The Anti-Ballistic Missile Debate

One of the great problems in arms control is that advances in technology, and their application to military programs, tend to invalidate or render meaningless even the soundest arms-control proposals. Twice in the last decade this has occurred, once when the diffusion of nuclear technology and the production of large numbers of nuclear weapons rendered futile any hope of complete nuclear disarmament, and again when the advent of intercontinental missiles made necessary a rethinking of all the proposals for limiting or abolishing strategic strike forces. It may well be that we are about to witness a similar overtaking of current arms-control proposals because of the possibility of deploying highly effective ballistic missile defenses.

Although work on anti-ballistic missiles has been under way for some years, the prospects for their being really effective have in the past seemed relatively small. As Secretary of Defense McNamara and others have indicated, this was due largely to the development of sophisticated penetration aids (chaff, decoys, nose cones whose wakes were not easily identifiable by radar, etc.), so that incoming warheads could not be readily distinguished at the optimum altitudes for engagement by anti- ballistic missiles. Under these circumstances, the cost/effectiveness of such missiles was relatively low, in that an enemy could penetrate missile defenses with comparative ease. Alternatively, he could simply bypass local defenses by striking at undefended targets or by exploding large-yield weapons up-wind from defended ones. To cope with this latter threat, and with the possibility of fallout-or even blast damage-from defending missiles detonated at low altitudes, ballistic missile defenses had to be complemented by shelters capable of protecting against fallout and resistant to blast pressure. All in all, it is understandable that the United States did not deploy anti-ballistic missiles during the early sixties.