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Iran views its external security as reliant on its ability to exert influence in the Middle East. Owing to Tehran’s relative diplomatic and economic isolation, military power is the main tool available to Iran’s leaders for attaining this objective. To be effective, however, Iran must be able to use its military capabilities to credibly threaten its neighbors, to control or limit access to key chokepoints in the Persian Gulf, and to deter a direct attack against Iran or its forces.
Iran cannot achieve these ends with its arsenal of main battle tanks, capital ships, and fighter aircraft—the traditional mainstays of land, sea, and air power—which are aging and obsolete. As a result, Iran’s leadership has invested heavily in unconventional capabilities such as its nuclear program (which until at least late 2003 had an active military component), proxy networks in regional countries, and emerging cyber warfare technologies.
Iran has also expanded its asymmetric use of conventional military capabilities, which now comprise a key part of Iran’s overall security strategy. This asymmetric strategy has taken the form of attacks, usually carried out by Iran’s Islamic Revolutionary Guard Corps (IRGC) or by Iran’s proxies in the region, which employ relatively inexpensive but difficult-to-counter weapons and are calibrated not to provoke large-scale military retaliation. The IRGC and its proxies simultaneously wield many of those same weapons in a defensive anti-access/area-denial capacity to deter any military response to their offensive strikes.
These conventional capabilities may broadly be separated into three categories: increasingly precise conventionally-armed missiles, unmanned aerial systems (known colloquially as drones), and naval capabilities including fast-attack craft, missile boats, and small submarines. This report reviews Iran’s capabilities in each category and their potential operational and strategic consequences.
Iran’s missile arsenal includes both ballistic and cruise missiles, as well as anti-ship variants of each. This report focuses on missiles that are most likely to be used in conventional combat: cruise missiles, anti-ship missiles, and ballistic missiles that have demonstrated a level of precision and accuracy suitable for effective battlefield employment when armed with non-nuclear warheads. The role of Iran’s missiles as potential nuclear weapon delivery systems is covered in a separate report.
Ballistic missiles fly on a parabolic arc from their launcher to their target. Iran has made substantial technological advances in ballistic missile accuracy and precision over the past decade. This has enabled Tehran to use its ballistic missile arsenal effectively in conventional combat, including in strikes on Islamic State (IS) and Kurdish separatists in Iraq and Syria in 2017 and 2018 as well as in an attack on Iraqi military bases hosting U.S. forces in January 2020. Iran’s proxy forces, in particular Yemen’s Houthi rebels, have also effectively used Iranian-designed ballistic missiles.
The missiles used in these strikes have largely been of the solid-fueled Fateh and liquid-fueled Qiam missile families. They possess ranges from 300 to 1,500 kilometers, enabling them to reach targets in Iraq, Israel, Syria, and the Persian Gulf states. Their recent performance has indicated a precision capability of between 10 and 100 meters Circular Error Probable (CEP), enabling them to reliably strike targets such as large buildings and airstrips.
U.S. Central Command estimated in 2020 that Iran possessed 2,500 to 3,000 ballistic missiles in total, including less-precise models. Iran’s surface-to-surface ballistic missiles are under the operational control of the Islamic Revolutionary Guard Corps (IRGC) Aerospace Force.
First tested in 2002, the Fateh-110 is the base model of the Fateh family of missiles. It is a steel-bodied, single-stage, solid-fueled missile capable of delivering a 500 kg payload up to 300 km. It and its variants are designed to be fired primarily from road-mobile launchers, of which Iran likely has at least one hundred deployed. According to a 2015 U.S. Air Force study, the Fateh-110 has a CEP of 100 meters, although Iran reportedly later developed a guidance kit that could reduce its CEP to 30 meters or less.
The Fateh-313, unveiled in 2015, is an improved variant of the Fateh-110 with a maximum range of 500 km. It features a smaller nose cone than the Fateh-110, and thus probably has a smaller payload. According to Iranian sources, components of the missile are made with carbon fiber, a composite material that is lighter than steel and allows for greater range. The Fateh-313 was likely used in Iran’s missile attack on U.S. forces in Iraq in January 2020. Expert analysis of that attack reported by The Economist suggests that some of the missiles used had a CEP as low as 10 meters.
The Zolfaghar is a single-stage, solid-fueled missile unveiled in 2016 with a maximum range of 700 km. It appears to be derived from the Fateh-313. Its exact payload and CEP are unknown, although Iranian media have estimated the Zolfaghar to be capable of delivering a payload of between 450 and 600 kg. The Zolfaghar was reportedly used in Iran’s 2017 strike against IS in Syria. Iran unveiled a variant of the Zolfaghar named Dezful with a claimed range of 1,000 km in 2019 and another variant named Haj Qasem with a claimed range of 1,400 km in 2020.
