North Korea’s test of an unprecedented number of ballistic missiles in 2022, including several types of intercontinental ballistic missiles, is the latest reminder the United States faces an increasingly perilous security environment.
U.S. adversaries continue integrating offensive missiles into their strategies to support coercion, intimidation and aggressive military behavior. While it might be tempting for the United States to throw up its hands and allocate missile defense resources elsewhere in this increasingly unpredictable missile threat environment, the U.S. should instead continue to strengthen its capabilities for effective homeland defense.
Today, the nation is defended against a limited ICBM attack on the homeland posed by the missile arsenals of “rogue states” such as North Korea and Iran (who is also continuing its pursuit of longer-range missiles and a nuclear capability). In response to North Korean and Iranian efforts, the United States is considering how to improve its missile defenses to deter possibly larger and more sophisticated missile attacks and, if deterrence fails, to reliably protect the homeland against missile attacks.
At the same time, these developments have raised concerns an increase in the scale or complexity of the North Korean missile threat may eventually overwhelm the ability of the Ground-based Midcourse Defense system to defend against most or all of these threats. This possibility calls into question the broader strategic value of improving, or even maintaining, the nation’s missile defenses.
An argument in favor of scaling back missile defense development too readily discounts the role defenses play in U.S. deterrence and defense policy — even in the context of an expanding missile threat. Moreover, it leads to an erroneous “all or nothing” approach to defending the United States against significant dangers.
At least four crucial considerations help make the case for sustaining and strengthening the homeland missile defense posture.
The first is uncertainty around how the threat will evolve over the next decade. While North Korea is committed to its ICBM program, the projected size of its arsenal and timing remain uncertain.
North Korea has encountered technical and developmental setbacks in its ICBM program that not only affect the pace of this threat, but also raise questions about the operational reliability of such complex weapon systems — at least for the foreseeable future.
Second, defenses do not have to be large or perfect to inject complexity and doubt into the adversary’s pre-war planning and execution of missile strikes. Even limited defenses are capable of weakening an opponent’s confidence in its ability to achieve its military objectives.
Third, even in the face of possible advances in rogue state long-range missiles, missile defenses provide significant value to blunt blackmail or coercion where the adversary seeks to test American political will — especially by threatening limited strikes. In these circumstances, defenses would confront the aggressor with the prospect its attack would be futile, while risking a devastating U.S. counterattack.
Fourth, it is dangerously imprudent to rule out the possibility deterrence might fail. Crises have unpredictable dynamics fraught with misperception and miscalculation. There will also be situations in which deterrence may be simply irrelevant, particularly in those instances where an adversary’s ruler believes he has nothing to lose in launching his ICBMs. Under these conditions, defenses remain vital to reducing the scale of destruction in the United States.
The Department of Defense’s 2023 budget request takes a number of steps to align the homeland missile defense posture with increasingly challenging missile threats. It maintains the bipartisan focus on sustaining and enhancing the current GMD system while funding modernization efforts to ensure it can effectively counter larger and more sophisticated rogue state ICBM threats.
This includes developing a new Next Generation Interceptor expected to add 20 defensive interceptors and potentially replace the 44 existing GBIs by the end of the decade. The budget also funds a network of space- and land-based sensors crucial to tracking and targeting more advanced ballistic and hypersonic missile threats.
Collectively, these efforts to build a second-generation homeland defense system begin laying a foundation to address more capable North Korean and Iranian missile threats. However, it is essential for the Biden administration and Congress to not only sustain current modernization efforts but also define a clear strategy for the next generation of missile defense concepts, technologies and capabilities.
Directed-energy weapons, like high-powered microwave systems and kinetic interceptors deployed on airborne platforms for boost phase engagement, hold considerable promise for more effective intercept capability at lower cost. Progress in the commercial satellite sector over the last decade has produced more capable, smaller and cheaper platforms and offers innovative opportunities for advanced military space-based sensors to defend against more complex missile threats.
While the United States may not be able to eliminate all rogue state ICBM risks over time, that does not mean it should turn away from missile defense. The United States can reduce these risks by investing in emerging and disruptive technologies to improve the capabilities of effective missile defenses while continuing to offer significant deterrence and, should deterrence fail, a way to limit damage.
Peppi DeBiaso is the former director of the Department of Defense’s Office of Missile Defense Policy and a nonresident senior associate at the Center for Strategic and International Studies.
