How Expensive Missile Defense Can Make the U.S. Less Safe

(Bloomberg Opinion) -- It isn’t often that a president visits the Pentagon to unveil a wonkish strategy document. Yet that is what Donald Trump did last week when he presided over the long-delayed rollout of the U.S. Missile Defense Review. Notwithstanding some Trumpian bombast, the review is basically a mainstream document that fits squarely within the tradition of U.S. nuclear strategy. It accurately depicts a world in which advanced missile technology has proliferated and the U.S. has become more vulnerable.

The real value of such documents, however, lies in their recommendations, and here the results are more mixed. In dealing with rogue states such as North Korea, those recommendations are fairly sensible. Yet the vast buildup in missile-defense capabilities it advocates will also have major implications for U.S. relations with Russia and China, raising harder questions about whether the benefits are worth the expense.

The basic message of the review is simple: The strategic environment has deteriorated badly.

Iran has expanded its short- and medium-range missile capabilities. North Korea has made great progress with its intermediate-range missiles and nascent intercontinental ballistic missile program. China and Russia have modernized their arsenals and are developing hypersonic glide vehicles and other advanced delivery systems. China, especially, has fielded short- and intermediate-range missiles that threaten U.S. bases and forces abroad.

The U.S. must therefore improve its missile-defense capabilities across the board. This means expanding today’s primary system: the ground-based, mid-course defense systems now in Alaska and California to protect against ICBMs. It also means strengthening forward-stationed missile defenses in Europe, the Middle East and East Asia, and developing “boost-phase” defenses that can knock down ballistic missiles shortly after launch.

The review also calls for building new kill vehicles that can better deal with decoy warheads; developing a space-based layer of sensors; and investing in lasers that may eventually offer a more cost-effective defense. Not least, it emphasizes taking the offensive, through precision-strike capabilities that can disable missiles before they are launched.

The goal, in theory, is a “layered defense” that will protect the U.S. homeland, forces abroad and — vitally — allies, while also sustaining America’s ability to project military power. The practical issue is the cost of developing and fielding all these of capabilities, which could run into the hundreds of billions of dollars.

The review also reflects discomfort with the idea of mutual-assured destruction — the theory that the best safeguard against nuclear war is a situation in which no combatant nation would survive. Dating back to the Cold War, the U.S. has attempted to limit its vulnerability by devising strategies meant to cripple an adversary’s nuclear force before it can get off the ground, or to intercept parts of that force once they are airborne. By emphasizing the need to eliminate enemy missile forces both before and after launch, the review is part of that longer tradition.

For all the criticism the review has received from the arms control community, improved U.S. missile defenses are probably the price of peace on the Korean Peninsula. For some time, it has seemed likely that Washington will have to live with a nuclear-armed, ICBM-wielding North Korea, because the consequences of forcibly depriving Pyongyang of that capability are simply too ghastly. Yet deterrence will only be a palatable option for U.S. leaders if they take steps to mitigate nuclear vulnerability from one of the most bellicose regimes on earth.

It remains uncertain whether existing or even expanded missile defenses could actually defeat, say, five to 10 North Korean intercontinental ballistic missiles. But enhanced mid-course defenses, combined with a boost-phase program and “left of launch” measures meant to destroy or cripple enemy missiles on the launch pad could provide some protection — and make Kim Jong Un question whether his arsenal would actually get through.

North Korea is not the only rival affected by U.S. missile defenses, however, and here the situation gets stickier. Systems to counter the North Korea threat can be adapted for those posed by Chinese and Russian missiles. And while the review is principally concerned with the ballistic-missile threats posed by rogue states, its emphasis on defending against cruise missiles and hypersonic weapons is clearly aimed at great powers. Officials in Moscow and Beijing have long worried that U.S. missile defenses are actually meant to hamper their own nuclear arsenals — and perhaps even enable Washington to launch a nuclear first strike.

U.S. missile defenses have never been robust enough to provide real insurance against an attack involving even a degraded Russian or Chinese nuclear arsenal. But this review is sure to fuel the suspicions of America’s rivals — or at least give them a pretext to expand their stockpiles and develop additional countermeasures. Trump encouraged this sort of response by saying that America’s goal is to “detect and destroy any missile launched against the United States — anywhere, anytime, anyplace.”

Not everything that drives up tensions with China and Russia is bad, of course. If expanded missile defenses provided meaningful protection against Chinese and Russian threats, or caused rivals to expend their resources in inefficient ways, the investment could be worth it. The problem is that neither of these conditions currently hold. Missile defense technology is still inadequate for dealing with near-peer competitors (although Russia and China probably believe that U.S. defenses are better than they actually are); it remains far easier and cheaper to defeat missile defenses than to build them.

It is possible that technological breakthroughs could change the situation: Directed energy weapons could prove cheaper and more effective than existing interceptors, for instance. Yet these improvements are many years in the future, if they can be realized at all. In this sense, the Missile Defense Review should be seen as an aspirational document, rather than a description of a comprehensive defense that can be achieved anytime soon.

Given that the threat is intensifying and geopolitical tensions are rising, it is entirely proper to consider whether there might eventually be more cost-effective ways of achieving a better defense. But the basic challenge of missile defense has always been that it entails paying significant costs for uncertain benefits. For all the programs and innovations the Missile Defense Review advocates, it cannot escape this fundamental dilemma.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Hal Brands is a Bloomberg Opinion columnist, the Henry Kissinger Distinguished Professor at Johns Hopkins University’s School of Advanced International Studies, and senior fellow at the Center for Strategic and Budgetary Assessments. Most recently, he is the co-author of "The Lessons of Tragedy: Statecraft and World Order."

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