Understand Operation Praying Mantis and the roots of naval tension between Washington and Tehran

The Persian Gulf remains one of the planet’s biggest geopolitical and economic bottlenecks, where the transit of fossil energy often clashes with territorial disputes and shows of force. On April 18, 1988, this waterway was the scene of Operation Praying Mantis, the largest surface combat operation conducted by the United States Navy since World War II. The American offensive was a direct retaliation for the use of Iranian sea mines in international waters, which nearly sank the frigate USS Samuel B. Roberts four days earlier. To understand the diplomatic impasse that currently blocks Middle Eastern routes, remember the largest naval conflict between the US and Iran in the 1980s and the military lessons for the current war, an episode that permanently redefined combat tactics at sea.

The oil tanker war and the militarization of trade routes

The genesis of Operation Praying Mantis lies in the long and bloody aftermath of the Iran-Iraq War (1980-1988). From 1984 onwards, both countries began the so-called “Oil Tanker War”, attacking merchant ships from third countries to asphyxiate the enemy economy. Iraq focused on vessels leaving Iranian terminals, while Tehran targeted ships from Arab nations that financed Baghdad, such as Kuwait.

Faced with the imminent risk of a collapse in global oil supplies, Kuwait requested international protection. The United States responded with Operation Earnest Will, rechristening Kuwaiti tankers with the American flag and providing military escorts beginning in 1987. The Iranian response consisted of adopting asymmetric warfare:

• Indiscriminate spreading of M-08 type naval mines in international waters;
• Use of armed speedboats (Boghammar) for surprise attacks against unprotected ships;
• Transformation of oil platforms, such as Sirri and Sassan, into advanced command, control and military intelligence posts.

The breaking point occurred on April 14, 1988, when the USS Samuel B. Roberts collided with one of these mines, suffering severe structural damage and leaving dozens of sailors injured, with no fatalities. The recovery of intact mines with Iranian serial numbers provided Washington with the material evidence needed to justify punitive action.

The clash of forces in the gulf and the collapse of the conventional fleet

The Pentagon designed Operation Praying Mantis with the aim of imposing an unsustainable cost on the Iranian military infrastructure, structuring the fleet into Surface Action Groups (SAG). The order was to neutralize the Sirri and Sassan platforms and sink Iranian warships that tried to intervene.

American forces had destroyers, frigates, cruisers and air support from the aircraft carrier USS Enterprise. On the other side, the Iranian Navy tried to resist using its British-made patrol ships and frigates, left over from the pre-Islamic Revolution period. The tactical development highlighted the abysmal technological disparity:

Intelligence platforms: American troops invaded Sassan, captured military documents and destroyed it with explosives. The Sirri installation was neutralized by naval fire shortly thereafter;

Sinking of Joshan: The Iranian fast attack ship Joshan attempted to engage the Americans by firing a Harpoon missile. The projectile was evaded by US electronic countermeasures, which retaliated with Standard missiles, sinking the vessel;

Larger Fleet Destruction: The Iranian frigate Sahand, while trying to attack American aircraft, was hit by Harpoon missiles, laser-guided bombs and cluster bombs, sinking hours later. The frigate Sabalan was also badly hit and crippled.

By nightfall, Iran had lost half of its operational surface fleet. The event accelerated Tehran’s decision to accept, months later, UN Resolution 598, ending the war with Iraq.

The shift to asymmetric warfare and contemporary tactics

The impact of 1988 transcends military history. The technological massacre suffered in the Persian Gulf proved to Iran that it was impossible to confront US maritime hegemony in a conventional battle of brute force. This realization founded the naval doctrine that the Islamic Revolutionary Guard Corps (IRGC) applies today and exports to its regional allies, such as the Houthi rebels in Yemen.

Modern doctrine has abandoned large surface ships, considered easy targets for Western aviation and radar. In its place, Tehran has developed a defense ecosystem focused on area denial (A2/AD):

1. Mass production of ultra-fast speedboats capable of carrying out swarming attacks against larger vessels;
2. Development of a vast arsenal of anti-ship cruise missiles and suicide drones launched from land-based mobile platforms;
3. Outsourcing of military attrition to paramilitary groups financed by the regime, hiding direct State authorship and avoiding direct retaliation such as that which occurred in April 1988.

This is the exact model used to threaten the Red Sea, Strait of Hormuz and Gulf of Aden routes today, posing to Western naval coalitions the challenge of intercepting cheap technologies using multimillion-dollar defense missiles.

International law and the verdict of the Hague court

After the dust settled in the Persian Gulf, the conflict moved to the corridors of diplomatic justice. In 1992, Iran filed a case against the United States at the International Court of Justice (ICJ) in The Hague, demanding reparations for the destruction of its three oil platforms (including the 1987 Operation Nimble Archer case).

The Iranian foundation was anchored in the 1955 Treaty of Friendship, signed during the time of Shah Reza Pahlavi. Washington’s lawyers argued that the actions were a legitimate exercise of self-defense under Article 51 of the United Nations Charter.

The Court’s final decision, handed down in 2003, created a landmark in international maritime law:

• The ICJ ruled that the American attacks could not be justified as strict “self-defense” in the eyes of international law, as the actions did not irrefutably meet the requirement of immediate necessity and proportionality to protect the commercial fleet;
• Simultaneously, the Court rejected Iran’s request for billion-dollar compensation, arguing that the platforms had already had their commercial functions suspended by the war and were, in fact, integrated into the Iranian war machine.

The trial signaled a legal divide over the limits of armed response to indirect provocations in international waters, a precedent extensively studied by the UN in recent decades of military interventions.

The legacy of Operation Praying Mantis resonates directly with the strategic hesitation and diplomatic chess that permeates global navigation today. Current tensions in the Middle East operate under the shadow of this conflict, where Western powers avoid overt attacks on infrastructure on Iranian soil, seeking to manage low-intensity crises without triggering an all-out open war. The conversion of commercial fleets into armed battlefields remains a constant, proving that the waters of the Gulf will continue to be the ballistic bellwether of a region incapable of achieving permanent stability.