict under a ceasefire and US military blockades.
