An Integrated, Multilayered Missile Defense Architecture
An effective and credible missile defense architecture includes a number of components, such as an integrated sensor architecture that takes multiple data streams from multiple U.S. and allied or partner sources and creates an integrated command and control and management structure and three different engagement levels: a short-range defense to protect key, high-value nodes in the U.S. homeland and overseas; a ground-based system to give general coverage over North America; and a space-based overlayer that can engage a number of threats across the world, in various stages of flight.
Taken together, such an architecture will increase America’s ability to address adversary threats and strengthen deterrence by denying adversaries the benefit of missile strikes on key targets.
Capabilities. While some of the critical components for an integrated, multilayered missile defense architecture exist today, including regional command-and-control nodes, theater air defense systems, and GBIs, there is important work to be done in (1) integrating disparate systems into a cohesive architecture and (2) expanding existing systems to include more capacities and building capabilities in orbit, in order for the United States to field a credible missile defense architecture.
An Integrated Command and Control. An integrated command-and-control system can more effectively coordinate the tracking and interception of enemy missile launches by developing and fielding a Hypersonic and Ballistic Tracking Space Sensor Layer; and by integrating shots from the various layers, missile defenses can get more shots at incoming missiles, thereby increasing the likelihood of a successful interception. Put another way, if the overlayer misses the interception, GBIs have the opportunity to engage the incoming target. If the GBIs miss, the underlayer can have some utility in potentially intercepting inbound missiles or warheads at a limited number of critical sites.
An Effective Underlayer for Protecting Critical Sites. As noted in a recent study, current off-the-shelf missile defenses, such as Patriot PAC-3s, Aegis Afloat, air-to-air missiles and surface-to-air missiles, directed-energy weapons (DEW), and THAAD systems, can provide robust missile and autonomous systems defenses around a limited number of key locations within the U.S. homeland, at forward bases, and at key allied locations.
By putting such systems near key bases, ports of embarkation, and command-and-control nodes, defenses have multiple interception opportunities of enemy missiles which target critical, high-value nodes. Accordingly, the United States will develop and deploy an underlayer that leverages terminal phase intercept capabilities that are postured to defeat a countervalue attack.
Ground-Based Layer. The current missile defense layer comprises 44 ground GBIs at sites in Alaska and California. They are optimized for targets coming from North Korea and were built when North Korea had a very modest ability to target North America with missiles. Later this decade, the next-generation interceptors (NGIs) will augment the existing GBIs on the West Coast with 20 additional interceptors.
The fielding of NGIs is a necessary step, but one that is inadequate for the current threat. A modest expansion of missile interceptors is necessary to contain not only the expanding North Korean and Iranian missile threats but also threats posed by Russia and China. To that end, the United States will expand the number of NGIs it purchases from 44 to roughly 64 and look to station a significant portion of the new interceptors on a new missile defense site on the East Coast to better target incoming adversary missiles from Eurasia. These 64 NGIs should replace the older GBIs currently deployed in Alaska and California.
These capabilities, needed today, given the growing threat from adversary long-range fires, are an important, interim step to a more robust, space-based missile defense layer.
A Space-Based Overlayer. The “overlayer” is a capability that will field a network of microsatellites in orbit that would serve as both sensors and communication relays, as well as platforms for launching interceptors capable of destroying long-range threats, regardless of point of origin, destination, or delivery mechanism. Of particular utility against rogue states, such as Iran and North Korea, an overlayer will make an important contribution on threats posed by China and Russia.
The constellation’s networked sensors automatically will share launch and targeting data with each other and with ground-based command-and-control networks. They will carry small kinetic, non-explosive kill vehicles or directed-energy weapons that can engage targets across multiple stages of flight, including the boost phase, midcourse flight, or coasting phase.
The technology to share launch and targeting data among the orbital sensors exists today. Similar to how ride-share applications use networked artificial intelligence (AI) to identify which vehicles are closest to a customer’s location, networked satellites can identify a threat and identify which interceptors are best positioned to engage and destroy an enemy’s launched missile.
A constellation of satellites in orbit through the development and deployment of a Proliferated Warfighter Space Architecture can engage enemy missiles far sooner than a ground-based system, particularly those that are located thousands of miles away in North America. Because they are closer to the target in mass, they can get not only multiple shots at enemy missiles during their trajectory, but the satellites can engage some targets while the targets are still in their ascent phase—thereby increasing the chances that interceptors may destroy inbound targets.