The Raad-500 was unveiled in February 2020. It is reportedly an improvement on the Fateh design with a 500 km range and a CEP of 30 meters. According to IRGC Aerospace Force commander Amir Ali Hajizadeh, its body is made entirely of a non-metallic composite material. The Kheibar Shekan, unveiled in February 2022, has a claimed range of 1,450 km. According to Hajizadeh, it is made from a light composite material and can be prepared for launch more quickly than similar missiles. Hajizadeh described it as having “pinpoint” accuracy but did not disclose a CEP. The Kheibar Shekan visually resembles other missiles in the Fateh family but has a slightly different warhead shape, possibly indicating design innovations that could set it apart as a new missile class.
Iran and its proxies have repeatedly used the liquid-fueled Qiam missile in conventional strikes. The Qiam-1, unveiled in 2010, is a single-stage missile, derived from the Scud model, that is capable of delivering a 650 kg payload to a range of 800 km. The missile has a road-mobile launcher, but it is also designed to be launched from underground silos. Iran has claimed that the Qiam-1 features a maneuverable re-entry vehicle (MARV) and that its distinct design—featuring a triconic warhead and no tail fins—makes it difficult to detect with radar.
A 2016 report by The Washington Institute for Near East Policy estimated the Qiam-1 to have a CEP of several hundred meters; however, as it was one of the missiles reportedly used in the January 2020 strike on U.S. forces in Iraq, which was widely considered accurate, it is possible that the Qiam-1’s CEP has improved in recent years. Iran also reportedly employed the Qiam-1 in its strikes against Islamic State positions in 2017 and 2018.
Iran-backed Houthi rebels in Yemen have developed and used variants of the Qiam-1, likely with Iranian assistance. According to the U.S. Defense Intelligence Agency in 2019, the Houthis had used a variant named Burkan-2H to attack targets in Saudi Arabia from ranges of over 900 km. In January 2022, the Houthis claimed to have used a Qiam-1 variant named Zulfiqar in an attack on the United Arab Emirates, reportedly from a range of 1,350 km.
Source: 2019 Iran Military Power report, U.S. Defense Intelligence Agency.
Iran has equipped variants of the Fateh missile with guidance mechanisms known as terminal seekers. This makes the missiles more effective at hitting moving targets, namely ships. Iran’s anti-ship missiles (ASBMs), like its other ballistic missiles, have largely been under the operational control of the IRGC Aerospace Force. However, the IRGC Navy reportedly assumed control of ASBMs for the first time during military drills in December 2021.
Khalij Fars (Persian Gulf) and Zolfaghar Basir
The Khalij Fars is a Fateh-110 variant that entered service in 2014 with a maximum range of 300 km and a reported 650 kg payload. It is equipped with an electro-optical terminal seeker, which Iran claims is capable of striking targets in all light and weather conditions. According to Hajizadeh, the Khalij Fars has impacted to within 8.5 meters of its point of aim during testing; however, Iran has concealed the missile’s nose cone in its public displays, rendering independent analysis of its terminal seeking capability difficult. Iranian media has claimed that the Khalij Fars travels at up to three times the speed of sound and can reach its maximum range in less than five minutes.
In 2020, the IRGC Aerospace Force unveiled the Zolfaghar Basir, an anti-ship version of the Zolfaghar surface-to-surface ballistic missile. The Zolfaghar Basir has a claimed range of 700 km and, like the Khalij Fars, is equipped with an electro-optical terminal seeker.
The Hormuz-1 and Hormuz-2 are Fateh-110 variants with a 300 km maximum range and a reported payload of 500 kg. They are equipped with anti-radiation homing terminal seekers, making them function as radar-seeking missiles. They would therefore be unable to effectively target ships whose radars have been switched off. Iran has claimed that the missiles have struck a radar device mounted on a 20-foot shipping container during testing. Iranian media has reported that they can reach speeds of four to five times the speed of sound.Both missiles were unveiled in 2014, and there does not appear to be any substantial difference in capability between them.
Cruise missiles function essentially as pilotless aircraft. They are powered by an air-breathing jet engine and fly slower than ballistic missiles and on a flatter trajectory closer to the earth’s surface. Cruise missiles can be divided into two categories based on their intended target set: land-attack and anti-ship.
Land-Attack Cruise Missiles
Land-attack cruise missiles (LACMs) are meant to strike targets on the ground. Iran began developing LACMs in 2001, when it purchased several Soviet Kh-55 missiles on the Ukrainian black market. Iran’s cruise missiles made slow progress over the subsequent decade, due in part to Tehran’s difficulties in obtaining and producing the complex turbojet or turbofan engines used to propel them. Since 2012, however, Iran has unveiled, tested, and used in combat multiple LACM models. Iran’s current LACM arsenal can be broken down into three missile families: the Soumar, the Ya Ali, and the Quds.
The Soumar is a ground-launched missile with a maximum range of 700 km that was unveiled in 2015. It is derived from the Soviet Kh-55 (AS-15) cruise missile and is widely considered to be either an upgrade of or identical to the Meshkat missile unveiled in 2012. In February 2019, Iran displayed an improved variant of the Soumar named Hoveizeh, with a claimed range of 1,350 km.
