ee 7" a ae Le INTRODUCTION This study attempts to evaluate the effectiveness of alternative civil defense measures that can be taken between thefirst: warning of attack and the attack itself in reducing deaths in urban targets from immediate effects. It does not attempt to investigate the problems of social control, feeding, housing, and medical care in the months following attack that might result in additional casualties. Long-range programs designed to reduce urban vulnerability, such as blast-resistant-building design and dispersion, are treated separately in Annex B of this appendix. ness. The importance of the present study may be summarized asfollows: (a) Passive and active defenses interact to reduce or enhance one another’s effectiveFor example, a civil defense policy of mass radial preattack evacuation of urban targets might reduce active defense effectiveness by precluding the use of nuclear warheads in surface-to-air missiles against bombers attacking at low altitudes. Conversely, a civil defense policy of deep shelter for occupants of urban targets would provide the ground commander with great flexibility to meet the attack with a weapon of any likely yield at any altitude. (b) In some cases passive measures can be wholly or partly substituted for active measures. Critical facilities might be duplicated at a second location, equipment or the end product stockpiled, or the installation placed underground, and thereby serve as an alterna- tive to point defenses for thefacility. (c) Passive measures change the nature of the target to be defended. Dispersal pro- _ er et =a gramsfor industry, for example, alter the value of the target relative to its initial value and to the value of other targets in the system, and hencealter the numberof batteries required to defend it. As a second example, populations in deep shelter can tolerate high radiation levels, and thus present different targets to be defended than an exposed population — populations in shelter may reduce the need for killing at great distances the bomb thatif not killed would result in radiation conditions that could be lethal to an unsheltered population. (d) Active defenses are probabilistic in their effectiveness (App G), and the problem of enemy electronic countermeasure capabilities is a grave one (App D). Passive defenses can offer a chance for survival should the active defenses not be completed at the time of the attack or not perform as envisioned. (e) The kind of civil defense plans that exist, and their effectiveness, crucially affect the Army’s preattack and postattack role. Lack of passive defense plans, or passive plans that lead to chaos or personnel losses of unmanageable proportions, may require the use of so many Armyresources that it will be impossible for the Army to carry out its primary mission. (f) Recent events have highlighted the role the military forces may have to play in civil defense. The declaration of martial law by the President in Operation Alert, 1955, has been subject to a wide variety of interpretations. At one extreme this move was ORO-R-17 (App B) 7 CONFIDENTIAL