“In Hormuz, geography and military means work together. The narrow channels restrict manoeuvre, while the relatively shallow waters are ideal for laying mines.”
War has never been merely a matter of raw power or superior firepower. It has always been a matter of how capabilities are employed. The battlespace, as the American strategist Edward Luttwak argues, operates according to a paradoxical logic, where strengths can become weaknesses, and simple tools can constrain a far stronger force when placed in the right environment. The Strait of Hormuz is one of the clearest examples of that logic today. It is a waterway only about 34 kilometres wide at its narrowest point, yet a single small metal mine resting on the seabed or floating near the surface can turn it into a real threat zone for global shipping.
This reality is not only due to the simplicity of the means used to disrupt navigation, but also to how effectively those means function within their environment. In Hormuz, geography and military tools reinforce one another. Narrow shipping lanes restrict manoeuvre, while waters that are only around 60 metres deep in many areas are well suited to mine-laying. Iran’s long southern coastline also allows mines to be deployed by small, fast boats that are difficult to track. Under such conditions, Tehran does not need overwhelming firepower as much as it needs a smart distribution of risk throughout the passage, exploiting an unequal cost equation in which a cheap weapon can impose enormous damage on a much stronger opponent.
That equation was demonstrated clearly in 1988, when the American frigate USS Samuel B. Roberts (FFG-58) struck an Iranian mine in the Gulf. The blast tore a large hole in the hull and broke the ship’s keel. While the mine itself cost no more than US$2,000, repairs to the vessel reached nearly US$90 million. US intelligence estimates that Iran possesses more than 5,000 naval mines, and that it has already begun deploying them in Hormuz, giving it a deeply asymmetric ability to disrupt maritime traffic and raise the cost of military intervention without entering into direct confrontation.
US intelligence estimates that Iran holds more than 5,000 naval mines and has already begun laying them in Hormuz.
On the other side, Washington has an integrated package of mine countermeasure capabilities, with the American littoral combat ship, or LCS, presented as a central tool for breaking this form of deterrence. These ships are designed for operations in shallow waters and complex coastal environments. They are equipped with specialised mine warfare systems and rely on surface and subsurface drones to detect and disable mines in an effort to open safe passages through the strait.
Yet those mines would not be cleared in a neutral environment. Mine-clearing operations would take place under a wide spectrum of threats, including coastal missiles capable of striking naval vessels inside the narrow corridor, fast attack craft able to launch surprise raids, and drone, jamming, or reconnaissance operations that expose ship movements and constrain freedom of action.
Under these conditions, mine clearance becomes a slow and easily interrupted effort, especially when mines can be relaid faster than they are removed. That raises the core question: can these ships impose a safe and stable corridor through the strait, or will the nature of the battle turn every reopening attempt into a temporary measure that ends in failure?
The Evolution of the Naval Mine
The roots of naval mines go back to the fourteenth century, when the Chinese used primitive explosive devices made from sealed animal bladders filled with explosives and ignited by simple fuses. In 1777, the American David Bushnell developed the first modern naval mine by placing a barrel of gunpowder in the Delaware River and fitting it with a detonator that triggered on contact with a solid object, in an attempt to target British ships during the War of Independence. Although the attack did not sink a major ship, it proved that a small hidden charge beneath the water could unsettle an entire fleet.
From that point onward, naval mines developed continuously and accompanied nearly every major war. During the First World War, both the Allies and Germany laid hundreds of thousands of mines. One of the most significant examples was the North Sea Mine Barrage, a vast field stretching for hundreds of miles between Britain and Norway to restrict German ships and submarines. In the Second World War, mines became one of the deadliest naval weapons, sinking large numbers of vessels on all sides. This historical pattern reveals a constant truth: the naval mine is a low-cost weapon with a high impact.
The Four Main Types of Naval Mines
Modern naval mines are broadly divided into four main categories, distinguished by where they are placed in the water and how they are triggered.
Moored Contact Mines
The first type is the moored mine, historically the oldest and most widespread. It consists of a spherical warhead floating just below the surface, tethered by a cable to an anchor on the seabed. The lower portion contains the explosives, while an air pocket in the upper section provides buoyancy. On the outer surface are metal “horns” containing glass ampoules filled with an electrically conductive electrolyte solution. When a ship’s hull strikes one of these horns, the glass breaks, the liquid enters a dry cell, the electrical circuit closes, and the mine detonates. This simple design, developed by the Germans in the early twentieth century, remains effective to this day.
Naval mines fall into four main categories, distinguished by their position in the water and their detonation mechanism.
Floating Mines
The second category is the floating mine, the simplest of all types. It moves freely with the currents and is not anchored to the seabed. Its danger lies in the fact that its path is difficult to predict, which means it can drift far beyond the area where it was originally deployed. The 1907 Hague Convention sought to limit its use because of its inherently uncontrollable nature, but that did not prevent its continued appearance in actual practice. Even a moored mine can turn into a floating mine if its cable is cut, whether by sweeping operations or corrosion, which further increases its threat.
