Can Iran Block the Strait of Hormuz by Military Power?

Reading into the military capabilities of Iran in the Arabian Gulf area

Image: AP

The current situation

The Strait of Hormuz is one of the most important naval choke points for oil trade in the world. According to the US Energy Information Administration (EIA), 18.5 million barrels of oil passed through this strait in 2018. This amount of oil constitutes 19% of the global demand for oil in that same year. Throughout the world, there are eight strategic passages for oil trade. The following table shows their importance:

NoName of the straitAmount of oil passingPercentage of oil passing
1Strait of Hormuz18.5 Mill. oil barrels19 %
2Malka Strait16 Mill. oil barrels16 %
3Cape of Good Hope5.8 Mill. oil barrels6 %
4Sues Channel5.5 Mill. oil barrels6 %
5Bab-el-Mandeb Strait4.8 Mill. oil barrels5 %
6Denmark Strait2.4 Mill. oil barrels3 %
7Bosporus Strait in Turkey2.3 Mill. oil barrels2 %
8Panama Channel0.9 Mill. oil barrels1 %

The geographical position of the Strait of Hormuz

Geographically speaking, the Strait of Hormuz – as shown in the photo below – is a narrow sea passage located between Iran and the Sultanate of Oman. The entry and exit passages range between 40-50 kilometers wide. The Strait is divided into two lanes, one for entry and the other for departure. Both lanes secured by two separated lanes.

Generally, each lane is 10-kilometer wide, suited for huge oil tankers. The tankers usually have to pass two small islands, “Small Tunb” and “grand Tunb”. both disputed territory by UAE and Iran.

Huge and heavy oil tankers usually ship in deep water for passing the strait. Therefore, blocking it could in consequence cause a possible military confrontation.

As for for possible military actions and in consequence the closure of the Strait of Hormuz, the following key questions come to mind:

What are the military means Iran can use for closing this strait in case the decision is made?

How can such a strait be closed from a military perspective?

For how long can it be closed?

Iran’s potentials in the Strait of Hormuz

After the war between Iran and Iraq, the military and navy forces went through a turning point when Iran changed its military doctrine from a classical power into a disorganized one. Most of the post-war era in the region was influenced by sanctions imposed by the US. These sanctions aborted any attempt to re-building military and navy capabilities. Additionally, the clashes between Iran and the US, which took place in 1988, forced Iran not to build up formal navy forces and prefer disorganized marine forces. During those clashes, the classical navy forces of Iran could not compete with the huge navy power by the US.

With the end this Operation, the US Air Forces destroyed many marine and intelligence installations located on two oil installations. As a consequence, three fast Iranian jet boats, one frigate, two fighter boats and the famous Iranian frigate Sablan were drowned by US navy and air forces. According to US sources, Iran lost half of its operational fleet in this confrontation, 55 Iranian marines were killed. Currently, Iran has only got disorganized navy forces in the Gulf.

Marine mines  

Although Iranian media have always covered all trainings of Iran’s military and Islamic Republican Guard Corps IRGC in the Arabian Gulf, it has always been noted that most of the power was limited to small boats or few frigates with land-to-sea missiles. However, US and British evaluations of Iranian naval forces have always showed concern with regard to marine mines used by Iran in the Gulf. Some international reports stated that Iran has got more than five thousand types of marine mines. It is true that these mines are not sophisticated, but they remain a serious threat to navigation as they cover a large area of the Arabian Gulf and could threaten the security of the Strait of Hormuz.  

Iran is widely believed to have used marine mines in recent attacks on oil facilities on the naval territory of the United Arab Emirates. This belief is becoming more certain every other day as international reports denote.

Below is a photo of an Iranian marine mine laid by Houthi militias opposite the coast of the Red Sea. Yemeni coast guards discovered tens of these mines and exploded them.

Photo of Sputnik

Fast Torpedoes

Despite the deployment of the US Fifth Fleet together with international forces in the Gulf, US military officials consider that safe sweeping of Iranian dangerous mines is a very complicated process with the presence of Iran’s go-fast boats that are used by IRGC in the water of the Arabian Gulf.  

