In an unprecedented move, the Department of Defense announced over the holiday weekend that it would be deploying a Terminal High Altitude Area Defense (THAAD) battery to Israel to assist in defending Israeli airspace against Iranian ballistic missiles. By the time you’re reading this, it’s almost certainly already operational.
The deployment of US air defense systems to an allied country isn’t what’s unprecedented. It isn’t even the deployment to Israel, specifically. THAAD participated in a joint readiness exercise on Nevatim Air Base and later at an undisclosed site in the Negev back in March 2019. And Patriot battalions have regularly rotated through the biannual Juniper Cobra missile defense exercise. What’s different this time is that the United States has never before overtly deployed troops to Israel during an ongoing war. The combat deployment of THAAD marks a significant step in US-Israeli integrated missile defense cooperation, but it is also sending a strategic signal to Iran and other regional actors. While THAAD provides a substantial asset in terms of air defense capabilities, three important takeaways go beyond the technical details and tactical significance.
First, there is a strategic messaging component to the deployment. As proven in the past two missile exchanges between Israel and Iran (to say nothing of the relentless bombardments from Gaza and Lebanon), Israel possesses the most combat-tested and resilient air defense network on the planet. The newly deployed THAAD battery brings an additional AN/TPY-2 to the table. This trailer-sized radar is the most powerful mobile land-based radar in the world, and brings more situational awareness to the integrated network. In terms of interceptor capability, the Israeli long-range Arrow system is roughly equivalent to the THAAD, similarly capable of exoatmospheric interceptions. and is already integrated with Israel’s medium-range David’s Sling and short-range Iron Dome systems. Tactically, THAAD therefore is a buttressing of existing Israeli capabilities, rather than a gamechanger. Strategically, this move is less about bolstering specific Israeli capabilities and more about sending a clear strategic message to Iran and the Middle East more broadly. The presence of THAAD (and more importantly, the accompanying US soldiers) is a visible symbol of American commitment and vital interest in the conflict not spiraling out of control. It was possibly a step the White House agreed to during the October 9 phone call between Israeli Prime Minister Benjamin Netanyahu and US President Joe Biden and is likely aimed at encouraging the Israelis to not rashly strike at vital Iranian nuclear or oil assets in their yet-to-be-launched retaliatory strike. A statement by Netanyahu supports this.
Second, the THAAD deployment expands an already broad network of US air defense assets in the Middle East. The United States already has multiple AN/TPY-2 forward-based radars deployed across the region observing Iran with long-range tracking and surveillance. On top of that, the United States has had an additional THAAD battery deployed in the Middle East, along with supporting Patriot battalions, since October 2023. By deploying a full THAAD battery to Israel itself, the United States is effectively expanding its air defense footprint in Israel with interception capabilities. This complements the AN/TPY-2’s function and enables a more comprehensive detection and interception capacity in the event of an attack. Notably, the United States is also assuming the risk that these American soldiers could end up deliberately targeted, either directly by Iran in the event of another drone or missile attack, or by Iranian proxies who have launched frequent attacks against US forces across the region over the past year.
Finally, the deployment raises the prospect of a permanent THAAD presence in Israel. Historically, THAAD deployments have transformed into permanent stations, as seen with the systems stationed in Guam (since 2013, the author is at left) and South Korea (since 2016). In addition to the political difficulties of removing air defense capabilities once they’re introduced—allies naturally want to maintain the coverage—the complexity of deploying THAAD involves substantial operational support. This is in no small part due to the tremendous power consumption and output of the AN/TPY-2 radar, which makes other tactical radars look like energy-efficient lightbulbs compared to a football stadium floodlight. For comparison, the Patriot’s electrical power plant consists of two 150-kilowatt generators. THAAD requires about ten times that amount, due to the inverse square law. The AN/TPY-2 requires two 1.1-megawatt prime power units, which drink fuel so greedily that it is almost always preferable to connect them into an electrical power grid. This, along with other factors—such as the need for considerable site security—has led to the establishment of permanent installations rather than temporary deployments, excluding exercise rotations like to Romania in 2019.
While these takeaways are meaningful in their own right, they also have implications for Army air defense artillery. Of the seven THAAD batteries available, four are now committed to outside of the continental United States (two in the Middle East, one in South Korea, and one in Guam). Not all the three batteries stateside are in a condition to immediately deploy either, as at least one is being used for flight tests and system upgrades. It is standard for air defense capabilities (including Patriot) to have at least one unit on this type of test mission, where both software and hardware are updated and tested in a constant iterative process. In the words of General Sline in Spies Like Us, “A weapon unused is a useless weapon.” But these deployments also constrain the US Army’s ability to respond to additional contingencies elsewhere given the limited number of systems available for rapid deployment, to say nothing of the increasing strain on the air defense force due to its ever-increasing operational tempo. These are critical factors the Army must account for as it prepares to meet the air and missile defense challenges of the future.
Maj. Peter Mitchell is a strategist, air defense expert, West Point instructor, and Modern War Institute contributor. You can follow him on X @peternmitchell
The views expressed are those of the author and do not reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.
Image credit: Capt. Aaron Smith, US Army