The Pentagon has confirmed it’s deploying a high-altitude missile defense system, operated by U.S. troops, to Israel. This Terminal High-Altitude Area Defense (THAAD) system will bolster Israel’s defenses following Iran’s recent missile attack. It will also provide the U.S. with an opportunity to test THAAD against real-world threats. THAAD is expected to enhance Israel’s existing missile defense layers, which include Arrow 3, David’s Sling, and U.S. Navy ships equipped with SM-3 and SM-6.
THAAD’s interceptor reportedly relies on a kinetic strike, using physical force to destroy its target. Without the atmosphere of space, explosive energy needs a carrier, like shrapnel, to disrupt the ballistic warhead. Shrapnel adds mass, limiting maneuverability, range, and intercept speed. Even with shrapnel, the timing must be precise for the expanding field to intercept the warhead. The warhead’s heat-resistant armor might also withstand a small impact. Given the precision required and simple ballistic trajectories, a kinetic kill vehicle is considered the most effective intercept method.
While THAAD can detect aircraft, it’s not generally used to engage them. Its interceptor’s speed makes an explosive warhead unnecessary. Thrusters are used for maneuvering during the initial boost phase. Like PATRIOT, THAAD can track incoming missiles, even through debris or while attached to the fuel tank. The radar guides the missile, and the missile provides updates on its target.
There’s also a political aspect to this deployment. A kinetic kill missile, without a warhead, is more easily positioned near adversaries under the guise of defense. This might reduce concerns about offensive use in a first strike. The USSR’s concerns about Pershing missiles led to the INF treaty, banning intermediate-range ballistic missiles. THAAD’s lack of a warhead likely exempted it from this ban. While the Tomahawk is an intermediate-range cruise missile, the U.S. only tested a land-based version in 2019.