Assessing the threat of Iran's drone carriers

Between late December and early January, reports surfaced that Iran’s Islamic Revolutionary Guard Corps Navy (IRGCN) is converting two merchant container ships owned by the sanctioned state shipping line IRISL Group into its first aircraft carriers, called the Shahid Mahdavi and Shahid Bagheri. The Iran Shipbuilding & Offshore Industries Complex Company (ISOICO) at Bandar Abbas near the Strait of Hormuz — the world’s main maritime oil transit chokepoint — is supporting the conversion. The IRGCN has been working on the Shahid Mahdavi since at least May and is expected to complete and commission it in 2023.

For now, Iran’s drone carriers are unlikely to pose a clear and present danger to the United States. Alongside other conventional capabilities, the U.S. possesses superior aircraft carriers, which, while ostensibly vulnerable to Iranian torpedoes and missiles, are safeguarded by a system of protective vessels, ultrasonic sensors, electronic countermeasures, and kinetic interceptors that surround each carrier in a battlegroup. Comparatively, and in all probability, Iran’s carriers are not strategic or tactical game changers, and they are overmatched strategically and operationally. Like the Iranian Navy’s other warships, they may confront capability-based constraints with launch and recovery as well as at-sea maintenance and repair operations. The Iranian carriers may also lack the anti-ship and air defenses required to resist attacks and survive direct engagement.

However, the drone carriers possess symbolic significance as a potential tool to defy U.S. initiatives in the Middle East and respond to Israel’s attacks against Iran. They also contain an asymmetric and opportunistic value in the form of selective strikes on the maritime assets and soft targets of Israel and other U.S. allies and partners in the region. According to Iranian media, the carriers will increase Iran’s long-range surveillance and strike capabilities in the Middle East and beyond.

Capability and conversion

The Shahid Mahdavi and Shahid Bagheri are being designed to carry helicopters and runway-launched, fixed-wing drones. The latter include the Shahed-136 explosive-tipped kamikaze drone with a range of up to 2,500 kilometers; Russia has employed these in the war in Ukraine, mainly against critical infrastructure targets, with devastating localized effects. Iran has also allegedly used them in several attacks on Israeli-linked tankers in the Persian Gulf. On Nov. 15, 2022, a Shahed-136 damaged the hull of the Israeli-controlled Eastern Pacific Shipping company’s oil tanker, the Pacific Zircon, 150 miles off the coast of Oman, with no reported spillage of cargo or injuries among the crew. On July 30, 2021, Iranian kamikaze drones struck the Israeli-operated petroleum product tanker M/T Mercer Street, also near Oman, killing two crew members, of British and Romanian nationality. These and other drone attacks on tankers are a new phase of the “Tanker Wars,” wherein Iran targets commercial vessels associated with Israel and other adversaries in response to Western economic pressure, to bolster its deterrence posture, and to flex its muscle in the region and further afield.  

This is not the first time Iran has repurposed and transformed into naval warships merchant vessels that were out of service due to economic sanctions. In 2020, the IRGCN converted a commercial ship into the multirole warship Shahid Roudaki for reconnaissance, combat, and logistics, with a potential operational range as far as the Red Sea, off the coasts of Saudi Arabia and Yemen. Like the Shahid Mahdavi and Shahid Bagheri, the warship takes its name from a martyr, assassinated Vice Admiral Abdullah Roudaki. It can carry helicopters, drones, and fast-attack, small-armed speedboats that the IRGCN has consistently used to surveil and harass U.S. naval vessels in the Persian Gulf. Some small-scale drones or quadcopters on the Shahid Roudaki were allegedly part of the Iranian strike on Saudi oil processing facilities at Abqaiq and Khurais in 2019, in conjunction with land-attack cruise missiles.

In 2021, the IRGCN converted an oil tanker into a forward base ship, the IRINS Makran, which can carry combat drones, among other capabilities. That year, the Makran deployed for four months in the Atlantic Ocean and Baltic Sea, where it represented Iran at a Russian naval parade and fleet review alongside the frigate IRINS Sahand. In December 2022, it was spotted transiting across the Pacific Ocean. Despite encountering setbacks in the past, the IRGCN is converting commercial vessels into naval warships to modernize its fleet. In the process, it intends to improve its maritime or seafaring capabilities and expand its operational range for the purpose of more effectively waging asymmetric warfare against adversaries in the Persian Gulf. 

Symbolism and opportunism

The Shahid Mahdavi and the Shahid Bagheri will presumably become part of the Iranian Navy’s drone carrier division, which comprises several ships and submarines that appeared at ceremonies and exercises exhibiting Iran’s sea-launched drone capabilities. As recently as Dec. 31, the Iranian Navy test-launched from the landing ship IRIS Lavan an Ababil kamikaze drone, which flew inland and struck a target appearing to be a mockup of Israel’s Eilat Naval Base.

