The U.S. Can Choose Between a Narrow or a Broader Operation Against Iran's Navy

Guided-missile destroyer USS Thomas Hudner (DDG 116) patrols the Strait of Hormuz, July 27, 2023.

The operation was both a military success, with only 2 U.S. fatalities, and a diplomatic success, in that the U.S. deterred escalation or retaliation for the next forty years. It also boosted the credibility of U.S. security assurances to ensure that shipping lanes would remained open. This sharp action, and Iran’s resulting isolation, was a contributing factor that led Tehran to seek an end to the Iran-Iraq War. However, the deterrent impact of this intervention is nearly two generations old, with every major contemporary Iranian political and military decision-maker now deceased. In fact, the current commander of the Iranian Navy, Shahram Irani, was only twenty years old at the time.

The political outcome was all the more remarkable given that simulations of retaliation typically show that Iran, rather than the U.S., has the advantage of escalation dominance in the region. The ease of camouflage and dispersal makes the reliable destruction of land-based anti-ship missile (ASM) batteries by remote bombardment, whether by ship or air, very difficult, without also landing raiding parties along the Iranian coast. In fact, no coastal ASM has ever been confirmed destroyed from an offshore bombardment, and ASMs can inflict high losses, as the Argentines did with an Exocet strike against the HMS Glamorgan during the 1982 Falklands Campaign.  

On-station USN platforms in the Persian Gulf region, under the command of the Fifth Fleet of the U.S. Naval Forces Central Command (NAVCENT), include the USS Paul Hamilton (DDG-60) and USS McFaul (DDG-74). U.S. aircraft also operate out of Isa Air Base in Bahrain, Al Udeid Air Base in Qatar, Al Dhafra Air Base in the United Arab Emirates, and make use of Prince Sultan Air Base for logistics. The 379^th and 380^th Air Expeditionary Wings deployed there operate RC-135W reconnaissance aircraft, E-8C JSTARS, and P-3C Orion and P-8 Poseidon maritime patrol and anti-submarine capable aircraft. Al Udeid has also hosted F-22 fighter jets and B1 bombers in past contingencies.  Al Dhafra also launches RQ-4 and EQ-4 drone patrols.

Iran has also recently launched large-scale exercises in the Persian Gulf region, as reported by their state media on July 24^th, involving over 90 aircraft and combat drones. The Iranian Navy’s Southern Fleet comprises nine Kaman and one Sina-class fast attack crafts, two Bayandor corvettes, three Moudge frigates, and three Alvand-class frigates. The parallel IRGC Navy also has one Shahid Soleimani and one Shahid Nazeri missile corvette, as well as 126 smaller coastal and patrol vessels, of which 56 are armed with ASMs, and a further 15 are torpedo-armed Peykaap-I ships. The most potent branch of the Iranian navy is its force of 27 submarines, which include fifteen mini-submarines optimized for the shallow and acoustically muffled waters of the Gulf. Iran also possesses three potently silent Kilo class subs, which while not optimal for the Gulf, pose a serious challenge to any flotilla operating in the Arabian Sea, such as a U.S. carrier group. Given the dependence of the USN on aircraft for its shallow-water anti-submarine warfare (ASW) capability, such as the SH-60 helicopters deployed on U.S. aircraft carriers and its escorting Arleigh Burke destroyers, or the P-8, the U.S. must first achieve air superiority before it can sweep away Iranian subs in the shallows of the Persian Gulf. 

The Iranian Air Force’s shrinking and obsolescent aircraft will struggle to approach U.S. surface ships or bases, but the constrained waters in the Persian Gulf will hamper U.S. air defenses against a concentrated barrage of anti-ship missiles. Iranian aircraft with a modicum of combat capability include 63 F-4D, 19 MIG-29, 12 Mirage F1EQ (12 aircraft), and 23 Su-24. A bigger challenge is that Iran has MIM-23 Hawk, HQ-2J and S-200VE Vega surface to air missile (SAM) batteries deployed at its 9^th Tactical Airbase at Bandar Abbas. This gives Iran an over-watch of 240 kilometers range, effectively over the entirety of the Straits of Hormuz and its approaches, enabling an Iranian Anti-Access/Area Denial A2/AD) capability. There are also 50-km range Hawk SAMs at Chabahar in the Arabian Sea, at the entrance of the Gulf, and on the island of Abu Musa, which is at the Western entrance of the Straits of Hormuz. On the Western shore of Iran, which vitally oversees the substantial export of oil from Iraq, Kuwait and Saudi Arabia, are Sayyad-2 Talash, S-300PMU2 Favorit, and S-200VE Vega SAMs at the 6^th Tactical Air Base near the port city of Bushehr.

