According to a new report from the Union of Concerned Scientists and analysts at Massachusetts Institute of Technology's Technology Security Studies Program, the proposed National Defense System will not work. After analyses of potential countermeasures that could be taken by aggressive states, they conclude "that the planned NMD system would not be effective against the limited long-range missile threats it is intended to defend against -- whether from Russia, China, or emerging missile states. We also conclude that deploying the planned NMD system would result in Russian and Chinese reactions that would decrease US security.
Thus proponents of the NMD inadvertently are contributing to destabilization of the nuclear balance of arms that has averted nuclear war for the last 5 decades.
The UCS's analysis shows the problem goes far deeper than the fact that early tests are failing consistently…it isn't just that this generation of technology is incapable of providing reliable defense. The real Achilles heel of an ABM system is that it is far cheaper and easier for an aggressor to add new missiles or countermeasures to its offensive tactics and evade the defense than for a defender, dependent upon ABMs, to increase the effectiveness of the defense system.
With this dynamic, when one country builds an ABM system, its opponents are motivated to add to their weaponry… build more missiles, develop more sophisticated countermeasures. The aggressor can do this more quickly, cheaply and effectively than the defender. The result is an arms race that the defender can never win.
The US is under a legal obligation, the Anti-ballistic Missile Defense Treaty, to not build an ABM system. The Administration is currently attempting to negotiate with Russia a re-opening of the treaty to allow construction of a limited ABM system. To do so will have a profoundly destabilizing impact on international arms control efforts.