Some estimations refer that Iran has got about 20 Chinese go-fast boats that are equipped with anti-shipping missiles. Iran’s fleet also has about 40 Swedish military boats and an unquantified number of small Iran-made ships. US forces have recently spotted cruise and ballistic missiles installed on bord of small IRGC ships.

Iran’s go-fast boats


Following the collapse of the Soviet Union, Iran bought three Russian “Class Kelo” Submarines, which constitute a real threat according to US military estimations. North Korea owns similar submarines and one of them drowned a South Korean ship eight years ago. As for Iran-made submarines, they are considered to be small ones made for purposes of reconnaissance and suicide attacks. These boats have been designed and developed by Malek Al Ashtar University of IRGC in Shahin Shahir in the province of Esfahan.

A photo of an Iranian Submarine

Anti-ship missiles

Iran has got three types of Chinese anti-ship missiles. During the last few years, Iran said that it produced other more sophisticated anti-ship missiles. However, Western sources state that Iran is only in possession of these three Chinese types of missiles:

  • SSC anti-ship missiles, named “Silk Worm”, have been used by Iran during its war with Iraq. These missiles have a range of 300 km. The photo below shows this Silk Worm missile during training of Iran Marines in the Arabian Gulf. 
SSC Missiles

There are other types of Chinese missiles used by Iran, like the C 801 and C 802. The Hezbollah in Lebanon used one of these missiles to target one of Israeli ships in the Mediterranean during the 2006 war between Israel and Hezbollah.

Firing a Chinese Silk Worm missile C 802

Iran-made Marine Rockets

  • Kader Rocket

Iran manufactured a copy of the Chinese Silk Worm anti-ship rocket by dismantling this rocket and manufacturing its small parts. This type of rockets, which is six-meter long, can be fired by ships. It weighs about 164 kg with a 360 pound explosive head. It has a range of 200 km with a speed that can reach up to 250 meter per second.  

Specifications of Kader Rocket.
  • Fateh Rocket

It is a land-to-land rocket with a range of 200 km, Iran has developed a marine version of this rocket. According to US experts, these rockets can target ships sailing in the Arabian Gulf.

Iran-made Fateh-110 rocket


How can Iran close the Strait of Hormuz?

Closing the Strait of Hormuz by military force means the closure of the most important artery of oil trade in the world. It also means that most Gulf States will be disconnected economically from the rest of the world. Undoubtedly, closure would be an endeavor, entailing a wide furious international reaction. In this respect, the US Congress Study Center published a study in 2012 on the possibility of closing the Strait of Hormuz by military force. The study attempted to answer this big question as to whether Iran could be able to close this vital naval road by military force or not.

It concluded as follows: Yes, Iran could close the Strait of Hormuz by military force, but this would be a gradual process, to avoiding any absorb and containing any potential military reaction by the international community.

According to CSC, a gradual closure of the Strait of Hormuz could be conducted by the following steps:

  • The declaration on oil shipment ban in the Strait of Hormuz;
  • The declaration of the possibility of stopping ships and checking their loads;
  • Using military capabilities to issue warnings to commercial ships and oil tankers in the area;
  • Using military power to target specific ships;
  • Deployment of marine mines in the Arabian Gulf and the whole area around;
  • Using submarines and anti-ship missiles to target military fleet and commercial ships.

Although it seems impossible to review the above steps, Iran already made these steps during the war with Iraq: it used the Chinese Silk Worm rockets to target oil tankers, and it deployed marine mines. One of these mines hit an American ship named “Samuel Band” at that time and consequently the US got involved in a direct confrontation with Iran as we mentioned above.

At that time, preliminary measures taken by Iran didn’t lead to the closure of the Strait of Hormuz, but they led to imposing higher taxes for ship insurances passing through such a dangerous area. These measures caused ships to stand in long queue to leave the Arabian Gulf. This was very costly for international trade, especially the prices of oil worldwide.

This study represents the viewpoints of the writer, and it doesn’t represent the viewpoints of Middle East and North Africa Media Monitor

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