In addition, an orbital sensor and engagement capability addresses many of the challenges posed by terrestrial-based engagement, particularly its ability to surveil huge portions of the Earth’s surface from orbit. This expanded sensor coverage, coupled with redundant interceptors, increases the likelihood of a successful interception before the missile strikes its intended target.
A proliferated constellation of orbital satellites will address a variety of terrestrial or space-based threats. Further, a robust space-launched resupply capability that leverages commercial launch capabilities would be able to replace expended satellites quickly during a conflict, thus strengthening the resilience (and therefore, efficacy) of such a capability. Building such satellites at scale enables cost-efficiency, resilience, and rapid reconstitution.
Allied and Theater Missile Defenses. The United States will strengthen its homeland defenses while at the same time strengthening missile defenses for forward deployed U.S. forces and with allies and partners against missile threats from any adversary. By strengthening, integrating with, and operating with allied and partner missile defense systems, the United States can better deter and, if necessary, defeat missile and autonomous systems threats globally, thereby reducing risk to deployed American forces, the lives and citizenry of America’s allies and partners, and, ultimately, the American homeland.
Indeed, adversary missile and autonomous systems threats increasingly blur the line between theater or regional missile threats and missile threats to the American homeland. To combat such threats, regional Combatant Commanders will work with key allies and partners in the Indo–Pacific, Europe, and the Middle East on information sharing (both pre-launch and post-launch), targeting data, and interceptions. Indeed, Iran’s 2024 attacks on Israel—which mixed ballistic missiles, cruise missiles, and autonomous systems—failed due to the integration of American and partnered missile defense capabilities and command-and-control nodes. This type of collaboration will be a model for successful capability integration among American, allied, and partner missile defense architectures. Indeed, cooperation with like-minded allies and partners will be crucial both for real-world interceptions, but also, increasingly, on development of ever-more advanced and capable missile defense systems.
Such advances will be crucial to counter adversary anti-access/area-denial (A2AD) strategies that increasingly rely on advanced missile threats to deny American access to forward theaters. Indeed, collaborating with allies and partners on building and deploying advanced missile interceptors, both at home and abroad, will enable American freedom of action and key access to the most critical parts of the globe. Regional missile defense architectures in the Western Pacific, including national missile defenses in Japan and South Korea, NATO missile defense architectures, and the effective missile defense systems increasingly employed by U.S. partners in the Middle East, only strengthen America’s position, standing, and freedom of action.
Where appropriate and feasible, the United States will work with allies and partners on IAMD detection and defeat capabilities that can be concealed or disguised to enhance deterrence and complicate adversary targeting.
An Ever-Evolving Architecture. In addition to the above layers, designed to prevent adversaries from launching a long-range strike on the United States or its regional allies, the United States will continue to develop new capabilities with an eye toward not only strengthening defenses, but to introduce uncertainty into the minds of its adversaries. To that end, not only will the Defense Department continue to explore new capabilities, but it will employ existing capabilities in innovative ways. For instance, placing missiles on autonomous aerial systems and on drones to shoot down enemy missiles in the boost phase, or placing missile interceptors, such as the SM-6, into shipping containers in overseas ports that could target enemy missiles close to their homelands, would not only help to protect key areas, but would keep America’s adversaries guessing. To this end, the Defense Department will embark upon an aggressive campaign to identify key capabilities that can mitigate the adversary missile threat today.
Implementation. Within one year of the publication of this draft MDR, the Defense Department will consult with allies and partners in East Asia, Europe, and the Middle East on the incorporation of existing national and theater defense systems into the integrated, multilayered missile defense architecture. Such consultations will identify avenues for data sharing, operational integration, and future advancements. Within one year, the Secretary of Defense will brief Congress on a four-year plan to (1) integrate existing missile defense architectures around the world; (2) establish a third, East Coast missile defense site; and (3) field an initial operating capability for a space-based layer, to include sensors and shooters, all by January 1, 2029. Further, the United States will field a robust, resilient, and credible fully operational space-based missile defense layer no later than January 1, 2032.