The Soumar and its variants have substantial differences from the Kh-55, which is an air-launched missile with a range of 2,500 to 3,000 kilometers. The shorter range of the Soumar likely results from Iran’s inability to reproduce the advanced turbofan engine used in the Kh-55. Iran instead reportedly substituted it with a variant of the French Microturbo TRI 60-2 turbojet engine. The Hoveizeh’s claimed improvement in range over the Soumar may be due to Iran having recently obtained or produced a turbofan engine.
According to Iranian media, these missiles have a guidance system that relies primarily on a TERCOM system of pre-recorded contour maps as well as Glonass satellite positioning and an inertial navigation system (INS). Analysis of the missiles’ nose cones by independent researcher Shahryar Pasandideh suggests that they also have radar-based terminal guidance.
The Ya Ali has a maximum range of 700 km and was unveiled in 2014. According to Iran’s semi-official Tasnim News Agency, it is an air-launched missile; but the same source claims it has a solid-fuel rocket booster, which is generally associated with ground-launched missiles.
The Ya Ali is smaller than missiles in the Soumar family, and presumably carries a smaller payload. It is reportedly propelled by an Iranian variant of the French Microturbo TRI 60 turbojet engine, which is also used in the Soumar. The Ya Ali is possibly derived from the Chinese C-602 anti-ship cruise missile.
Saudi Arabia claimed that Ya Ali missiles were used in an attack by the Houthis on Abha Airport in June 2019 and also in the Iranian attack on Saudi oil infrastructure in September 2019. However, the United Nations panel convened to investigate the incidents concluded that the missiles used were in fact the Quds-1.
The Quds-1 has an estimated maximum range of 800 km. It was unveiled by the Houthis in July 2019 and has not been claimed by Iran as part of its arsenal. However, it is almost certainly Iranian-made: a U.N. expert panel concluded that the Quds-1 could not have been produced in Yemen; the Quds-1 contains components known to be possessed by Iran; and a model closely resembling the Quds-1 was displayed in a defense exhibition at Iran’s IRGC-run Imam Hossein University. The Quds-1 uses a Czech TJ100 turbojet engine and has a solid-fuel rocket booster, likely making it a ground-launched missile.
The Quds-1 was used in the September 2019 attack on Saudi oil infrastructure. Three of the seven cruise missiles used in that attack reportedly fell short of their intended targets. In late 2020, the Houthis reportedly claimed to have developed a Quds-2 version with an extended range of up to 1,000 km.
Anti-ship cruise missiles (ASCMs) are equipped with active radar seekers for use against ships. They may be fired from ships, aircraft, ground launchers, or submarines. ASCMs launched from land are sometimes referred to as coastal defense cruise missiles (CDCMs).
Iran first acquired ASCMs when it bought Silkworm missiles from China in 1987. In the decades since, it acquired and improved upon several other Chinese models. Iran’s ASCMs are largely under the operational control of its naval forces: as of 2019, more than 70 vessels equipped with ASCM launchers were distributed between the IRGC and regular navies. Iran also has land-based ASCM launchers that it can deploy on its coast or on islands it controls in the Persian Gulf. In 2019, Iran claimed to have successfully launched an ASCM from a submarine for the first time. All of Iran’s existing ASCMs travel at subsonic speeds, although Iran has claimed that it is developing a supersonic variant.
Iran’s ASCMs can be categorized based on the Chinese missile system they derive from: the C802 and C700 series, and the Silkworm.
The Noor missile is an Iranian-produced version of the C802 ASCM with a maximum range of 120 km. The Ghader and Ghadir are both Iranian improvements on the C802 design, with maximum ranges of 200 km and 300 km respectively. All three missiles are propelled by a turbojet engine and are reportedly equipped with radar and infrared guidance systems. Iran’s naval forces were estimated in 2019 to have nearly 30 vessels equipped with C802 missile family launchers. The long range of the Ghader and Ghadir compared with most ASCMs enables them to threaten most of the Persian Gulf even if launched from shore in mainland Iran.
The Kosar and the Nasr are Iranian versions of the short-range C700-series ASCMs. The Kosar is derived from the C701 and has a reported maximum range of 15-20 km. The Nasr is a C704 version with a 35 km maximum range. In 2012, Iran claimed to have produced an upgraded version of the Nasr with radar-evading and anti-jamming capabilities, called the Zafar. Both the Kosar and Nasr reportedly can be guided by radar and television signal and are propelled by a solid rocket booster. Iran had an estimated 46 vessels equipped with Kosar and Nasr launchers as of 2019, all of which are fast attack craft controlled by the IRGC Navy.
