What’s THAAD missile shield US has deployed in Israel and how it works

The US has announced it will deploy troops to Israel along with the Terminal High Altitude Area Defence (THAAD), its most advanced missile defence system.

THAAD is meant to bolster Israel’s multi-tiered air defence systems against mainly Iranian ballistic missiles as the US involvement in Tel Aviv’s year-long war on Gaza becomes increasingly direct and ostensible.

On Tuesday, the US said components of the missile system have “started arriving” in Israel and will become operational in the “near future”.

The decision to deploy THAAD was taken after Israel’s three-layered air defence system—said to be the “most effective, most-tested missile shield the world has ever seen”—failed to intercept a barrage of 180 ballistic missiles that Iran fired at the Zionist state on October 1.

That was the third—and the largest—ballistic missile attack on Israel that its much-vaunted air defence system failed to intercept in one year.

Earlier, its saturation resulted in the failure to intercept a rocket barrage from Hamas in the surprise attack on October 7, 2023. Israel’s air defence systems were again overwhelmed on April 15 when Iran launched a missile attack against Tel Aviv.

Even though the Israeli air defence systems have also been developed by US arms manufacturers, THAAD is different in terms of design, range and deployability.

Here’s a quick look at how THAAD operates and what sets it apart from the Israeli air defence systems already in place.

What is THAAD?

THAAD is designed to intercept medium- to long-range ballistic missiles during their terminal phase of flight. The air defence system gets in motion when the oncoming projectile re-enters the atmosphere and begins its dive towards the target.

According to the Congressional Research Service, the US Army currently has only seven THAAD batteries. Each battery consists of six truck-mounted launchers and is operated by 95 soldiers.

These launchers carry eight interceptors each. Other main parts of the battery include one radar and one tactical fire control component.

THAAD was developed by US arms maker Lockheed Martin Corporation, which also supplies Israel with F-16 and F-35 fighter jets that have been used “extensively” to bomb Gaza.

Two of the seven THAAD batteries are currently deployed in South Korea and Guam, a US island territory in the Western Pacific.

In October 2023, the US deployed one THAAD battery in the Middle East to protect Israel as it started bombing Gaza.

Lockheed Martin received a contract of $74 million in 2022 to produce the eighth THAAD battery, which is expected to be fielded by 2025.

The US military budget for the current fiscal year includes a request for $732 million to continue the development of the THAAD system to address the “current and evolving threat” and make improvements to counter “more advanced threats”.

The US is not the only country that owns THAAD batteries. Under the foreign military sales programme, Lockheed Martin has already sold two THAAD batteries to the United Arab Emirates.

The UAE used THAAD to foil a Houthi ballistic missile attack in January 2022, marking the first-ever operational intercept in a combat environment by any country.

Saudi Arabia also expects the delivery of seven THAAD batteries and supporting equipment, according to the Congressional Research Service.

How Israeli air defence systems work

Israel has a three-tier air defence system. The first or bottom tier is the most talked about Iron Dome, which intercepts short-range, surface-to-surface rockets of up to 70-kilometre range.

David’s Sling is the middle tier that intercepts medium-range missiles of up to 300 kilometres.

The third tier consists of Arrow 2 and Arrow 3 defence systems that intercept medium- and long-range missiles of up to 2,000 kilometres.

Several “batteries” of air defence systems deployed around big cities help Israel detect any projectile before it enters its air space.

Based on the trajectory of an incoming rocket, the system quickly estimates the precise impact location. If the anticipated site of impact is far from populated areas or military installations, the system lets the rocket land without interception.

Otherwise, the air defence system quickly fires an “interceptor missile” aimed at pulverising the moving rocket before it can land inside Israel.

What makes THAAD different?

Israel’s air defence mechanism against missiles and rockets is considered one of the best, but it struggles to detect slower-moving unmanned aircraft.

For example, a drone strike by Lebanon-based Hezbollah breached the Israeli air defence systems on Monday, killing four Israeli soldiers and injuring 58 others at an army base.

It was the latest attack in a string of recent drone strikes that highlighted the “weaknesses in the way that Israel detects” drones.

Another difference between the two systems is the operational altitude and range. THAAD can intercept targets at distances up to 200 kilometres. As for the altitude, it can operate at exo-atmospheric altitudes, engaging ballistic missiles at a height of up to 150 kilometres.

This allows THAAD to neutralise ballistic missiles in the short range (up to 1,000 km), medium range (1,000-3,000 kilometres), and intermediate range (3,000-5,000 km) during their final phase of flight.

In contrast, the comparable tiers of Israeli air defence systems—David’s Sling, Arrow 2 and Arrow 3—are supposed to intercept ballistic missiles of up to 2,000 kilometres.

THAAD and Israeli systems also use different interception technologies. The US system relies on a “hit-to-kill technology”, which means it destroys the oncoming ballistic missile by direct impact.

The hit-to-kill technology relies on the kinetic energy of the collision as THAAD interceptors do not carry any warheads.

In contrast, Israel’s Iron Dome uses a proximity-fused warhead, which detonates near the target to destroy it.

David’s Sling deploys the same technology used by THAAD for its interceptors while some variants of Arrow rely on a fragmentation warhead, which explodes into a mass of metal fragments.

The ease of deployment and mobility is another feature that sets THAAD apart from its Israeli counterparts. THAAD is highly mobile and can be quickly deployed by US Air Force cargo aircraft like C-17 and C-5.

However, both David’s Sling and Arrow are relatively difficult to redeploy quickly because of the complexity of their radars and launch systems.