Any stand-off U.S. cruise missile or aircraft strikes on Iranian targets will likely be reciprocated, and will not solve the problem of entrenched and dispersed ASM sites. Any U.S. action focusing on temporary seizure of Iran’s islands and littoral bases, will require persistent suppression of Iran’s local air defense and submarine assets, in that order. Suppression of Enemy Air Defence (SEAD) would likely involve MQ-9 Reaper drones and EA-18G Super Hornets launching the AGM-88 Harm and ADM-160 MALD, and conducting jamming. The use of attack aircraft, such as the F-35 and F-22, will greatly reduce the size and risk of operating against Iran’s S-300 SAM systems. A relative unknown of this scenario is the capability and effectiveness of Iran’s domestically produce Sayyad-4B surface-to-air missile, with the missile successfully engaging a target at over 300 kilometers according to Iranian media. Iran also reported that its Bavar-373 radar system is capable of detecting targets up to 450 kilometers.

Any plan of attack must be closely linked to a diplomatic strategy that achieves stable combat termination. Escalation is far less likely if the U.S. limits its targets to the IRGC Navy, as well as IRGC-controlled oil rigs, and the IRGC’s missile corvettes which are responsible for seizures and harassment activity in the Gulf: the Shahid Soleimani and Shahid Nazeri. A limited attack may cause less of a provocation to Tehran, but the associated destruction required by the need to counter-act Iran’s air defenses and submarines, may make that intention opaque. This limited approach would also leave Iran with a still sizeable amount of naval assets in the region, which it could use to risk the security of U.S. and its allies’ bases and forces in Gulf. Furthermore, this curb on the full demonstration of U.S. capability may be interpreted as political weakness and embolden Iran and even Russia and China, and even invite an acceleration of even closer relations with Moscow and Beijing.

Alternately, a broader attack plan would strike the Iranian Navy’s more capable Bayandor-class corvettes, Moudge-class frigates, and the military installations on a number of Iran’s aforementioned islands. The amphibious assaults would provide an early test of the U.S. Marine Corps new concept of operations it is preparing for operations in the South China Sea, the Taiwan Strait and in the Philippines, in particular vertical envelopment, and the supplanting of armor and tube artillery for guided missiles. An offensive operation with a wider goal of destroying Iranian naval platforms and air bases, would need to threaten a continuance of the conflict, by highlighting other targets in Iran’s interior, in order to deter a determination in Tehran to risk continuing the conflict. The war termination logic for the broader attack scenario, is that authoritarian regimes like Tehran, which depend on coercive forces to remain in power, will be cowed by the destruction of these formations. Furthermore, the scale of violence will interfere with Iran’s energy exports and its ability to subsidize its economy. It is a militarily attainable goal from a technical standpoint, yet it would nevertheless require a large post-conflict deployment to deter the Iranian air force and long-range missile forces.

A successful operation in the Persian Gulf would demonstrate U.S. willingness to apply force elsewhere, such as the Black Sea, Baltic, the Russian Arctic, and on the Pacific littoral. While conflict with the U.S. may push Tehran closer to Moscow, Beijing, and Pyongyang, war limitations and economic woes will limit any material aid to Iran from those quarters, and will likely decrease Iranian arms transfers to Moscow. Despite Iranian rapprochement with Saudi Arabia and the Emirates, Riyadh is unlikely to intervene unfavorably to Washington, and Baghdad will support any move that curtails Iranian influence in Iraq’s politics.

Alexandru Filip, Ph.D., is an International Relations student at Concordia University, Montreal, and an analyst and editor at the Canadian Center for Strategic Studies research institute.

Julian Spencer-Churchill, Ph.D., is an associate professor of international relations at Concordia University (Montreal), former army engineer officer, and has written extensively on Pakistan, where he conducted field research for over ten years.