Iran's growing use of cluster-warhead ballistic missiles is changing the mathematics of missile defense. From Israel to the recent attack on a U.S. air base in Jordan, one missile that survives interception can disperse dozens of submunitions""turning one incoming target into many.

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Iran's Cluster Warheads: The Weapon That Keeps Getting Through

From the 12-Day War to the 39-Day War and Now Jordan

Iran's ballistic-missile campaign has undergone an important evolution that has received less attention than the range, velocity, and number of the missiles themselves. Tehran has increasingly employed ballistic missiles carrying cluster warheads: payloads designed not to concentrate their explosive energy at a single impact point, but to disperse numerous smaller explosive submunitions across a broad area. Iran demonstrated this capability during the 12-Day War with Israel in June 2025, expanded its use dramatically during the much larger conflict that began on February 28, 2026, and has now employed cluster-carrying ballistic missiles in an attack against American forces at Muwaffaq Salti Air Base in Jordan.

The military significance of this development is greater than simply adding another warhead to Iran's missile inventory. Cluster warheads change the geometry of missile defense. Against a conventional unitary ballistic warhead, the defender detects, tracks and attempts to destroy an incoming target before impact. A cluster-carrying ballistic missile presents a different problem. Before its payload separates, it remains essentially one incoming target. Once the carrier releases its submunitions, however, the defender may suddenly confront dozens of smaller objects descending independently toward different points across a broad area.

Reuters reported in March 2026 that Iranian cluster warheads typically contain approximately 24 submunitions, each carrying roughly two to five kilograms of explosives, and that the payload separates at an altitude of approximately seven to ten kilometers. The defensive implication is crucial. Israeli defense specialist Yehoshua Kalisky explained that the carrier must be intercepted before it releases its cluster payload. Once the submunitions have dispersed at relatively low altitude, intercepting the individual bomblets becomes extraordinarily difficult.

This does not mean that cluster-warhead ballistic missiles are intrinsically unstoppable. It means that the timing of interception becomes exceptionally important. A successful high-altitude interception can eliminate the carrier and its entire payload simultaneously. A missile that penetrates far enough to release its submunitions has already transformed the defensive problem, even if the defender has intercepted most of the other missiles in the salvo. Consequently, a very high overall interception percentage can coexist with significant damage on the ground.

The First Battlefield Experiment: The 12-Day War

The first important battlefield evidence appeared during the June 2025 Israel-Iran war. On June 19, Iranian forces launched a ballistic missile carrying cluster submunitions toward central Israel. Amnesty International subsequently reported that approximately 20 submunitions were dispersed over an estimated eight-kilometer area. Amnesty also found evidence consistent with cluster-munition strikes in Beersheba on June 20 and Rishon LeZion on June 22.

The importance of these attacks was not primarily their immediate destructive effect. They demonstrated that Iran possessed a ballistic-missile payload capable of converting one missile into numerous geographically separated impact points during the terminal stage of flight. The 12-Day War therefore provided Iran with something militarily more valuable than a weapons demonstration: combat experience against one of the world's most sophisticated layered missile-defense networks.

The attacks also demonstrated the weapon's inherent humanitarian problem. Cluster munitions disperse their effects over a broad area, and some submunitions may fail to explode on impact, leaving dangerous unexploded ordnance. Amnesty International concluded that Iran's use of cluster munitions in populated areas during the 12-Day War violated international humanitarian law. The military characteristic that makes these weapons useful against dispersed targets-- their ability to spread numerous explosive devices over an area-- is also what makes their employment in populated areas particularly dangerous to civilians.

From Experiment to Routine Weapon

The scale changed dramatically after the joint American-Israeli attack on Iran on February 28, 2026. By March 18, Reuters reported that Iran had launched dozens of cluster-warhead ballistic missiles against Israel and that, according to the Israeli military, approximately half of the Iranian missiles fired since February 28 carried cluster payloads. What had been an unusual feature of the 2025 war had become a substantial component of Iran's missile campaign.