The Jask-2 is a submarine-launched ASCM derived from the Nasr. Iran claimed to have successfully tested it in February 2019. The Jask-2’s range and guidance system are unknown but are likely similar to the Nasr’s. One notable feature of the Jask-2 is its launch capsule, which is reportedly equipped with a motor that enables the capsule to maneuver underwater before surfacing and releasing the missile. It is designed to be fired from Iran’s Ghadir (Yono) class of midget submarines.
The Raad is an upgraded variant of the Silkworm missile that Iran imported from China in the late 1980s. It was introduced in 2004 and reportedly has a maximum range of 350 km. It is propelled by a turbojet engine and a solid rocket booster, and features an inertial navigation system (INS) in addition to a radar or infrared seeker. INS guidance could enable the Raad to strike targets inland as well as at sea. The Raad was successfully tested in 2007 and 2010 and has reportedly been in service for over a decade. It was designed to be both ground- and ship-launched, although it appears so far to rely mostly on land-based launchers. The Raad’s range nonetheless enables it to strike targets throughout the Persian Gulf even if launched from shore in mainland Iran.
In 2020, Iran unveiled the Abu Mahdi, an anti-ship version of the Hoveizeh cruise missile with a claimed range of 1,000 km. The Abu Mahdi’s substantially longer claimed range has led analysts at the International Institute for Strategic Studies (IISS) to question whether Iran possesses sufficiently-developed target acquisition or guidance capabilities to effectively operate the missile.
Source: 2019 Iran Military Power report, U.S. Defense Intelligence Agency.
Unmanned aerial systems (commonly known as unmanned aerial vehicles (UAVs) or drones) are remote-controlled pilotless aircraft. Drones generally perform two military missions: intelligence, surveillance, and reconnaissance (ISR) and striking targets using on-board munitions or explosive payloads. “Kamikaze” drones, which carry their explosive payload all the way to their target, function essentially as remote-controlled cruise missiles.
Iran’s long-range drones, like its missiles, are mostly controlled by the IRGC Aerospace Force; however, other branches of the regular army and IRGC operate drones in varying capacities. Iran has largely designed and produced its drones domestically since the Iran-Iraq War, although it relies on imports for certain components and may have benefitted from its capture in 2011 of a U.S. RQ-170 Sentinel drone that crash-landed in eastern Iran while operating in Afghanistan. Tehran has widely proliferated drones to its proxies and has reportedly trained those groups to both operate Iranian drones and manufacture their own.
Iran first used strike drones in its 2018 missile attack on IS in Syria, and did so again effectively in its September 2019 attack on Saudi oil infrastructure. Thereafter, drones became a regular component of strikes carried out by Iran and its proxies, including a lethal kamikaze drone attack on the Mercer Street, an oil tanker in the Arabian Sea, and a complex attack on a U.S. military outpost in Syria in 2021.
Iran and its regional proxies also now routinely use drones to surveil U.S. and other foreign assets. U.S. officials estimated in 2019 that Iran made two to three reconnaissance flights daily with drones over the Persian Gulf. In 2017 and 2019, U.S. forces brought down Iranian drones operating near their positions; Pakistan also reportedly downed an Iranian drone operating inside its airspace in 2017. Israel has shot down drones allegedly operated on its borders by Iran or Hezbollah on at least three occasions in 2018 and 2021.
Iran’s drones can be divided into three main families—Ababil, Shahed, and Mohajer—plus an assortment of other models.
The Ababil and its variants are the mainstays of Iran’s drone arsenal, with early versions dating from the late 1980s. The Ababil-2 is an ISR- and strike-capable drone first developed in the late 1990s. Iran claims that contemporary versions of the Ababil-2 have an operating range of 100 km, a flight ceiling of 3,350 meters, a top speed of 250 km per hour, and an endurance of up to 2 hours. The Ababil-3 is a dedicated ISR platform with a reported 100 km operating range, 5,000 meter flight ceiling, 200 km per hour top speed, and 4 hour endurance.
Iran has widely proliferated the Ababil to its proxies. U.S. officials have claimed that the Qasef-1, a kamikaze drone used by the Houthis to strike Saudi oil facilities, is a variant of the Ababil-2. Hamas has publicly displayed an Ababil drone, and Hezbollah is widely reported to possess the Ababil as well.
The Shahed-129 is an ISR- and strike-capable drone with an operating range of 1,700-2,000 km, a flight ceiling of 7,315 meters, and a 24-hour endurance. Iran first publicly announced production of the Shahed-129 in 2013 and claimed to have upgraded it in 2016 with a satellite communication datalink. The Shahed-129 is an operational system: Jane’s estimated Iran to have produced more than 50 Shahed-129s as of September 2019.
The Shahed-123 is a smaller version of the Shahed-129 that has not been publicly unveiled by Iran. It has reportedly been observed several times in Syria, however, and some Shahed-123s might be operated by the Syrian government. A crashed Shahed-123 was recovered by U.S. forces in Afghanistan in 2016. The U.S. Defense Intelligence Agency categorized the Shahed-123 as an ISR-dedicated drone in a 2019 report, but a United Nations panel identified a gyroscope matching the Shahed-123 from the wreckage of kamikaze drones used in Houthi-claimed attacks on Saudi oil infrastructure that year. It is therefore possible that armed variants of the Shahed-123 exist and that Iran has proliferated them to its proxies.
