The cluster warheads Iran has been launching toward Israel may generate psychological alarm, but defense officials say they are relatively primitive, inexpensive and unsophisticated weapons that do not warrant the development of a unique technological countermeasure.
Security officials draw a distinction between a cluster warhead and a multiple independently targetable reentry vehicle, or MIRV — a capability believed to be limited to major military powers and not known to be in Iran’s arsenal.
Cluster warheads
A MIRV carries several medium or large warheads that separate from the missile while still outside the atmosphere, with each reentry vehicle maneuvering independently toward a designated target. By contrast, the cluster warheads used in some Iranian ballistic missiles release dozens of smaller explosive submunitions.
Security sources who spoke to Calcalist said the cluster warheads replace heavier high-explosive warheads weighing between roughly 400 kilograms and one metric ton. Instead, they carry smaller munitions weighing between about 2.5 kilograms and 5 kilograms each.
If not intercepted outside the atmosphere by the Arrow 3 missile defense system, the missile opens at an altitude of about 8 kilometers (5 miles) and scatters its contents over a radius of roughly 10 kilometers (6 miles). Submunitions from a single missile can therefore create multiple impact sites, sometimes across several communities within that radius.
A typical cluster warhead can carry about 25 to 30 munitions weighing around 2.5 kilograms each. When the submunitions weigh closer to 5 kilograms, the number is lower, about 10 to 15.
Defense experts say the falling submunitions are not guided and function as what they describe as a “statistical” weapon, similar in effect to the Grad rockets fired in large quantities by Hamas from the Gaza Strip in past conflicts. The destructive power of each individual submunition is relatively limited and comparable to that of a Grad rocket. However, without adequate shelter, their explosions can cause fatalities and serious injuries.
Even when interceptions occur at high altitude and far from Israeli territory, not all submunitions carried in a cluster warhead are necessarily destroyed, said Pini Youngman, president of TSG, a defense technology company partly owned by Israel Aerospace Industries and the Formula Group. Residual munitions can continue falling due to momentum and gravity, similar to debris from intercepted missiles that descends over wide geographic areas.
Cluster warhead intercepted
“There is nothing new about this weapon. We have known it for many years, long before Iran began launching them,” a Western missile expert told Calcalist.
Because it is impossible to determine while a missile is in flight whether it carries a cluster warhead or a heavy high-explosive payload, Home Front Command maintains a blanket directive for civilians to enter reinforced safe rooms, or public shelters when sirens sound. Experts say a reinforced concrete ceiling — or sheltering beneath two concrete ceilings — generally provides protection from such submunitions.
The wide dispersal pattern often requires Home Front Command to activate air raid sirens across broad areas.
Since the start of the second round of fighting with Iran two and a half weeks ago, the IDF has declined to disclose the number of ballistic missiles launched toward Israel or the interception rates of air defense systems, citing security considerations. That marks a shift from previous rounds of fighting, including in June of last year, when Iran launched about 550 missiles toward Israel and about 85% were intercepted.
Meanwhile, anticipation continues over the deployment of the high-powered laser-based air defense system known as Iron Beam. Developer Rafael Advanced Defense Systems began delivering the system to the air defense array more than three months ago, but defense officials say it remains in the integration phase and is not yet operational.