Human Rights Watch independently examined extensive visual evidence from the attacks. Its researchers reviewed videos and photographs of suspected Iranian cluster-munition use between March 1 and March 20. Numerous videos showed descending ballistic missiles surrounded by suspected submunitions. Most showed approximately 21 to 25 objects descending around the missile, while some showed considerably more. Human Rights Watch concluded that Iran had repeatedly employed cluster munitions delivered by ballistic missiles during the conflict.

The consequences became unmistakable around metropolitan Tel Aviv. Cluster-munition attacks killed civilians and damaged infrastructure. The important military lesson, however, was not simply the destructive power of an individual bomblet. It was the multiplication of potential targets once the carrier missile had survived long enough to disperse its payload.

The Problem for Patriot, THAAD and Layered Missile Defense

This is where the distinction between a conventional ballistic warhead and a cluster payload becomes particularly important. Modern systems such as Patriot PAC-3 and THAAD are formidable ballistic-missile defenses, but their basic task is to detect, track and destroy threatening ballistic targets. PAC-3 uses hit-to-kill interceptors against tactical ballistic missiles and other aerial threats, while THAAD is designed to intercept ballistic missiles during the terminal portion of their flight.

Against a cluster-carrying ballistic missile, however, there is an important transition. Before payload separation, Patriot, THAAD, Arrow or another interceptor can attempt to destroy the carrier as a single ballistic target. If that interception occurs sufficiently early, the cluster payload can be eliminated with it. But once the carrier descends to the release altitude and disperses perhaps two dozen submunitions, the defensive geometry changes radically. What had been one tracked ballistic target becomes numerous small objects descending independently and spreading geographically as they fall.

This is the essential problem posed by the cluster warhead. Patriot and THAAD were designed to intercept ballistic missiles, not to transform one interceptor engagement into the simultaneous destruction of dozens of small falling bomblets after dispersion. Before separation, the defense is fighting one incoming ballistic target. After separation, it may be confronting 20, 24 or more independent submunitions spread across the defended area. The opportunity to destroy the entire payload with a single successful interception has largely disappeared.

The distinction is particularly important because the Iranian payload reportedly separates at approximately seven to ten kilometers altitude. By that stage, the remaining flight time is short. The individual submunitions are small, numerous and geographically separating as they descend. The central defensive objective is therefore to destroy the carrier missile before it reaches the point at which one target becomes many.

This also explains why interception percentages can be misleading. If 20 ballistic missiles are launched and 18 are intercepted, the apparent defensive success rate is 90 percent. With conventional unitary warheads, the remaining problem is essentially two surviving warheads. But if even one surviving cluster carrier reaches its release point with approximately 24 submunitions, the relationship between missiles penetrating the defense and explosions occurring within the defended area is no longer one-to-one. One successful penetration can generate numerous potential impact points.

Why Air Bases Are Particularly Vulnerable

The military utility of such a weapon becomes especially apparent when the target is an air base. A hardened underground command center is generally more appropriately attacked with a large, accurate unitary or penetrating warhead. An airfield has a fundamentally different geometry. Aircraft can be distributed across ramps, shelters and dispersal areas, while fuel trucks, maintenance equipment, radar systems, communications equipment, ammunition-handling facilities and personnel may occupy widely separated locations.

Against such a target, concentrating all explosive energy at one point is not necessarily advantageous. Area coverage itself has military value. A cluster carrier that penetrates the defense and releases numerous submunitions above an airfield can threaten several separated assets even though each individual bomblet possesses far less destructive power than a large unitary ballistic-missile warhead.

That characteristic makes Iran's September attack on Muwaffaq Salti Air Base in Jordan particularly important. On September 8, Iran launched approximately 20 ballistic missiles toward the American-operated base near Azraq after U.S. forces destroyed five Iranian crude-oil tankers. Jordan initially announced that its defenses had intercepted 18 of the 20 missiles and that the remaining two had fallen in unpopulated areas. There were no reported casualties. On the basis of those numbers alone, the attack initially appeared to have been overwhelmingly defeated.

The subsequent evidence complicated that picture. The Institute for the Study of War reported on September 9 that Iran had employed cluster-munition ballistic missiles in the attack on American forces at Muwaffaq Salti. The precise number of cluster-equipped missiles in the salvo remains uncertain.