The Mohajer drone dates to the Iran-Iraq War. Of the models currently in service, the Mohajer-2, first introduced in the 1990s, is a reconnaissance drone with an operating range of only 50 km. The Mohajer-4, introduced in the early 2000s, is also an ISR-dedicated drone with a reported operating range of 150 km, a flight ceiling of 4,500 meters, a top speed of 180 km per hour, and an endurance of 5 hours. The Mohajer-6, unveiled in 2017, is an ISR- and strike-capable drone. Iran claims that the Mohajer-6 has a 2,000 km operating range and a 24-hour endurance; however, these claims had not been independently verified as of February 2022.
The Sadegh is an ISR- and strike-capable drone reportedly equipped with air-to-air missiles. According to Iranian media reports, it is likely an upgraded Mohajer-2 with a 200 km operating range, 4,500 meter flight ceiling, 200 km per hour top speed, and 6 hour endurance.
Hezbollah used Mohajer drone variants during its 2006 war with Israel and the Mohajer has been reported in combat use in Syria’s civil war. Venezuela also collaborated with Iran in 2013 to develop a Mohajer variant known as the Arpia-001.
The Karrar is an ISR- and kamikaze strike-capable drone first unveiled in 2010. Iran claims that its most recent version, the Karrar-3, has an operating range of 1,000 km, a flight ceiling of 10,670 meters, a top speed of 700 km per hour, and an endurance of 75 minutes. It reportedly can carry a single 250-kilogram payload. The Karrar functions essentially as a medium-range cruise missile that can carry out surveillance while on its way to its target.
The Fotros, unveiled in 2013, is a large ISR- and strike-capable drone with a reported 2,000 km operating range, 7,620 meter flight ceiling, and 16-30 hour endurance. These reported capabilities, if accurate, would make the Fotros similar to the Shahed-129.
The Raad-85, also unveiled in 2013, is a kamikaze drone with a reported range of 100 km. The Yasir is an ISR-dedicated drone that Iran purports to be a reverse-engineered version of the U.S. Scan Eagle, one of which Iran claimed to have captured in 2012 (a claim the United States denied). In 2015, the commander of Iran’s regular army Ground Forces said that the Yasir and “2 to 3 other types” of drones were converted to kamikaze drones and used in an exercise alongside the Raad-85.
Iran also attempted to reverse engineer the U.S. RQ-170 Sentinel that crash-landed in Iranian territory in 2011, resulting in the ISR- and strike-capable Saeqeh (IRN-170) drone. Multiple versions of the Saeqeh apparently exist, one of which was shot down by Israel in 2018 after crossing into Israeli airspace from Syria. However, there is no public evidence that the Saeqeh matches the RQ-170’s capabilities. Iran’s drone arsenal also contains several other models that broadly fall within the spectrum of capabilities outlined by the drones described above.
Source: 2019 Iran Military Power report, U.S. Defense Intelligence Agency.
The third pillar of Iran’s asymmetric military strategy is to use small naval vessels to limit access to the Persian Gulf and harass, obstruct, and—in the case of direct conflict—overwhelm U.S. and allied naval forces operating there. These vessels, mostly controlled by the IRGC Navy, are equipped to fire anti-ship cruise missiles, lay mines, or carry out swarm attacks with rockets and small arms.
IRGC Navy small craft have frequently harassed U.S. vessels in the Gulf: the U.S. Navy reported “unsafe and unprofessional” interactions with Iranian forces in the double digits annually between 2015 and 2017, followed by a two-year lull and then an uptick in 2021.
Iran’s naval capabilities can largely be divided into three categories: missile boats, fast inshore attack craft, and light submarines.
According to the U.S. Defense Intelligence Agency, as of 2019 the IRGC Navy maintained a force of roughly 50 fast-attack craft armed with anti-ship cruise missiles (ASCMs). Some are imported vessels that Iran acquired as early as the 1990s, whereas others are domestically-produced models based on foreign designs. In May 2020, for example, Iran’s Ministry of Defense and Armed Forces Logistics (MODAFL) announced that it had delivered 112 new vessels to the IRGC Navy, five of which appeared to be domestically-produced missile boats that upgraded earlier designs such as the Peykaap and Houdong.
Iran purchased ten Houdong (Thondor/Tondar) missile boats from China in the mid-1990s which continue to form the core of the IRGC Navy’s missile capabilities. Each Houdong is equipped with four ASCMs of the C802 family (which includes the Iranian-made Ghader and Ghadir variants), in theory allowing them to engage targets up to 300 kilometers away—enabling each Houdong to provide fire support over an area comprising roughly half of the Persian Gulf.
