The US Will Build an Iron Dome Air Defense System

Note: The US does not have a fully integrated air defense system for the continental United States. And it does not yet have a system that can intercept the emerging threat of hypersonic ballistic missiles and delivery systems including hypersonic glide vehicles. The current hodge-podge of US ballistic missile defenses is, therefore, not necessarily a good model to meet President Trump’s goal of an Iron Dome for America.

The US has almost no full time air defense on the East Coast, nothing in the center of the United States, and nothing along the Caribbean Sea.

Newly approved Secretary of Defense Pete Hegseth has announced that President Trump will issue a number of Executive Orders for US Defense, including the creation of an Iron Dome system “like the one used by Israel to deflect incoming missiles.” With hypersonic threats starting to multiply, the old mutually assured destruction (MAD) doctrine will no longer work to prevent a first strike, and the US could be subjected to devastating and fatal nuclear ballistic missile attack.

It is important to distinguish between what Israel calls Iron Dome and what President Trump has in mind.

In Israel Iron Dome (Kippat Barzel) refers to the air defense system that was developed initially to deal with short range missiles fired into Israeli territory from Gaza.

In President Trump’s usage, Iron Dome refers to an integrated air defense system that can protect the United States from missile attack.

Today Israel has an integrated air defense system that includes Iron Dome, Iron Beam, David’s Sling, Arrow 2 and Arrow 3 plus long range radars. Israel’s system includes a capability to intercept ballistic missiles in the exoatmosphere and, possibly, beyond. Israel is also working on a new version of the Arrow system in partnership with the US, called Arrow 4. (Israel air defenses have also been integrated with US radars.)

The Israeli air defense shield was partly US funded and major US defense companies, Raytheon (now RTX Corporation), Boeing and Lockheed participate in Israel’s air defense programs. RTX also markets SkyHunter, a variant of the Tamir interceptor used in Iron Dome. RTX is building a new facility in Camden, Arkansas to produce SkyHunter for the US Marines. “The Marine Corps’ FY-25 budget request includes $111 million for the program to support the purchase of 12 launchers and 242 missiles as it transitions from rapid prototyping to rapid fielding.” The new facility is partly owned by Rafael Advanced Defense Systems, the Israeli company that manufactures Iron Dome.

At the top level of US-Israel air defense cooperation is the partnership between the US Missile Defense Agency (MDA) and Israel Missile Defense Organization (IMDO). The IMDO is part of the Israeli Directorate of Defense Research and Development (DDR&D), at Israel’s Ministry of Defense. The MDA is a research, development, and acquisition agency that works on ballistic missile defense systems for the United States and its allies.

Among allied countries, the US is among the least prepared to counteract enemy ballistic missiles and other threats including drones. The lack of protection was intentional as the opponents of missile defenses, including those opposing President Ronald Reagan’s Strategic Defense Initiative (SDI) argued that achieving a missile shield was neither technically feasible nor strategically acceptable.

The technical arguments in the mid to late 1980’s centered on the challenge of putting interceptor systems in space (one of the Reagan proposals was called Brilliant Pebbles, an idea pioneered by Lowell Wood and Edward Teller at the Lawrence Livermore National Laboratory).

The policy argument claimed that SDI would undermine the MAD doctrine. MAD stands for Mutually Assured Destruction and it is based on the notion that neither the US or its adversaries would use nuclear weapons since the outcome of their use would be the assured destruction of the contending party. Arms control agreements were tailored around the idea of blocking any breakthrough that would give either the US or the USSR (and its successor, Russia) a way to achieve a credible first strike capability (meaning that the nuclear assets of the other side would be obliterated before they could be used for retaliation).

While some claimed that MAD was an acceptable approach to safeguard against the use of nuclear weapons, others, including President Reagan, saw MAD as a mutual suicide pact. A key problem was that one country, China, did not participate in arms control agreements and continued to grow its nuclear strike capabilities. Another was the rise of additional nuclear actors, notably North Korea and others seeking to join them such as Iran.

The US put in place an air defense system based in Greely Alaska and Vandenberg Space Force base in California called the Ground Based Interceptor (GBI) which is part of the US Ground Based Midcourse Defense System. That multibillion dollar system has been plagued by numerous problems and a renewed effort is now underway to upgrade the interceptor kill vehicles and field a $17 billion Next Generation Interceptor for GBI. An Interim Solution of 20 interceptors is planned for 2026.

It is claimed, without any real proof other than the limited number of interceptors, 44, associated with GBI, that GBI was mostly focused on a rogue state threat (that is North Korea) and not China.

GBI uses a hit to kill intercept system, meaning that an incoming ballistic missile warhead is destroyed by the kinetic force of a non-explosive kill vehicle that is part of the interceptor. Called an EKV for Exoatmospheric Kill Vehicle, it has been a source of problems and is limited in dealing with maneuvering nuclear warheads. A plan to redesign the kill vehicle, called RKV, was dropped after the plan was judged unworkable. Beyond the kill vehicle, a huge issue, radars associated with GBI also have had problems, particularly a radar known as Sea Based X Band. X Band radars operate in the 8 to 12 GHz microwave band.

