A global choke point where just a few mines suffice
We know that the Strait of Hormuz is a vital node in the nervous system of the global economy: every day between 17 and 20 million barrels of oil pass through it (or rather: “used to pass”), about 20% of the world’s consumption, along with a significant share of liquefied natural gas and steady flows of fertilizers, foodstuffs, and industrial products.
Its vulnerability depends not only on geography – navigation corridors as narrow as 39 km, heavy traffic, and limited depths down to hydrographic minima of just 60 meters – but also on the fact that it is an ideal environment for mine warfare. In such a context, it is not necessary to scatter thousands of devices: even a few dozen can create a strategic effect, because the perceived risk is enough to block or slow commercial traffic.
This is the core of the Iranian doctrine: turning a relatively inexpensive weapon into a multiplier of global instability.
How to close a strait without truly closing it
Completely blocking the Strait of Hormuz is a complex operation even for an actor like Iran. The naval and air superiority of the United States and Israel would make maintaining a total interdiction difficult over the long term. However, the Iranian strategy does not necessarily aim at an absolute blockade, but rather at a “credible interdiction.”
Deploying mines, even in limited quantities, can have immediate effects. Just a few incidents – a damaged tanker, a hit cargo ship – can generate a domino effect. Insurance companies drastically raise premiums, companies can no longer afford them, some routes are suspended, crossing times lengthen due to security procedures. Traffic slows, costs rise, and the market reacts. It reacts… “badly.”
In 1988, during the so-called “Tanker War,” a single Iranian mine severely damaged the American frigate USS Samuel B. Roberts. Minimal material damage, immense reputational damage to the invincibility of the United States. The episode demonstrated how even a limited number of devices can have a disproportionate strategic impact.
Today, with much heavier and interconnected traffic, the effects would be amplified. A prolonged, even partial, disruption of oil and gas flow through Hormuz quickly translates into higher energy prices, with repercussions on inflation, food security, and political stability in numerous importing countries.
The Iranian arsenal: not quantity, but variety and sophistication
Iran possesses thousands of naval mines and, above all, an extremely diversified range. It is not a homogeneous system, but a layered arsenal combining technologies from different eras, from contact mines to advanced influence systems.
The simplest mines remain the contact type already deployed during the First World War and which played a key role in naval conflict during the Second World War: metal spheres anchored to the seabed by a cable, equipped with sensitive “horns” that detonate upon contact with the hull. Inside, there is an air bubble that ensures their buoyancy, and they can be placed on the water or hidden – remaining practically invisible – just a few centimeters below the water surface. Before the Normandy landing, the Germans placed them atop stakes driven into shallow waters off the French coast to explode when struck by an Allied landing craft. They are cheap, easy to produce, and still effective against unprotected commercial ships.
But the real qualitative leap is represented by influence mines, today the heart of the threat. These devices do not need to be struck: they “sense” the ship. They use sensors that detect environmental changes caused by the passage of a vessel, such as distortion of the Earth’s magnetic field produced by the steel hull, the noise of propellers and engines, or the water pressure variation generated by the ship’s displacement.
The combination of multiple sensors is what makes these mines particularly insidious. Some models require the coincidence of two or three signals – for example, magnetic and acoustic – before activating, reducing false alarms and allowing selection of specific targets, such as tankers or large military ships.
Added to this is a fully programmable internal logic: some mines can ignore the first ships passing and activate only on subsequent targets, or activate only after a certain time interval, rendering preliminary clearance attempts ineffective.
Maham, rocket mines, and hybrid systems: complete anatomy of the Iranian arsenal
Delving into the details of the Iranian arsenal reveals a much more complex picture than the simple distinction between “simple” and “advanced” mines suggests. Tehran’s strength lies not only in numbers – estimated between 2,000 and 6,000 devices – but in the combination of different systems designed to operate together, saturate the maritime environment, and make clearance extremely complex.
The most basic level is represented by the Maham-1 family, a traditional anchored mine equipped with electric contact sensors. It is the evolution of classic “horn” mines: when the hull strikes one of these sensors, the circuit closes and triggers the explosion. Simplicity should not be misleading. With a charge that in most variants reaches 120 kg of explosives – and in some cases drops to 20 kg for lighter versions – these mines remain extremely dangerous, especially in congested waters where accidental impact is more likely.
The qualitative leap occurs with the Maham-3, which represents the main threat in deep waters. It is an anchored but “intelligent” mine: once released, it does not remain on the seabed but rises along the anchor cable to position itself just below the waterline of passing ships. In this optimal position, it uses low-frequency acoustic sensors to identify the sound signature of vessels. Some versions can integrate directional sensors capable of discriminating the signal’s origin, and magnetic fuses designed also to detect submarines. With a total weight of about 383 kg and a charge of 120 kg, it can explode a few meters from the hull, causing devastating damage without direct contact.