Bottom Mines
The third category is the bottom mine, the most dangerous and sophisticated type. It rests on the seabed, allowing it to carry heavier explosive charges. It does not rely on direct contact. Instead, it operates through what are known as influence systems, detecting the signature of a ship passing overhead through a set of sensors. These include magnetic detectors that sense changes in the Earth’s magnetic field caused by the ship’s metal hull, acoustic hydrophones that pick up engine and propeller noise underwater, and pressure sensors that measure changes in water pressure caused by the ship’s displacement. This combination allows the mine to distinguish between targets, ignore smaller or less significant vessels, and wait for a specific target before detonating.
Modern bottom mines can also be programmed with delay timers that keep them dormant for a period after deployment, and with counters that allow them to ignore a number of signals before activating. These features make them more deceptive. Mine-clearing units may pass over them without triggering them, creating the false impression that an area is safe while the mines remain in place, waiting for the right moment.
Limpet Mines
The fourth category is the limpet mine, named after the sea snail that clings to rocks. This is a small mine manually attached to a ship’s hull by a diver or swimmer using magnets. It is usually detonated by a timer that gives the person who planted it time to withdraw. The British developed it during the Second World War for special sabotage missions. Its purpose is often not to sink a ship outright, but to disable it by targeting the propeller or rudder.
Iranian Readiness and American Underpreparedness
Reports from the US Congress estimate that Iran’s stockpile of naval mines includes a mix of moored contact mines and bottom mines, built up over four decades through both imports and domestic production. In terms of conventional mines, Iran is believed to possess around 2,000 units, including the Sadaf and M-08 mines. The latter was the type that nearly sank the USS Samuel B. Roberts in 1988.
Iran’s more advanced inventory includes bottom mines such as the Russian MDM-6, which carries a heavy warhead of roughly 1,100 kilograms, alongside the MC-52, made with a non-magnetic casing that reduces the chances of detection and complicates sweeping operations, as well as the domestically produced Maham-2.
The most complex threat may be the Chinese-made EM-52, a rising mine.
The most complex threat, however, is the Chinese-made EM-52, a rising mine. It sits on the seabed at depths of up to 200 metres and, when it detects a target, launches a projectile vertically to strike the underside of the ship’s hull. This type combines the stealth advantage of traditional bottom mines with the ability to engage targets at greater depths, significantly expanding the threat envelope. Estimates suggest that deploying such mines may require submarines, such as the Russian Kilo-class boats that Iran operates, indicating a higher level of operational complexity in the use of these systems.
In contrast, reports identify a striking gap in American readiness to confront this type of threat, both in prior assessment and in operational preparedness. While Iran has been developing its mine warfare tools and building its capabilities, Washington has moved in the opposite direction, restructuring its traditional capabilities before fully fielding their replacements.
In September 2025, only months before the current military operation against Iran began, the US Navy withdrew the last four Avenger-class mine countermeasure ships from the Gulf, ending a presence that had lasted for more than three decades. The move was part of a transition towards a new concept of mine warfare based on unmanned systems.
The American mine countermeasure ships arrived in Philadelphia for scrapping at the same time reports began to indicate that Iran was laying mines in the Strait of Hormuz.
The irony is that these vessels arrived in Philadelphia for scrapping at precisely the time reports began to indicate that Iran had started laying mines in the strait. This reflects a timing gap between dismantling older capabilities and activating the new alternatives. The same trend was not limited to the United States. The British Navy took a similar course, withdrawing its last specialised mine-clearing ships from the Gulf earlier in 2026 without sending a direct replacement.
The Avenger ships were built with wooden hulls coated in fibreglass, reducing their magnetic signature and lowering the risk of triggering mines during operations, which allowed them to work inside minefields. Thanks to that design, these vessels helped destroy more than 1,000 mines laid by Iraq off the Kuwaiti coast during the Gulf War in the early 1990s.
America’s New Gamble
The replacement the US Navy is now banking on, the littoral combat ship, differs fundamentally in operating philosophy from dedicated mine countermeasure ships such as the Avenger. Instead of entering the minefield directly, as the Avenger does, the LCS remains outside the threat zone and sends in unmanned systems to perform the work. The package used by these ships combines manned platforms with surface and subsurface drones designed to locate mines, identify them, then disable or destroy them without exposing the ship or crew to direct danger.
In practical terms, the system operates across three integrated levels.
Air Layer
The first is aerial, using Seahawk helicopters launched from the ship’s deck. These helicopters are fitted with an airborne laser mine detection system that scans shallow waters at high speed for floating mines or mines near the surface. In simple terms, it works like a laser beam sweeping beneath the water to reveal unusual objects faster than traditional sensing methods. The helicopter also carries another system that launches a small underwater vehicle towards a detected mine in order to destroy it.
Surface Layer
The second level is surface-based, relying on an unmanned boat that operates as a forward reconnaissance platform for the mothership. This craft can be equipped with advanced sonar to scan the seabed and generate a detailed picture in search of bottom or moored mines. It can also carry a system that mimics the acoustic and magnetic signature of a real ship, with the aim of triggering influence mines before actual naval vessels approach.