The Defense Department apparently has plans to put an evolved GBI system on the East Coast. At least four locations are under consideration, but the most likely is Fort Drum in New York near Lake Ontario. Congress has mandated an East Coast system to be in place by 2030, although without a workable system and funding, the 2030 date is optimistic.

The US also has forward deployed THAAD (Terminal High Altitude Air Defense) systems; in Korea, UAE, Israel, Romania and Guam. THAAD is mainly an area defense system, and it has been used once, successfully, intercepting a Houthi-launched ballistic missile. That THAAD unit was operating from Israel. THAAD has a range of 150 to 200 kilometers (93 to 124 miles).

In addition, the US has AEGIS air defense systems on board US Arleigh Burke class destroyers (DDG-51) and Ticonderoga cruisers (CG-47). AEGIS is regarded as effective against ballistic missiles. There are around 56 AEGIS-equipped ships, although the US Navy is retiring some Ticonderoga-class cruisers.

The US also has three AEGIS-Ashore (land based) systems, one in Guam, another in Poland and in Romania. AEGIS-Ashore was also planned for Japan, but the Japanese government cancelled the program, allegedly because of local opposition to interceptor sites near them. Japanese Kongō class ships do have the AEGIS system, but there are only four ships. Two new Kongo-class ships are planned over the next few years. In addition, Japan and the US are working on an interceptor optimized to intercept hypersonic threats.

AEGIS has been used in the Red Sea to counter Houthi missiles. A key problem has been intercepting Houthi-fired anti-ship ballistic missiles. Software in the AEGIS system was hurriedly upgraded to account for the anti-ship missile threat, and AEGIS has played a role in helping track threats and destroying Houthi missiles. As of January, US ships have fired 120 SM-2 missiles, 80 SM-6 missiles, 160 rounds from destroyers and cruisers’ five-inch main guns, as well as a combined 20 Evolved Sea Sparrow Missiles (ESSM) and SM-3 missiles. SM-2, SM-3 and SM-6 are AEGIS missiles. In one case the USS Gravely had to rely on its Phalanx CIWS rapid fire short range gun to knock out a Houthi missile that was tracked by the AEGIS system’s radar.

AEGIS is important for US missile defense in the Pacific and Atlantic and now in the Red Sea and Persian Gulf.

New Types of Threats

The US does not have a fully integrated air defense system for the continental United States. And it does not yet have a system that can intercept the emerging threat of hypersonic ballistic missiles and delivery systems including hypersonic glide vehicles. The current hodge-podge of US ballistic missile defenses is, therefore, not necessarily a good model to meet President Trump’s goal of an Iron Dome for America.

The US has almost no full time air defense on the East Coast, nothing in the center of the United States, and nothing along the Caribbean Sea.

The US does have some important components for a US Iron Dome. Among these components are highly advanced radars, hit to kill technology, sophisticated secure communications, space based sensors, and experience it can draw on from its deployments in the Middle East and Israeli know-how and experience dealing with enemy swarm tactics.

One can expect that the Russians and Chinese will continue to pursue hypersonic platforms including Russian systems such as Avangard and Chinese hypersonic threats. China already has “the world’s leading hypersonic arsenal” according to the US Defense Intelligence Agency. The use by Russia in Ukraine of the Oreshnik intermediate range ballistic missile featuring a Avangard-like hypersonic glide vehicle with multiple kinetic warheads demonstrates that missile defenses will be challenged not only by nuclear, but by conventionally armed missiles too.

An Iron Dome for the United States, therefore, needs to account for both conventional and nuclear threats, for hypersonic weapons, and for serious problems of detecting and destroying the threats efficiently and effectively.

For long range ballistic missile threats this means the US should look again at Brilliant Pebbles and other space-based intercept capabilities. A space based approach is a more certain way of knocking out hypersonic glide vehicles before they are launched by ballistic missiles.

For intermediate and short range threats the US needs to improve its ability to destroy incoming threats at the theater level, whether on land or sea. It may be possible to build on AEGIS and other systems for this purpose, linking land based radars to improved space-based sensors and developing hypersonic interceptors.

The US also needs to step up work on air defense integration and the use of artificial intelligence to deal with increasingly sophisticated tactics including different types of decoys and maneuvering warheads. AI if properly developed may also be able to distinguish between a conventional and nuclear threat.

A US Iron Dome is a huge challenge but it is needed and indispensable before one of our adversaries concludes destroying the US can easily be accomplished. That’s the risk of sticking with MAD, and it is the reason that both Secretary Hegseth and President Trump are moving quickly to build a US Iron Dome.