Even more insidious is the Maham-2, a bottom mine designed to operate on the seabed. Unlike anchored mines, it is not visible in the water column and can be hidden by sediments, making sonar detection difficult. Its strength lies in the combination of magnetic and acoustic sensors, allowing it to “sense” a ship passing overhead. The charge, about 320 kg, is significantly more powerful than the anchored versions. But what makes it truly dangerous is its activation logic: it can be programmed with a delay of days and equipped with a target counter, ignoring the first ships to strike subsequent ones. This renders many preventive clearance techniques ineffective and turns every passage into a potential trap.
A more sophisticated variant of bottom mine is the Maham-6, derived from the Italian Manta model. Its conical shape is no accident: it reduces sonar signature and makes it difficult to distinguish from the seabed. In this particular use, it can easily be confused with one of the many debris scattered on the seabed of such trafficked waters. Again, it is an influence mine, but with a smaller charge, about 120 kg, which limits its use to relatively shallow depths, just like those at the elbow of the Strait of Hormuz, where the seabed rises to as little as 60 meters from the surface. In return, it offers high concealment and a greater chance of surviving clearance operations.
Alongside these static mines, Iran also has dynamic systems. Among these is a self-propelled mine, probably derived from the Chinese EM-56 model, which combines the characteristics of a bottom mine with a propulsion unit similar to a torpedo. This type of weapon can be launched from submarines or coastal platforms and reach a preset position before activating. Its estimated range between 10 and 20 kilometers allows mining areas without direct exposure to the enemy, increasing the system’s operational depth.
The most advanced level is represented by rocket mines, such as the Chinese-origin EM-52, reportedly in Iran’s possession. These mines position themselves on the seabed and, once detecting a ship’s passage, release a projectile that rapidly moves upward, striking the hull from below. This weapon system – a fully automated torpedo launcher – allows engagement of targets even at great depths, up to 200 meters or more, overcoming one of the traditional limits of bottom mines.
There are also very simple and inexpensive drifting mines, which float freely following currents and wind. Although formally banned by international conventions, they remain difficult to track and particularly unpredictable. Once released, no one, not even those who placed them, can know where they ended up.
Finally, “limpet” mines, applied directly to the hull by underwater operators or drones, represent a more targeted and extremely economical threat, usable in clandestine operations against single ships. They are practically equivalent to a large waterproofed hand grenade, equipped with a timer and magnetic contact to adhere to the hull. The more sophisticated versions have a shaped charge oriented inward to maximize the explosion’s effect and programmable sensors to detonate upon reaching a certain condition. For example, when they detect through hull vibration that the engines are at full power or, conversely, that the ship is slowly maneuvering in port.
Lastly, there are indications of the use of unconventional deployment systems, such as artillery rockets to scatter mines in shallow waters. This approach allows rapid and large-scale dispersion, particularly suited to scenarios like the Strait of Hormuz, where shallow depth amplifies the effectiveness of these devices.
The overall result is a layered arsenal covering the entire water column: contact mines to saturate, influence mines to select, bottom mines to hide, rocket mines to strike deep, and self-propelled systems to extend the range. It is not the single mine that makes the difference, but the deadly ecosystem they create when employed together.
Deploying mines is easy, removing them is a war
One reason mines are so effective is the cost-to-impact ratio. Laying a minefield requires limited resources: small motorboats, fishing vessels, or fast craft can disperse devices quickly and with difficulty to trace.
Clearance, on the other hand, is slow, risky, and technically complex. Mine removal operations require a precise sequence: detection via high-resolution sonar, contact classification, visual identification with underwater vehicles, and finally neutralization, often with controlled explosive charges.
Western navies today use advanced systems, including underwater drones, autonomous vehicles, and devices like remotely controlled torpedoes to destroy mines. However, even with these technologies, clearing a limited area can take weeks.
The problem is worsened by the very nature of modern mines. Some are designed to evade sonar, others to activate only in the presence of specific “signatures” (able to distinguish a large transport ship from a fast military boat or a slow civilian fishing vessel), and others can remain inactive until detecting a high-value target. Moreover, the possibility that new mines are laid during operations forces continuous surveillance.
In this context, clearance is never definitive: it is a dynamic process that must be accompanied by offensive operations to neutralize Iranian laying capabilities.
From the strait to conflict: scenarios and limits of the strategy
The systematic use of mines in the Strait of Hormuz represents a form of economic warfare even before military. It is not necessary to sink dozens of ships: it suffices to make the strait unsafe to hit energy markets, destabilize supply chains, and generate political pressure globally.
In the short term, a mining campaign would lead to an immediate rise in oil and gas prices, with cascading effects on inflation and food security. In the medium term, it would force the United States and Gulf countries into direct intervention to guarantee freedom of navigation, expanding the conflict.
But naval warfare history suggests a structural limit. Mines can block, slow, destabilize. They can inflict significant damage and force the adversary to react. However, they rarely alone determine a definitive strategic outcome.
In the Iranian case, their use appears consistent with a broader strategy: buying time, increasing costs for the adversary, and turning Western military superiority into a political and economic problem.
It is a logic already seen in war history: not to win by destroying the enemy, but to make the conflict too costly to sustain.
And in a strait only 39 kilometers wide, this logic can be enough to destabilize the balance of an entire planetary economy.
