The first real test of naval defenses against anti-ship cruise missiles occurred in 1973. Unlike the Pakistanis, the Israelis had adapted quickly, and they were able to weather a massive attack from Syrian and Egyptian P-15s using chaff and active jamming. Dozens of P-15s were fired, but none hit the Sa’ar-class missile boats equipped with countermeasures.

The record of the anti-ship cruise missile has been decidedly mixed since then. The famous sinking of the HMS Sheffield by an Exocet anti-ship cruise missile during the Falklands War has been justifiably categorized as a fluke. The Sheffield’s ESM was temporarily degraded while it was transmitting over satellite, and airborne early warning wasn’t active. Iraqi Exocets killed 37 American sailors aboard the USS Stark in 1987, but the Americans had no reason to think they were at risk of attack by a loose ally. Hezbollah successfully struck the INS Hanit with a cruise missile in 2006, but the Israelis claim they hadn’t turned on any defensive systems because they were totally unaware Hezbollah even possessed anti-ship missiles. Recent events may provide examples of external defenses failing. American naval vessels have been unable to protect commercial ships that may or may not be within their defense envelope, but it isn’t outrageous to claim that no unambiguous examples of an ASCM striking a critical blow on a well-prepared and defended military vessel exist.

This is because ASCMs suffer from shortcomings of their own. Active radar seekers announce themselves, allowing ECM systems to detect them consistently, and often before the missile detects its target. Chaff is highly effective against active radar seekers. Other seeker types avoid these problems while introducing others. Infrared seekers are passive, but have limited range and suffer in certain weather and environmental conditions. They can be defeated with IR decoys. Active TV guidance requires a constant datalink, which limits range and makes the system susceptible to jamming. Combining these seeker types can make a system more robust to countermeasures, but this does nothing to mitigate the most severe drawback of cruise missiles compared to ballistic systems: their slow speed makes them comparatively trivial to shoot down.

The war in Ukraine has provided all the evidence one could want of this fundamental reality. Videosof cheap MANPADS shooting down Russian cruise missiles are plentiful. Even advanced, stealthy cruise missiles like the Storm Shadow are routinely shot down by Russian air defenses.

What Iran Has

While Iranian medium-range ballistic missiles (MRBMs) enjoy an impressive penetration rate against US and Israeli air defense systems, there’s no reason to expect this to carry over to the performance of Iranian cruise missiles against American naval systems. The difference in speed between the two types of projectiles is enormous. Some combination of raw speed and maneuvering capability makes Iran’s most sophisticated ballistic missiles a clear overmatch for the most advanced American and Israeli air defense systems. Based on the information we can verify, no cruise missile system fielded by any military enjoys this overmatch. Hypersonic cruise missiles like the Russian Zircon have yet to be used against a naval target in combat.

The Wall at 150 Miles

Clockwise from top left: SM-6, RIM-162, RIM-116, Phalanx CIWS

The defensive systems the Iranians are up against in the Arabian Sea are extensive. Two Carrier Strike Groups contain over 700 VLS cells, with a generous portion of those committed to the SM-6 missile interceptor, which was specifically designed to intercept ASCMs. Each carrier can launch multiple E-2D Advanced Hawkeye airborne early warning aircraft, which help negate low-altitude sea-skimming ASCMs by detecting them much earlier than a surface vessel could. Radar systems in a CSG are integrated, allowing vessels to launch interceptors against targets only another vessel can detect. Incoming ASCMs must first get past the SM-6, then RIM-162 interceptors, followed by RIM-116, and then finally the last-ditch Phalanx CIWS. The AN/SLQ-32 EW suite detects and jams guidance radars. The Australian Nulka system deploys active decoys designed to draw the guidance systems of ASCMs off target, and the BAE Mark 36 SRBOC deploys chaff and infrared decoys. A carrier’s air wing can take down drones.

Map: AmerikanetsSource: @MoloWarMonitor on XCreated with Datawrapper

Despite all these layers of defenses, the American CSGs in the theater have been extremely cautious. The CSGs themselves loiter cautiously behind an invisible barrier 150 nautical miles (278 km) from the Iranian coast, rarely venturing beyond it. The distance is telling. Allow perhaps 30 kilometers between the coast and a plausible launcher position, and the CSGs sit just beyond the reach of most Iranian ASCMs. This shows they take the threat seriously, but it allows them to continue to sortie aircraft to strike Iran.

Iran's Anti-Ship Ballistic Missiles

Based on the heritage of these systems, there’s little reason to expect them to enjoy the same advantages as Iran’s most advanced medium-range missiles, and they don’t present evidence that Iran has solved the fundamental problems in ASBM design. The publicly stated range of these systems suggests they have the profile of a short-range ballistic missile (SRBM), and the accordingly lower speeds of short-range ballistic systems. There’s no evidence they can perform complex evasive maneuvers while still hitting their target, which is itself moving. The profile of their trajectory is unknown. They may have trouble dealing with the evasive maneuvers that satellite imagery shows American ships performing.

Recipe for Success

Legenda

A P-700 Grant is loaded into a Project 949A cruise missile submarine

This was the first true end-to-end aircraft carrier kill chain, with every component designed from the ground up to destroy an American CSG specifically. The Soviets were the only power on earth with the resources and motivation to deploy the world’s first (nuclear powered!) dedicated naval ISR satellite constellation. But the Granit wasn’t fielded until 1983, and the full Legenda constellation wasn’t deployed until 1988. The program faced massive technical challenges and multiple major setbacks, which is unsurprising considering its complexity and ambition. Gorbachev cancelled it the same year the last satellite in the constellation was launched, and Legenda was already heavily degraded by the time the USSR collapsed in 1991. Legenda also lacked what we’ve already identified as the silver bullet for overcoming air defenses: an extremely fast, highly accurate anti-ship ballistic missile.