Then came evidence of actual aircraft damage. On September 10, Reuters reported that an A-10 Thunderbolt II had suffered major damage and lost a wing, while approximately eight F-15 fighters sustained lighter damage and were subsequently returned to service. Later reporting attributed the damage directly to the Iranian attack. The available public evidence does not yet establish which individual missile or submunition produced each instance of damage. Nevertheless, the combination of cluster-warhead use and damage to multiple American combat aircraft makes the Jordan attack militarily significant.

The apparent contradiction is itself instructive. Jordan reported intercepting 18 of 20 missiles-- an apparently impressive 90 percent interception rate-- yet American aircraft were damaged. This illustrates why missile-defense effectiveness cannot be measured solely by counting the percentage of incoming missiles destroyed. The more important question may increasingly be what the missiles that survive are carrying.

Jordan and the Expansion of the Battlefield

Jordan also has strategic significance beyond the aircraft stationed at Muwaffaq Salti. The country is a longstanding American security partner and hosts important U.S. military operations. Geography makes it different from American installations elsewhere in the Persian Gulf because Jordan borders Israel. Iranian ballistic missiles approaching Jordan therefore enter an exceptionally sensitive defensive environment in which American, Jordanian and Israeli warning and missile-defense systems must rapidly determine trajectories and intended targets.

The September attack also occurred within a broader escalation between Iran and the United States. U.S. forces destroyed five Iranian oil tankers on September 8 following Iranian attempts to strike American naval vessels. Iran retaliated against the American base in Jordan and subsequently expanded attacks against shipping. The confrontation increasingly extended beyond exchanges against fixed military installations and into the maritime routes through which a substantial portion of the world's energy supply normally passes.

The Jordan attack therefore should not be understood as an isolated missile exchange. It forms part of a broader transition in which Iran appears increasingly willing to expose sophisticated American military assets directly to its missile arsenal, while the United States is increasingly willing to attack Iranian economic assets in response.

A Weapon Refined Through War

The progression is striking. During the 12-Day War of June 2025, Iran demonstrated the ability to deliver cluster submunitions by ballistic missile against Israel. During the conflict beginning in February 2026, Iran greatly expanded their use, with Reuters reporting by mid-March that approximately half of Iranian missiles fired at Israel were believed by the Israeli military to carry cluster warheads. By September, Iran had employed the same general method against an American air base.

This is battlefield adaptation. Iran has suffered extensive damage to its conventional military infrastructure during successive Israeli and American attacks. Under those conditions, increasing the effects produced by missiles that survive interception becomes increasingly valuable. Cluster warheads offer one method of doing so. They do not make Iranian ballistic missiles invulnerable, nor do they guarantee penetration. Against hardened point targets they may be considerably less useful than large conventional warheads. Against airfields, troop concentrations and infrastructure distributed across a broad area, however, a single successful carrier can generate numerous potential impact points.

The arithmetic of missile defense consequently changes. The traditional questions remain important: How many missiles can Iran launch? How many interceptors are available? What percentage of the incoming missiles can be destroyed? But cluster warheads introduce another variable: What happens after the missile penetrates? A conventional ballistic missile that survives interception generally remains one incoming warhead. A cluster carrier that survives until payload separation can transform one penetration into many geographically separated explosive threats.

There is an additional economic dimension. Defensive interceptors are sophisticated and expensive weapons produced in finite numbers. The September attack on Jordan reportedly required the expenditure of roughly 30 Patriot interceptors. A strategy that obliges the defender to expend large numbers of advanced interceptors while requiring only a small number of attacking missiles to survive long enough to disperse their payloads creates an additional form of pressure: not simply penetration of the defense, but consumption of the defensive inventory over time.

The Dangerous Lesson

Wars teach armies, and the lessons are rarely learned by only one side. Israel learned from the 12-Day War. The United States learned from it. Iran did as well. One lesson Tehran appears to have drawn is that defeating an entire missile-defense architecture may not be necessary. If a sufficiently small number of missiles survive long enough to reach the correct phase of flight, the payload itself can multiply the consequences of penetration.

