A Longer-Term Approach

The recommendations described above build on either existing programs or plans examined by DoD in recent years and, if funded, offer an expedient path to shore up homeland missile defense. However, these steps alone are insufficient to frustrate Moscow and Beijing’s ability to wield coercive nuclear threats. To cope with this challenge requires a pivot in our approach to more innovative missile defense capabilities, technologies, and investments.

The foundation for any defense responsive to advances in offensive missile threats begins with sensors, especially those based in space. It is the only domain that offers persistent and global tracking of missiles from launch until they reenter the earth’s atmosphere. There are initial efforts to move in this direction. For example, the U.S. Space Force and the Missile Defense Agency are developing complementary space systems intended to provide precision tracking data of enemy missiles, including hypersonic weapons, that will be fed to defensive interceptors to allow them to destroy incoming warheads. Additionally, the U.S. must move forward with a more robust R&D program to develop a discrimination space sensor that can distinguish real warheads from possible decoys. This advancement should cut down on the number of interceptors needed to destroy a threat missile—a huge game changer for the defense. Space sensor discrimination efforts over the past decade have suffered from anemic funding and an unwillingness to treat discrimination as an essential missile defense mission. Both the precision tracking and discrimination space efforts should be prioritized and adequately funded as crucial elements of a more comprehensive layered defense.

Equally important, Washington must think more broadly about a framework for missile defense that incorporates a mix of interceptor systems and technologies operating in different domains—land, sea, air, and space. This consideration is central if the United States is to achieve the benefits of layering discussed above.

Currently, the DoD's effort to modernize the homeland defense posture is centered on developing a singular new land-based interceptor—the Next Generation Interceptor. The plan is to have approximately twenty fielded by the early 2030s, though this number could be increased depending on the progress of more advanced systems. However, the new ground-based interceptor should be viewed as a “bridging” measure to transition to a defense architecture that incorporates multiple layers containing a mix of interceptors that will be required to cope with both larger future rogue state missile salvos as well as limited nuclear missile launches from Russia and China.

Emerging Capabilities and Technologies

There are several areas of new and emerging technologies that can offer a foundation for the next generation of missile defense.

For example, within a layered defense framework, one potentially high-payoff approach is to intercept the missile while it is “boosting” into space, thereby destroying the missile, warhead, and any countermeasures it may be carrying early in flight. Progress has been made over the past decade in critical areas such as unmanned aerial vehicle platforms that make the boost-phase layer more attractive than in the past.

There is a new generation of unmanned aerial vehicles with the ability to operate with extended range and endurance across multiple regions and at altitudes beyond the reach of enemy air defenses. At the same time, advances are occurring in high-speed hypersonic missile technology (for both offensive and defensive roles) that could play a role in countering missiles in the boost phase. For example, the Army and Navy are testing new long-range offensive hypersonic missiles, while the Missile Defense Agency and Defense Advanced Research Projects Agency (DARPA) have been conducting technology development efforts for defensive hypersonic interceptors. The innovative application of unmanned platforms combined with long-range hypersonic interceptors offers one possibility for a new layer of defense capable of reducing the number of adversary launches during the boost phase, especially against countries that lack geographic “strategic depth,” such as North Korea and Iran.

High-energy compact lasers for air and cruise missile defense of the homeland are another area where advances are being made. All three Services are developing mobile high-energy lasers to shoot down cruise missiles and other air-breathing weapons. The Army, for example, is testing a 300-kilowatt-range, ground-based laser system on mobile platforms, while DoD is in the early stages of developing a 500-kilowatt laser that may drive the technology base toward more powerful lasers in the megawatt class needed to knock down incoming ballistic missiles in the future.

A third area that should receive greater attention is space-based defense. Over the next decade, the development of space-based defenses may provide the most promising path to achieving a mix of effective interceptors as part of a multi-layered defense to defeat missile strikes from one or more adversaries. Much has changed since the United States last examined space-based defenses. For example, marked progress has been made in crucial areas underpinning space-based kinetic energy interceptors, including precise sensor tracking, micro-processing capability, space communication networks, miniaturization of satellite components, artificial intelligence to support the command and control of large satellite constellations, and substantially reduced space launch costs. Many of these technologies are already operating today in the commercial space sector. To better assess the current state of SBI-relevant technology, the DoD is required to perform detailed architectural trade and cost studies and carry out R&D efforts to enhance the maturity of various SBI systems.

The Policy Decision

Objectors would argue that a shift in U.S. policy in this direction will either cost too much, stoke a new round of the arms race, or both.

What we lay out is affordable. Today, the MDA spends about 30 percent (~$3.5 billion) of its annual Missile Defense Agency budget in direct support of homeland missile defense. This is less than a third of one percent of the Department of Defense FY25 budget request of $850 billion. Resourcing the activities mentioned above would amount to less than one percent of DoD’s budget or about $8 billion per year. The additional $5 billion per year should be weighted towards the research and development necessary to move to next-generation capabilities, with the balance apportioned to rectifying the most pressing shortfalls in the current ground-based missile defense system.

As to whether expanding U.S. missile defenses would stimulate further growth in Russia and China’s nuclear arms, a broader perspective is necessary. U.S. restraint in missile defense—it has chosen to deploy only forty-four interceptors over the past twenty years—has failed to produce any reciprocal restraint on the part of Moscow and Beijing’s strategic arms programs, which continue to increase in size and quality. Furthermore, it is not without a measure of hypocrisy that both Russia and China have well-established strategic air and missile defense programs and capabilities, presumably to blunt U.S. missile launches against their respective homelands. Russia currently has more ground-based interceptors deployed to protect its homeland—sixty-eight nuclear-tipped interceptors—than the United States. The recommendations for U.S. missile defense outlined above do nothing more than acknowledge the importance of protecting the homeland against limited threats, a position long understood by Russia and, more recently, China. Even if Russia and China choose to respond to improved and expanded U.S. homeland missile defenses, not a given historically, the net benefit to U.S. security of countering their coercive strategies far outweighs any additional missiles they would procure.

North Korea, Russia, and China—and perhaps soon Iran—will continue to grow their long-range missile capabilities with the intent to hold the U.S. homeland at risk. The next president has no time to waste. Fortunately, there is no need to repeat the extensive missile defense reviews already conducted by the Trump and Biden-Harris administrations, which unequivocally establish the indispensable roles of missile defense in U.S. national security. Instead, the president should take early action to bolster U.S. homeland missile defense by issuing clear direction to their national security team to bring forward within 120 days a set of options for a more comprehensive, layered missile defense plan to defend the American people against the threat of nuclear missile attack.

Dr. Peppino A. DeBiaso served in a number of positions in DoD, including as the Director of the Office of Missile Defense Policy and as the Deputy Director for Strategy, Forces, and Operations. He is an Adjunct Professor at Missouri State University's Defense and Strategic Studies Graduate School in Fairfax, Virginia, and a Senior Associate (non-resident) at the Center for Strategic and International Studies in Washington, DC.

Dr. Robert M. Soofer served as Deputy Assistant Secretary of Defense for Nuclear and Missile Defense Policy from 2017 to 2021. He was a professional staff member on the Strategic Forces Subcommittee of the U.S. Senate Armed Services Committee. He is now a senior fellow with the Atlantic Council’s Scowcroft Center for Strategy and Security and an adjunct associate professor at Georgetown University’s Security Studies Program.

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