Underwater Layer
The third level is underwater. It uses submerged drones designed specifically to detect bottom mines, especially those buried in sediment and difficult to identify by conventional means. These vehicles operate relatively quietly and provide precise localisation of the more complex mine threats.
Systems Unproven in Combat
Despite this theoretical readiness, using these ships in the current context would be unprecedented. The system has not yet been tested in large-scale real-world mine clearance operations under complex combat conditions. The programme has also been troubled from the beginning. Littoral combat ships were designed as fast, flexible, lower-cost platforms capable of switching missions between mine warfare, anti-submarine warfare, and surface combat. But that vision ran into early technical problems. Some vessels also suffered mechanical failures, especially in the propulsion system, reducing their speed below what had been planned.
The littoral combat ship mine warfare system has still not been tested in large-scale real operations under complex combat conditions.
As for the mine warfare package itself, the Pentagon’s Director of Operational Test and Evaluation concluded in its 2025 report that the operational effectiveness and suitability of littoral combat ships fitted with this package could not be judged, due to insufficient data on the performance of the detection and neutralisation systems. The report also identified clear problems in some core components. The influence sweep system, which mimics ship signatures, was classified as operationally unsuitable, with readiness no higher than 29 percent, far below the Navy’s minimum threshold. In addition, the airborne mine neutralisation system carried by the Seahawk helicopter, which is responsible for destroying detected mines, showed low reliability before entering service and a limited ability to deal with most mine types under real threat scenarios.
There is also a design constraint. Littoral combat ships are built from aluminium rather than wood and fibreglass like the Avenger, giving them a higher magnetic signature and preventing them from entering minefields directly without risking detonation. They therefore have to stay outside the threat zone and depend on unmanned platforms to carry out the mission. Those platforms, however, are limited by communication range and line-of-sight requirements with the mothership, narrowing their operational reach, especially in rough maritime conditions or over greater distances.
Three Ships Facing an Impossible Mission
In this context, a report by the Centre for Maritime Strategy, an American research centre focused on national security in the maritime domain, notes that these ships have struggled to perform their missions even under ideal testing conditions. Trials conducted off Southern California in clear waters without visual obstacles showed that the systems failed to achieve the required efficiency. That raises an obvious question: how will they perform in the murky waters of Hormuz if they are already making such mistakes in a nearly perfect test environment?
Yet the challenge is not limited to poor visibility. It extends to a layered threat environment surrounding the mine-clearing operation itself. Along Iran’s southern coast, mobile launch platforms for anti-ship missiles such as the Noor and Qader are deployed, with ranges of up to around 300 kilometres. These missiles, especially in their final phase, fly extremely low, only a few metres above the water, reducing reaction time and complicating radar detection. Iran also fields anti-ship ballistic missiles such as Khalij فارس, capable of striking moving targets with manoeuvring warheads.
On the surface, the Islamic Revolutionary Guard Corps relies on swarms of small fast boats exceeding 50 knots, attacking in groups to surround ships from multiple directions. Some of these boats are fitted with light missiles and machine guns, while others serve as explosive-laden suicide craft. US intelligence estimates indicate that Iran still retains around 90 percent of its small boats and mine-laying craft even after the first American strikes.
At the same time, Iran’s Ghadir-class submarines are capable of operating in shallow waters where they are difficult to detect using conventional anti-submarine systems designed for larger submarines in deeper water. In other words, the operating environment itself gives these platforms a tactical advantage.
This means littoral combat ships would not operate free of threat. They would require continuous air and naval cover throughout the mine-clearing mission. The Seahawk helicopter conducting laser scans would remain vulnerable to short-range surface-to-air missiles, while the unmanned surface vehicles towing sonar systems would operate within narrow lanes only two nautical miles wide and close to fortified Iranian islands.
Experts argue that the United States alone does not have enough assets to carry out strike missions, escort duties, and mine clearance at the same time.
Emma Salisbury, a researcher at the Foreign Policy Research Institute, argues that the United States, without allied support, does not possess sufficient assets to conduct strike operations, escort missions, and mine clearance simultaneously. That adds another constraint to the effectiveness of these operations. The US Navy has only three littoral combat ships equipped with the mine warfare package. Field trials also reveal further fragility in the operating system, because the failure of any single component can halt the entire mission. In one test, the recovery mechanism for an unmanned surface vehicle malfunctioned, forcing another ship to retrieve it. The mothership itself could not do so because its aluminium design prevents it from entering the minefield without exposing itself to direct danger.
Opening the Strait Is Not the Same as Keeping It Open
None of this entirely rules out an American ability to open a passage through the strait. But the more pressing question is whether it could keep that passage open. As noted earlier, Iran can relaid mines faster than they can be removed. In a corridor only a few miles wide, a single mine, or even the suspicion of one, is enough to shut down an area that may have taken weeks to secure.
That means the Strait of Hormuz is, in essence, not simply a test of whether a passage can be opened once. It is a test of endurance and the capacity to sustain combat over a longer period. Success in such an environment will not be measured by a limited breakthrough that battlefield developments can quickly reverse.
