A report by the Pentagon's own Defense Science Board (DSB) has poured cold water on U.S. missile-defense plans. It basically backs up what independent scientists and engineers have been saying for decades: a dedicated adversary easily could defeat the planned system by using simple decoy warheads and other countermeasures. So while missile defense will create incentives for U.S. adversaries and competitors to up their ballistic-missile stockpiles, it won't provide any combat capability to counteract these enlarged arsenals.

The simplest countermeasures to the planned missile defense are cheap inflatable balloons. Because the missile-defense interceptors try to strike ICBM warheads in the vacuum of space, any such balloons and the warhead would travel together, making it impossible to tell the decoys from the real thing. An enemy bent on delivering a nuclear payload to the United States could inflate many such balloons nearby the warhead and overwhelm the defense system by swamping it with fake signals.

The DSB report says that “the importance of achieving reliable . . . discrimination [between the warhead and decoys] cannot be overemphasized.” It underlined that missile defense is “predicated on the ability to discriminate” real warheads from other targets, “such as rocket bodies, miscellaneous hardware, and intentional countermeasures.” One way around this challenge is to attempt to intercept the missile before it releases the warhead and decoys. But intercepting missiles in their boost phase, while the rocket booster is still firing, is “currently not feasible,” according to the DSB.

There is a short interval between the time the missile stops burning and when the payload is released, assumed to be about one hundred seconds by the DSB. But, again, intercepting the missile in this window “requires Herculean effort and is not realistically achievable, even under the most optimistic set of deployment, sensor capability, and missile technology assumptions.” The main problem the DSB found is that missile-defense interceptors would not be able to reach the target quickly enough: “in most cases 100 seconds is too late” to prevent the release of decoys. And if “the defense should find itself in a situation where it is shooting at missile junk or decoys, the impact on the regional interceptor inventory would be dramatic and devastating.” In short, the interceptor inventory would be exhausted in chasing decoy warheads.

The latest tests of both the ground-based and sea-based missile-defense systems have failed—and these are rigged tests, where the intercept team knows the timing and trajectory of the incoming missile, and the missile has no decoys. There are no such luxuries in the real world, where adversaries launch surprise attacks and use countermeasures and decoys. And on the very few occasions that the Missile Defense Agency (MDA) has tested countermeasures, even these carefully rigged tests have never succeeded. The sea-based missile-defense system also has never been tested in really rough sea conditions and is known to be unreliable.

How did such an untested and unworkable technology make it so far in the DoD procurement process? Another recent government report, this one from the GAO, explains that instead of flying before buying, the MDA has been doing the exact opposite. Its cart-before-the-horse methodology has resulted in “unexpected cost increases, schedule delays, test problems, and performance shortfalls.”

All told, the missile-defense program has cost more than the entire Apollo program without providing any credible combat capability against enemy ballistic missiles hosting simple countermeasures.

The Reaction

If missile defense is so dysfunctional and so simple to outfox, why do U.S. adversaries appear to be so concerned? The answer is simple: their military planners are hypercautious—as are the ones in the Pentagon—and must assume a worst-case scenario in which the system is highly effective.

Missile defense will therefore strengthen the hands of overcautious, misinformed, opportunistic or hawkish elements within the Iranian and North Korean—as well as Russian and Chinese—political and military establishments. Both unknowable future circumstances and pressures from hawkish internal constituencies will pressure all these regimes to increase deployed nuclear stockpiles and military expenditures.

Since the interplay between strategic defense and strategic offense is explicitly recognized in the New Strategic Arms Reduction Treaty (New START) between the United States and Russia, it is highly improbable that Russia will ever accept NATO missile defense, even if it's dysfunctional. Any system that raises uncertainties about the strict balance of arms agreed upon in New START is a natural concern to both parties.

The United States and NATO have repeatedly stated that the system is not directed at Russia and poses no threat to its nuclear-deterrent forces. And though NATO has invited the Russians to join the program, there has been no consensus on the degree or the form of that participation. Moscow prefers to develop a joint European missile-defense network with NATO to ensure that the elements of the system (in a number of European countries) will not threaten Russia’s national security. NATO, in contrast, proposes the creation of two entirely separate systems that would exchange information. To date, missile-defense talks between Russia and NATO are deadlocked over this contentious issue.

Chinese concerns about U.S. missile-defense systems are also a source of great uncertainty, reducing Chinese support for promoting negotiations on the Fissile Material Cutoff Treaty (FMCT)—China's leaders may wish to maintain the option of future military plutonium production. The bipartisan Strategic Posture Commission points out that “China may already be increasing the size of its ICBM force in response to its assessment of the U.S. missile defense program.”

Strategic Uselessness

But if Tehran obtains nuclear weapons, surrounding it with missile defenses, no matter how effective, will never eliminate the threat that a single missile could penetrate the defense system—especially given how easy it is to outfox the system by using decoys. Thus, the United States can never neutralize the deterrent value of any possible future Iranian nuclear ballistic missiles with any incarnation of missile defense. A nuclear-armed Iran would have to be treated identically by Washington whether or not missile defenses were in play.

The strategic uselessness of missile defenses aimed at devaluing nuclear-tipped missiles is a conceptual problem, not merely a technical one. The reason is simple: there is always a reasonable probability that one or more nuclear missiles will penetrate even the best missile-defense system. Since even a single nuclear-missile hit would cause unacceptable damage to the United States, a missile-defense system shouldn't change U.S. strategic calculations with respect to its enemies. Washington would treat North Korea, Iran and other adversaries the same before and after setting up a missile-defense system.

It's often asserted that missile defenses dissuade adversaries from researching and producing ballistic missiles. But the countries developing ballistic-missile technology do so for numerous reasons, not just to launch nuclear attacks against the United States. Many countries desire conventional ballistic-missile technology for prestige or regional security. Whether or not a U.S. missile-defense system is operational, such nations will still try to acquire ballistic-missile technology. In fact, the countries of most interest to the United States—Iran and North Korea—currently have reasonably well-developed ballistic-missile programs. They have not been dissuaded by the missile-defense “shield.”

And even if some future incarnation of missile defense could be made to work effectively, it would only encourage a change in the delivery method of the nuclear weapons used by our adversaries. It would not devalue the nuclear weapons themselves. A "functional" missile defense to counter North Korea’s ICBMs, for example, may encourage the nation to develop a ship-launched nuclear cruise missile instead or to deliver nuclear weapons directly by boat. Since a cruise missile or boat-borne nuclear device is more difficult to detect and attribute to a given country, our adversaries may be less inhibited in using such delivery methods as compared to an easily detected ICBM with a clear point of origin.

Missile defense will not counteract any possible future Iranian ICBMs with simple countermeasures—but it will erode relations with Russia and China right now. Because it encourages adversaries to assume the worst and creates incentives for them to increase their nuclear stockpiles, it will also lead to more nuclear weapons and a more dangerous world. There is simply no upside to a dysfunctional missile “defense” and plenty of downsides in addition to its gargantuan cost.

Yousaf Butt is a nuclear physicist and serves as a scientific consultant to the Federation of American Scientists, a DC think tank.