There is also a serious humanitarian dimension. Cluster munitions scatter submunitions across wide areas, and unexploded bomblets can remain dangerous long after an attack. Human Rights Watch has documented civilian deaths from Iranian cluster strikes in Israel, while Amnesty International concluded that their use in populated areas during the 12-Day War violated international humanitarian law. Reuters reported on September 8 that cluster munitions killed or injured at least 1,063 people worldwide during 2025, 87 percent of whom were civilians.

More than 100 countries have joined the Convention on Cluster Munitions, although Iran, Israel and the United States are not parties. The humanitarian controversy surrounding these weapons is inseparable from the military characteristic that makes them attractive: their ability to distribute explosive effects across an area rather than concentrate them at a single point.

The important development is the progression from experimentation to repeated operational use. In June 2025, Iran demonstrated cluster-warhead ballistic missiles against Israel. In early 2026, it employed them extensively and demonstrated that some could survive long enough to disperse their payloads despite sophisticated missile defenses. In September 2026, cluster-carrying missiles were reported in an attack against an American air base in Jordan, after which multiple American combat aircraft were reported damaged.

The Iranian missile threat therefore can no longer be adequately evaluated simply by counting launches and interceptions. The more consequential question is increasingly what the missiles that survive are carrying, and whether they can be destroyed before one target becomes many.

Jordan may have just demonstrated why.

References

1. Reuters. "Iranian cluster missiles pose extra challenge for Israel's air defences." March 18, 2026.

2. Amnesty International. "Iran/Israel: Iranian forces' use of cluster munitions in '12 Day War' violated international humanitarian law." July 24, 2025.

3. Human Rights Watch. "Iran: Unlawful Cluster Munition Strikes on Israel." March 2026.

4. Critical Threats Project/Institute for the Study of War. "Iran Update Special Report." June 20, 2025.

5. Institute for the Study of War. "Iran Update." September 9, 2026.

6. Reuters. "Iran retaliates against US allies after its oil tankers destroyed." September 8, 2026.

7. Reuters. "Iran and US hit tankers in biggest wave of attacks on shipping since war began." September 9, 2026.

8. Reuters. "Multiple US military aircraft suffered damage in overnight strikes on Jordan air base." September 10, 2026.

9. U.S. Army. "U.S. Army Advances Accelerated PAC-3 MSE Production Through Contract Action." April 10, 2026.

10. U.S. Missile Defense Agency. "Terminal High Altitude Area Defense (THAAD)." Current system overview.

11. Reuters. "Cluster bomb casualties near record, driven by war in Ukraine." September 8, 2026.

12. Associated Press. "Jordan's alliance with the US makes the kingdom a target for Iranian strikes." September 2026.

Authors Bio:

I was born and raised in Tehran, Iran, and came to the United States in 1976 to study psychology. Over time, America became my home, and I later became a U.S. citizen. My professional career has centered on clinical neuropsychology, particularly the evaluation and rehabilitation of patients with neurological disorders and stroke. I also spent many years teaching and mentoring students in academic settings, including at Northeastern Ohio Medical University. In addition to my clinical work, I have been involved in research on neurological conditions, including hemianopsia, and have written articles and books on a variety of subjects. Growing up in the Middle East during a period of profound political and geopolitical change fostered an early interest in history, regional affairs, and international politics. As an undergraduate, I minored in Iranian history, and for decades I have maintained a strong personal interest in military affairs, strategic studies, and the psychology of political leadership. These interests have complemented my professional work and continue to inform my analysis of international conflicts. My interests have always extended beyond psychology. History, anthropology, politics, and culture have long fascinated me, and they continue to shape both my writing and my understanding of human behavior. Much of my work explores the intersection of psychology, leadership, history, military strategy, and international affairs. Today, I am semi-retired and devote much of my time to writing, reading, painting, producing educational podcasts, and playing the Tar, a traditional Persian instrument. Having lived under very different political and cultural systems, I have developed a deep appreciation for freedom of thought, critical inquiry, and open dialogue. While I do not follow a particular religion, I respect the important role that faith plays in the lives of many people. Above all, I remain curious about the human condition and committed to understanding the forces that shape individuals, societies, and history.