Iran received its first Houdongs in 1992, meaning that the vessels are now approaching 30 years in service and are possibly nearing the end of their service life.
Iran also possessed an estimated 25 Peykaap II missile boats as of 2019, which it domestically produces based on a North Korean design. Each Peykaap II is equipped with two Kosar (C701) or Nasr (C704) ASCMs. As those missiles have maximum ranges of 20 km and 35 km, respectively, the Peykaap II cannot project firepower over nearly as wide of an area as the Houdong. As of 2019, Iran also operated an estimated five Peykaap III missile boats, an upgraded version of the Peykaap II.
Iran’s fleet of missile boats also includes an estimated five C-14 (China Cat) and ten Mk 13 vessels, which Iran purchased from China in 2000 and 2006, respectively. Both types of vessel are reportedly armed with the 35-km range Nasr (C704) ASCM. In 2020, IRGC Navy commander Alireza Tangsiri announced that Iran was designing a larger missile-armed corvette called the Shahid Soleimani, which may be the IRGC Navy’s intended replacement for its ageing Houdongs. Iran has also put ASCM launchers on civilian vessels, notably during a two-week standoff in May 2019 in which U.S. Navy vessels in the Persian Gulf shadowed two Iranian merchant boats that had been loaded with missiles and launchers.
Fast Inshore Attack Craft
The IRGC Navy operates hundreds of fast inshore attack craft of various designs. Most are speedboats lightly armed with machine guns and multiple rocket launchers. A few models, including the Peykaap I and reportedly the Tarlan (of which Iran was estimated in 2019 to possess 15 each), are also armed with one or two torpedoes. These small craft are meant to operate in large groups that swarm and overwhelm a larger vessel.
Importantly, Iran has also configured some of its fast inshore attack craft to carry mines. According to the U.S. Defense Intelligence Agency, in 2019 Iran had a stockpile of more than 5,000 naval mines. Experts estimate that the types of mines in this arsenal range from century-old contact mines to “smart mines” modeled after Russian and Chinese designs that can detect a nearby ship and fire a guided torpedo at it. The IRGC Navy’s Ashoora-class fast inshore attack craft are configured to carry one or two mines at a time. Those or similar vessels may have been used by the IRGC Navy in limpet mine attacks on two oil tankers in the Persian Gulf in June 2019.
Larger ships and submarines operated by Iran’s regular navy can transport larger quantities of mines, and Iran could also lay mines using civilian vessels.
Iran has recently invested in small submarines that are well-suited for asymmetric warfare. Unlike its missile boats and fast inshore attack craft, Iran’s submarine force is operated by its regular navy, rather than the IRGC. All of Iran’s submarines are diesel-powered, although Iran has stated a desire to develop a nuclear-powered submarine.
The Ghadir is a domestically-produced midget submarine that is a copy of the North Korean Yono design. According to the Office of Naval Intelligence, Iran purchased at least one Yono from North Korea in 2004. As of 2019, Iran was estimated to possess 14 Yono/Ghadir-class submarines. The Yono displaces only 120 tons, making it easier to maneuver in the Persian Gulf than Iran’s Kilo-class submarines (4,000 tons). Each Yono-class submarine is armed with torpedoes, is capable of laying mines, and, Iran claims, can launch anti-ship cruise missiles.
In 2019, Iran commissioned one domestically-designed and -produced Fateh-class submarine. The Fateh reportedly displaces 600 tons, is armed with torpedoes, is capable of laying mines, and has test-fired a Jask-2 ASCM, apparently successfully. The commander of Iran’s regular navy has said that Iran plans to produce up to 20 Fateh-class submarines. Iran is also developing a new attack submarine named Besat. The Besat reportedly displaces 1,300 tons and is intended to be armed with torpedoes and ASCMs. None are known to have entered service.
Prior to 2002, and to a large extent until the mid-2010s, Iran’s ability to strike conventionally beyond its borders was limited to a Scud-based missile arsenal. Iran’s subsequent development of its conventional military capabilities has enabled it to carry out strikes that are more precisely targeted—and therefore more tactically and operationally effective. This increased operational potency has strategic implications. For Iran to achieve its goal of influencing its region through the threat of force, it needs to be able to inflict harm on its adversaries and to deter any large-scale military response that Tehran’s or its proxies’ threats or actions might elicit.
Iran has demonstrated its ability to debilitate, at least temporarily, important civilian and military infrastructure. The coordinated drone and cruise missile attack on Saudi Arabia’s Khurais and Abqaiq oil facilities in 2019 shut down more than 5% of worldwide oil output, which was not fully restored for almost three weeks. The 2020 ballistic missile strike on Al-Asad airbase in Iraq forced the U.S. troops there to hunker down and destroyed six hangars, which, had less advance warning been given of the attack, could have resulted in the destruction of several aircraft.
