ABSTRACT
Up to the present, the dominance of offense over defense has been based on technical considerations. Great strides have been made in the ability to produce, focus, and aim laser and particle beams of increasingly high power. Major technical advances have led to great improvements in the offense. The crucial question that must be addressed is whether technology now offers a new promise of changing the conditions of offense dominance. The concept of a "defense-in-depth" has evolved since no single technology alone is adequate to provide an impenetrable defensive shield, or anti-ballistic Maginot Line. The concept of a defense-in-depth envisages one or two layers operating during the mid-course phase, which for ICBMs lasts twenty to twenty-five minutes following the completion of the booster burn and prior to reentry of the warheads into the atmosphere.
