09/23/2009 - 10:22

Technical flaws in the Obama missile defense plan

David WrightLisbeth Gronlund

Lisbeth Gronlund

A physicist, Gronlund codirects the Union of Concerned Scientists' (UCS) Global Security...

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David Wright

A physicist, Wright codirects the Union of Concerned Scientists' (UCS) Global Security Program. His expertise is in...

More

Last Thursday, the Obama administration announced its long-awaited decision on a European missile defense system against potential Iranian ballistic missiles. In short, it will shelve the Bush administration's plan for a defense against intercontinental-range missiles, and instead, it will field a system designed to intercept shorter-range missiles, on which Iran is making quicker progress.

The White House made the right decision in cancelling the Bush plan, which had a raft of technical and political problems, and it deserves credit for changing course. But the new plan also has significant problems, and the announcement demonstrates that U.S. missile defense policy continues to be based on domestic politics rather than technical reality.

There certainly was no technical justification for deploying the Bush administration's planned system, which would have placed ground-based interceptors in Poland and a large radar in the Czech Republic. The planned interceptors were to be modified two-stage versions of the three-stage interceptors currently fielded in Alaska and California as part of the ground-based missile defense intended to protect the United States against long-range missile attacks. But the two-stage interceptors haven't had any flight tests, and the three-stage versions haven't undergone rigorous, realistic flight-testing. Thus far, the tests have been highly scripted and haven't included realistic countermeasures or other complications that the system would expect to face in a real-world attack. Both versions of the interceptors are designed to intercept missiles in the vacuum of space, where decoys and other countermeasures would be highly effective.

In other words, as a group of leading scientists wrote in a July letter to President Barack Obama, the system slated for Eastern Europe "has not been proven and does not merit deployment. It would offer little or no defensive capability, even in principle."

So instead, the Obama administration is planning to deploy in Europe the existing ship-based Aegis defense system, which is designed to intercept short- and intermediate-range missiles with a range of up to 2,000 kilometers. According to the plan, the United States will develop and field interceptors against longer-range missiles in the future.

A key technical problem with this approach is that the Aegis interceptors (current and planned) also are designed to intercept missiles above the atmosphere and therefore, would be vulnerable to decoys and other countermeasures, just like the current ground-based interceptors.

At the press conference announcing the missile defense decision Gen. James Cartwright stated, "One thing I'm relatively sure of is that the threat will change. We have a thinking adversary, and we have to acknowledge that." But the Pentagon also needs to acknowledge that in the face of missile defense any "thinking adversary" will deploy decoys on any missiles it builds.

President Obama has repeatedly stated that missile defense systems must be "proven" before they are deployed. And as he stated last week, he considers the Aegis interceptors proven. However, his criteria for a "proven system" is disappointingly weak: While the Aegis interceptor has done well in recent tests, it hasn't been tested against countermeasures or under real-world conditions. Such tests are needed before the system can be considered to be effective.

Obama's switch on missile defense in Europe did accomplish something important in the near-term, since it removed a major irritant in U.S.-Russian relations that stood in the way of greater security cooperation. As such, it may be easier to get Russian assistance in dealing with potential Iranian threats, as well as on bilateral disarmament agreements. On the other hand, the Aegis plan has its own security downside and will raise important strategic questions over the next decade and beyond.

Starting in 2011, the U.S. plans to deploy Aegis ships in European waters and develop land-based versions of the interceptor. Rather than deploy a large, fixed-site radar such as the one proposed for the Czech Republic under the Bush plan, the new system will use a network of sensors, including the radars on the Aegis ships cruisers and mobile X-band radars.

Over the next 10 to 15 years, the military wants to equip Aegis ships with a much larger, faster interceptor that the United States is developing cooperatively with Japan. Estimates suggest that the interceptor's speed will be high enough--in principle--to allow it to intercept missiles with intercontinental range. As Defense Secretary Robert Gates and General Cartwright noted repeatedly during their press conference announcing the missile defense decision, the long-range goal is to deploy a global network of mobile interceptors and sensors. Cartwright explicitly stated that the United States intends to build "a sufficient number of ships to allow us to have a global deployment of this capability on a constant basis, with a surge capacity to any one theater at a time."

The Bush administration argued that its ground-based missile defense system, as well as its planned European system, only was intended to defend against small attacks from emerging missile states, and that Russia and China shouldn't be concerned since only a small number of interceptors would be deployed. However, since hundreds of Aegis interceptors now are planned, with an improved next generation of interceptors to follow, it's likely to provoke both Russian and Chinese concerns.

Defenses against nuclear-armed, long-range ballistic missiles will never be effective enough, and militaries will never trust them enough, to fundamentally affect nuclear deterrence. However, Russian and Chinese policy makers--like many of their U.S. counterparts--may overestimate the effectiveness of such defenses or choose to ignore the technical realities. Thus, if the number and capability of Aegis interceptors increase significantly in the future, Russian hawks might use the U.S. system to argue against meaningful reductions in Russia's nuclear arsenal and other steps to reduce the nuclear threat. China's hawks will be able to make an even stronger case since their country has a much smaller arsenal. So only time will tell if the Obama missile defense plan really has made an improvement in U.S. and European security.