Could the Strategic Defense Initiative really work? Wouldn't it destabilize

relations with the Soviet Union? Dr. Keyworth's technical credentials are unassailable, and he proves able to explain difficult concepts so that non-physicists can grasp them: "The Soviets' definition or perception of the word 'deterrent' requires that they maintain a pre-emptive strike, a first-strike capability, whereas for us it is purely the maintenance of a retaliation. If we can reduce those perceptions to a common ground--and I would contend that even a moderately effective ballistic missile defense system does, because it removes any military validity, any validity at all, to a Soviet pre-emptive first strike--if it

does that, then we are both left with the threat of retaliation, which is where we started from decades ago, which is far more stable than the situation today."