East Wind

The Chinese have launched hundreds of ISR satellites into orbit, with their total in orbit increasing by a factor of six from 2018 to 2026. These include what are speculated to be dedicated constellations just for tracking American aircraft carriers. The scale of these constellations dwarfs Legenda’s, which could only provide short windows of active radar tracking. And crucially, the Chinese claim to have developed geostationary synthetic-aperture radar ISR satellites that allow uninterrupted tracking of an individual target, which is otherwise impossible given the narrow viewing window of SAR.

Combined with over-the-horizon radar, ship-based radar, and AWACS, it’s plausible to say that the Chinese are capable of knowing the precise location of an American aircraft carrier in the Pacific for lengthy, uninterrupted periods, or perhaps at all times. This is the first major problem to solve in developing a true carrier killer.

The Chinese fielded the first operational ASBM in history, the DF-21D, in 2010. Because the DF-21D has never been used in combat, and its specifications are classified, we can only speculate on how closely its claimed capabilities match reality. But its general profile is thought to be a maneuvering MRBM with a very low (estimates are 20 m) CEP, a terminal phase active radar seeker, and a 1500 km range. The DF-21D is commonly cited as having a Mach 10 “terminal phase,” though this is likely its speed at atmospheric re-entry. In order for the active radar seeker to function, it probablyslows down significantly, to around Mach 2, before impact. This is how the American Pershing II IRBM worked, engaging in a “pull up” maneuver so its active radar seeker could compare the ground below it against preloaded terrain maps.

Pershing II trajectory

The Chinese have developed a succession of more advanced anti-ship systems since the DF-21D was introduced in 2010 (be warned, the following information is highly speculative). The DF-26 is an IRBM that builds on the DF-21D with nuclear capability and increased range. The Chinese have tested it against full-scale (non-moving) mockups of Gerald R. Ford-class carriers and Arleigh Burke-class destroyers. The YJ-20, a naval-launched, hypersonic ASBM, appeared in 2025. Its biconic design should theoretically allow much higher terminal speeds and greater maneuverability than a traditional blunt cone reentry vehicle.

Also of note are Chinese hypersonic glide vehicles (HGVs), of which it has fielded at least three. An HGV moves in a flat trajectory while skipping along the atmosphere. They trade raw speed at impact for maneuverability, and various militaries claim they’re capable of extreme maneuvers that would never be possible with a traditional missile design. Their trajectory makes them immune to high altitude defense systems like the THAAD and Arrow-3. The open question is whether any of these is truly capable of active terminal guidance against a moving target. There’s no real evidence they are, and even so, an HGV doesn’t necessarily impact its target at high Mach, making it theoretically possible for it to actively seek a target, but also feasible to intercept.

 

While it’s reasonable to assume that HGVs will defeat high-altitude naval defenses like the SM-3, which has a minimum intercept altitude around 100 km, lower-tier interceptors may still pose a threat to them. The high terminal speed/maneuverability combination that’s made Iranian missiles so deadly may not have an ASM equivalent due to the complexities involved in designing an active seeker that can function at high Mach.

There’s little public information on the state of the art in high-Mach seekers. The Iranians themselves appear to be pushing the envelope here and claim the Qassem Bassir, arguably the most advanced Iranian MRBM, is equipped with an infrared electro-optical seeker that functions at speeds greater than Mach 5, giving the system “meter-level” accuracy. But this is supposedly a scene-matching system designed for use against static land targets, freeing it from the constraints that make ASBMs so challenging to design. And there’s no evidence yet of the Mach 5 impact claim.

But there are reasons to think this problem is solvable. Here we step from the realm of the unconfirmed to the purely speculative. The Chinese have devoted enormous resources to plasma research, and Chinese scientists have claimed major breakthroughs in passing signals through plasma. Advancements here would go a long way towards resolving the fundamental constraints in ASBM design. The first is constant, external guidance at hypersonic speeds. We’ve already covered that a military actor like China can track the real-time position of a moving naval target using its ISR network. If that network can provide constant updates to a hypersonic missile during its flight, the pressure on the missile’s onboard seeker is greatly decreased because the search space shrinks massively. The Chinese have also possibly found solutions for seeking through the plasma sheath.

It’s plausible that the Chinese possess a reliable, operational carrier killer today, and that they’re the only nation to ever have one. But this should be regarded as a holistic system, rather than just a particular missile. All the components in a highly sophisticated and staggeringly expensive chain reaching from the launcher on the ground to ISR satellites in space must work together.

So where does this leave the Iranians? First, none of this proves Iran hasn't chosen restraint. What it does establish is that restraint is a more logical choice than it may at first appear. The Iranians don’t have the resources to create an integrated space-based ISR system like the Chinese have. Their coastal radars have suffered attrition. They’ve made massive leaps in missile technology, but this is just one link in a lengthy chain. Their best bet for the moment is attriting American naval defenses with cruise missiles and drones, but this is a tall and expensive order. A single CSG has hundreds of interceptors capable of shooting down slower aerial threats. Its radars, unlike the terrestrial ones the Iranians have already destroyed, are mobile. And American naval forces are intentionally operating at the edge of Iranian cruise missile range. The Iranians could expend hundreds of cruise missiles without much to show for it. Perhaps the most realistic possibility for the Iranians to get an edge on American naval forces would be getting a little help from their friends. Chinese and Russian ISR could greatly diminish Iran’s disadvantages in targeting, but it remains to be seen if either state would be willing to take that risk.

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