Likewise, the drone attack on the Mercer Street in 2021, as well as multiple earlier mine attacks on commercial vessels, forced the damaged ships to pause their routes or return to port for repairs. The Houthis, using Iran-supplied drones and missiles, have routinely disrupted civilian airport operations in Saudi Arabia through sometimes-lethal strikes on terminals. Iran or its proxies could replicate these methods to disable other infrastructure targets with potentially severe consequences: desalination plants, grain stocks, electric power grids, government buildings, and so on.
To avoid retaliation for such attacks, Iran arrays its conventional assets in an anti-access/area denial posture aimed at raising the cost of any direct military response. But such a defense has limits. Notably, Iran’s anti-access strategy may require more command-and-control capacity than Iran’s dual military possesses. Iran’s air defenses are also unproven and likely insufficiently integrated with the diverse set of target-acquisition capabilities necessary to defeat a concerted attack.
So far, however, Iran has succeeded in deterring a large-scale military response to its asymmetric strikes; none of Iran’s adversaries has retaliated against such a strike by attacking Iran directly, although they have carried out strikes against Iranian proxies, and the United States and especially Israel have occasionally targeted Iranian personnel and assets in Iraq and Syria.
This limited deterrence achieved by Iran likely only applies below a certain threshold—if an asymmetric attack or series of attacks inflicts too much harm on Iran’s neighbors, they and the United States may overcome their reluctance to respond with a direct attack of their own. Iranian leaders therefore have an incentive to walk a strategic tightrope: continuing to gain regional influence by making threats and reinforcing them through periodic small-scale or plausibly-deniable asymmetric strikes, while remaining careful not to overreach and have to put Iran's conventional capabilities to the test in direct combat.
This report drew extensively, though not exclusively, from the following sources:
Dan Gettinger, “The Drone Databook,” The Center for the Study of the Drone at Bard College, 2019, available at https://dronecenter.bard.edu/projects/drone-proliferation/databook/.
“Iran Military Power: Ensuring Regime Survival and Securing Regional Dominance,” Defense Intelligence Agency, November 19, 2019, available at https://www.dia.mil/Portals/110/Images/News/Military_Powers_Publications/Iran_Military_Power_LR.pdf.
“Iranian Naval Forces: A Tale of Two Navies,” Office of Naval Intelligence, February 2017, available at https://www.oni.navy.mil/Portals/12/Intel%20agencies/iran/Iran%20022217SP.pdf.
Missile Defense Project, "Missiles of Iran," Missile Threat, Center for Strategic and International Studies, June 14, 2018, last modified August 10, 2021, available at https://missilethreat.csis.org/country/iran/.
Proliferated Drones, “The Drone Database,” Center for a New American Security, compiled by The Center for the Study of the Drone at Bard College, available at http://drones.cnas.org/drones/.
“Open-Source Analysis of Iran’s Missile and UAV Capabilities and Proliferation,” International Institute for Strategic Studies, April 20, 2021, available at https://www.iiss.org/blogs/research-paper/2021/04/iran-missiles-uavs-proliferation.
John Drennan, “Iranian Unmanned Systems,” December 7, 2017, p. 2, available at https://www.iiss.org/-/media/images/comment/analysis/2017/december/7-drennan2125.pdf?la=en&hash=62D6E91647E0EB1976A2EC42FF3FABF02202A1FF.
Shahryar Pasandideh, "Under The Radar, Iran’s Cruise Missile Capabilities Advance,” War on The Rocks, September 25, 2019, available at https://warontherocks.com/2019/09/under-the-radar-irans-cruise-missile-capabilities-advance/.
Various articles by Tasnim News Agency, https://www.tasnimnews.com/, an Iranian semi-official news organization with close ties to the Islamic Revolutionary Guards Corps (IRGC).
Various articles by The Associated Press, https://apnews.com/ (including multiple articles authored by Associated Press Gulf and Iran News Director Jon Gambrell), Reuters, https://www.reuters.com/, and The Wall Street Journal, https://www.wsj.com/.
Homepage carousel image: Smoke rises from the Abqaiq oil refinery in Saudi Arabia on September 14, 2019. Image credit: Planet (Planet Labs).
 Iran has articulated such strategic goals and attempted to convince its neighbors that it has already attained them. For instance, on November 10, 2020, Iranian Foreign Ministry spokesman Saeed Khatibzadeh declared that, “With the ‘Trump security’ illusion gone, one or two of our neighbouring countries may come to their senses and realize that they cannot always obtain security by paying money and lobbying.” See: “Iran Ready to Help Neighbours Now that ‘Trump Security’ Illusion Gone: Spokesman,” Government of the Islamic Republic of Iran website (irangov.ir), November 10, 2020, available at https://irangov.ir/detail/350750.