Before that, on July 15, the Iranian Navy inaugurated the division by holding an official unveiling in the international waters of the Indian Ocean. During the ceremony, the division’s ships and submarines launched various surveillance, combat, and kamikaze drones. The event coincided with President Joe Biden’s first visit to the Middle East, including to Iran’s regional rival Saudi Arabia. Furthermore, in a show of defiance, the ceremony came after at least two drone attacks that Israel had allegedly conducted earlier in the year inside Iran to sabotage and set back its burgeoning unmanned aerial vehicle program. The latter is part of the four pillars of the Islamic Republic’s security strategy, alongside missiles, proxies, and cyberwarfare.      

Beyond symbolism, Iran’s ship-launched drone capability presents a viable, asymmetric and opportunistic threat to U.S. allies and partners inside and outside the region. As Iran did with its drones, it could export this capability to state and quasi- or non-state partners and proxies in the Middle East and around the world. It could also continue to use the capability against the oil tankers and facilities of Israel, Saudi Arabia, and other rivals. Iran could deploy its carriers, other military vessels, and repurposed commercial ships to carry out attacks, making them difficult to prevent beforehand and attribute afterward. This threat has pushed the United States, Israel, and Gulf Arab states like the United Arab Emirates and Bahrain to cooperate within the framework of the Abraham Accords on shared air defense systems — although defending against incoming drones remains a serious technical challenge.

Iran’s sea-launched drone capability provides Iran with strategic depth, greater strike options, and the means to threaten adversaries from the Gulf of Aden to the Gulf of Oman. It may influence shipping patterns across the Arabian Sea and into the Indian Ocean, potentially threatening the Sea Lines of Communication (SLOC) of its adversaries when they are out to sea and more vulnerable. The introduction of Western intercept capabilities and integrated air-defense systems partially mitigated the effectiveness of Iranian-supplied drones in Ukraine. However, when it comes to the Persian Gulf and Indian Ocean, the vastness of the area of operation combined with the resource constraints of the U.S. and the despondency and resilience of Iran limit the ability to blunt this emerging capability.

When deployed later this year, Iran’s drone carriers will threaten shipping vessels and other high-value targets across the region and beyond. The higher priorities of the U.S. Navy outside the Middle East, coupled with the nature of asymmetric capabilities, create openings for regional opportunists like Iran to strengthen deterrence, project power, generate instability, and further threaten shipping channels. Notably, after conducting a series of naval and army-related drills in January, the Islamic Republic articulated that its modified military doctrine would focus on deploying offensive drone and missile technology to destabilize the Persian Gulf if confronted with a larger conflict.

Conclusion

As in the past, Iran is converting sanctioned and unused commercial vessels into naval warships. This year, it plans to complete and commission at least one of two drone carriers to add to its pre-existing division that was on full display last summer. Despite the strategic and operational advantages that the U.S. may possess, the Iranian carriers could symbolically deny American initiatives in the region, not to mention counteract Israeli attacks against the Islamic Republic.

Ship-launched drone strikes could also allow Iran to continue targeting the tankers and other assets of its adversaries as well as escalate conflicts with them at longer ranges inside and outside the Persian Gulf and Indian Ocean. Unlike in Ukraine, this threat is exacerbated by the exceeding difficulty of the United States and its regional allies and partners to deploy integrated air defenses in the vast expanse of a maritime region vulnerable to Iranian kamikaze drones with a strike radius of 2,500 km. The resource limitations and competing priorities of the U.S. Fifth Fleet, and U.S. Navy more generally, further compound the threat.

As with Russian drone and missile attacks in Ukraine, Iran uses its drone capability for influence and advantage. Since the expiration of the United Nations arms embargo against Iran in October 2020, it has exported drones to countries like Venezuela, inaugurated a drone factory in Tajikistan, and, more recently, reportedly opened several such production plants in Russia. With increased drone manufacturing at multiple overseas locations, the acquisition and application of advanced technologies for surveillance and combat, and the imminent threat of drone carriers in regional and international waters, a picture emerges of an effective and expansive Iranian drone program. It is supported by the full weight of the state and influenced by key defense-sector organizations, such as the IRGC Aerospace Force Research and Self-Sufficiency Jihad. Considering the challenges of containing this program, regional actors like Saudi Arabia could contemplate following in the footsteps of the United Arab Emirates and holding maritime security talks with Iran, as a potential first step to a more comprehensive regional security framework.  

Eric Lob is a non-resident scholar with the Middle East Institute’s Iran Program and an associate professor of politics and international relations at Florida International University.

U.S. Army Col. (ret.) Edward Riehle works on advanced technologies, sensors, and sensor processing in Northern California.

Photo by Morteza Nikoubazl/NurPhoto via Getty Images