 Key sources referenced for Iran’s capabilities include: the U.S. Defense Intelligence Agency (DIA)’s 2019 Iran Military Power report, the U.S. Office of Naval Intelligence (ONI)’s 2017 Iranian Naval Forces report, the Center for Strategic and International Studies (CSIS)’s Missile Defense Project, the Center for a New American Security (CNAS)’s Drone Database, Bard College’s Center for the Study of the Drone, various publications by the International Institute for Strategic Studies (IISS), and articles by Tasnim News Agency, an Iranian semi-official news organization with close ties to the Islamic Revolutionary Guards Corps (IRGC), as well as media reports by a variety of Western news organizations. Iranian claims not corroborated by independent or U.S. Government assessments are indicated as such in the text of the report.
 Precision is the ability of a projectile to impact where it is aimed; accuracy is the ability of a projectile to be aimed in such a manner that it will impact the desired target. Accuracy thus takes into account target acquisition and tracking capabilities. For example, Iran’s development of capable surveillance drones has served to improve the accuracy of its missiles.
 A liquid-fueled missile engine produces more thrust per pound of fuel than a solid-fueled engine, but is more complex and can require many precision-machined and moving parts. Some types of liquid-fueled missiles must also be fueled at their launch site, which makes them easier for an opponent to detect and destroy. Solid-fueled missile engines are easier to maintain and can be stored for many years. Solid fuel also allows for a more rapid launch. Solid-fueled missiles are therefore generally less vulnerable in combat.
 Ballistic missile precision is measured by the concept of circular error probable (CEP): the radius within which, on average, half of all missiles fired will land. For example, given a missile with a CEP of ten meters, if one hundred were launched at a target, on average fifty would land within ten meters of that target.
 Cruise missiles are equipped with rocket boosters for their initial launch; once they are in the air and moving with sufficient speed, their air-breathing jet engine takes over. The distinction between solid fuel and liquid fuel that exists for ballistic missiles thus does not apply in the same way to cruise missiles.
 The IRGC Navy has operational responsibility for the Persian Gulf. Iran’s regular navy operates the country’s handful of capital ships and is responsible for operations beyond the Strait of Hormuz.
 The Persian Gulf is approximately 300 kilometers in width at its maximum width (roughly between Kish Island in Iran and Sir Baniyas Island in the U.A.E.) and approximately 850 kilometers in length, based on measurements taken in Google Maps.
 Iran has three Kilo-class attack submarines that it purchased from Russia in the 1990s. They face maintenance issues and are vulnerable to U.S. conventional forces in the shallow waters of the Persian Gulf.
 Inaccurate conventionally-armed missiles have very little battlefield value, because they require substantial expenditure to yield little effect. For instance, a U.S. Air Force study in 2015 found that 13 Iranian Shahab-1 ballistic missiles (a Scud variant, and the most accurate of Iran’s pre-Fateh missile arsenal) would need to be launched to have a 75% chance of disabling a single military runway—if the missile is equipped with submunitions and without factoring in missile defenses. See: Jacob L. Heim, “The Iranian Missile Threat to Air Bases: A Distant Second to China’s Conventional Deterrent,” Air and Space Power Journal Vol. 29, No. 4 (July-August 2015), pp. 34-35, available at https://www.airuniversity.af.edu/Portals/10/ASPJ/journals/Volume-29_Issue-4/F-Heim.pdf.
 For example, General Hajizadeh in a 2019 interview said, “An aircraft carrier that has at least 40 to 50 planes on it and 6000 forces gathered within it was a serious threat for us in the past but now... the threats have switched to opportunities… If [the Americans] make a move we will hit them in the head.” See: “Iran's Guards commander says U.S. military presence in Gulf is 'an opportunity': ISNA,” Reuters, May 12, 2019, available at https://www.reuters.com/article/us-usa-iran-commander/irans-guards-commander-says-u-s-military-presence-in-gulf-is-an-opportunity-isna-idUSKCN1SI087.
 At a minimum, close coordination between the IRGC Navy, the regular navy, and the IRGC Aerospace Force would be necessary, as well as between the various forces comprising the IRGC Navy (fast inshore attack craft “swarms” and their supporting missile boats, for instance). Recent blunders, such as the accidental shooting down of a civilian airliner near Tehran in January 2020 and the deadly striking of a friendly naval support ship with an ASCM during an exercise later that year, cast some doubt on Iran’s ability to execute its preferred tactics.
 In the words of Iran’s Supreme Leader Ali Khamenei, in a speech delivered in 2021: “Today, our defensive power is such that our enemies have no choice but to take Iran’s capability into consideration. When the missiles of the Islamic Republic are able to strike the transgressing US drone, when they are able to demolish the Ain al-Asad Airbase, then the enemy will be forced to take our country’s power and capability into account when he wants to make calculations or make military decisions. We should not leave the country defenseless. This is our responsibility. We should not do something to give the enemy the boldness to attack and to render ourselves defenseless in front of him.” See: Ali Khamenei, “The U.S. is in a miserable state,” Khamenei.ir, January 8, 2021, available at https://english.khamenei.ir/news/8264/The-U-S-is-in-a-miserable-state.