Limited Nuclear War

SCIENTIFIC Established 1 845 AME RI CAN November 1976 Volume 23 5 Number 5

Limited Nuclear War

The U.S. may be committing itself to preparing for a war limited to attacks on military bases, with relatively few civilian casualties.

Would the casualties really be few, and could the war stay limited?

by Sidney D. Drell and Frank von Hippel

or more than a decade U.S. strate that a flexiblecapability would make inger supported his advocacy of such a F gic policy has been dominated by the possibility of a U.S. nuclear attack counterforce capability by suggesting the recognition and acceptance of more credible and would thus increase that a counterforce strike against the a few simple facts: We and the Russians the leverage provided by U.S. nuclear U.S. might result in "hundreds of thou are each other's nuclear hostages; in the forces in international confrontations. sands" of civilian casualties "as opposed event of nuclear war neither this country Since 1974 Schlesinger and other de to tens and hundreds of millions," which nor the U.S.S.R. would be able to de fense spokesmen have emphasized what could result from an all-out nuclear ex fend itself against virtual annihilation; they now seem to regard as two neces change. Several senators were skeptical even if one side were to initiate the war sary new ingredients of a flexible-re that a militarily significant strike could with a massive preemptive attack, the sponse strategy. One is the development cause so few casualties; Senator Clifford other would retain an "assured destruc of intercontinental ballistic missiles P. Case of New Jersey in particular tion" capability, the ability to devas (ICBM's) capable of destroying "hard asked that the basis for the casualty cal tate the attacker. In one form or another ened" Russian military targets, such as culations be further explained. In Sep this recognition has underlain most of missiles emplaced in blast-resistant un tember, Schlesinger returned with De the past quarter century of mutual de derground silos. The other is a major partment of Defense computer calcula terrence. expansion of the civil defense program, tions on the consequences of limited nu It has also been recognized, however, which has been largely inactive since the clear war. The figuresindicated that if that nuclear weapons might be launched early 1960's. The purpose of the civil extensive civil defense protection were with restraint on both sides, with less defense program would be to improve available and taken advantage of, a Rus than devastating results. President Nix the credibility of the U.S. limited-nucle sian attack on all 1.054 Minuteman and on emphasized in 1970 the importance ar-war posture by protecting the civilian Titan ICBM's, with one one-megaton of having options other than "massive population from the effects of limited warhead targeted on each silo, would retaliation" for replying to a small (and Russian nuclear attacks. The new em cause about 800,000 civilian deaths. possibly accidental) attack. That formu phases give more weight to achieving a Schlesinger concluded from this that lation of flexible response was nothing capability for fightingand "winning" a "the likelihood of limited nuclear at new. U.S. leaders have for many years limited nuclear war. tacks cannot be challenged on the as had the option of launching a limited This proposed shift in strategy and the sumption that massive civilian fatalities nuclear attack rather than an all-out weapons-development and civil defense and injuries would result." one. The requirements of flexible re measures being sought to support it Some senators were still skeptical. sponse were expanded, however, by for have come under attack on two broad and the Congressional Office of Tech mer Secretary of Defense James R. grounds. First, detailed calculations nology Assessment (OTA) was asked to Schlesinger in Congressional testimony based on the properties of nuclear weap review the Defense Department calcula on March 4, 1974. According to his for ons of the coming decade suggest that tions. An expert panel including one of mulation, the U.S. should include in its the casualties from any militarily signifi the present authors (Drell) reported flexible-response repertory the possibili cant nuclear counterforce strike would back in February, 1975, that "the casu ty of replying to a limited nuclear attack be so devastatingly high that this con alties calculated were substantially too with selected strikes, notably "counter cept of limited nuclear war loses mean low for the attacks in question as a result force" strikes targeted against enemy ing. Second, a counterforce strategy of a lack of attention to intermediate military installations. Schlesinger ar founded on the ability to destroy ene and long-term effects" of the nuclear ex gued that such strikes would be qualita my ICBM's increases the chances of nu plosions. Pointing out that the Russian tively different from intentional attacks clear war. strike postulated by the Defense Depart on population centers, reducing the ment was "evidently not designed to probability that a limited nuclear war n his testimony before a subcommit maximize destruction of U.S. ICBM's," would escalate into a massive exchange I tee of the Senate Committee on For the panel insisted that a real Russian ef resulting in large civilian casualties, and eign Relations in March, 1974, Schles- fort to cause maximum damage to U.S.

© 1976 SCIENTIFIC AMERICAN, INC MINUTEMAN III missile combat-crew commande r's console con ground) is that of the Command Data Buffer system, which makes trols the launching of a flight of 10 missiles. The keyboard (fore- possible the resetting of targets in on-board computers in 36 minutes.

- II

MINUTEMAN II console shown here is that of the deputy combat centers. The U.S. has 450 Minuteman II's and 550 Minuteman Ill's, crew commander. The consoles arein underground launch-control the latter with multiple independently targetable reentry vehicles.

© 1976 SCIENTIFIC AMERICAN, INC strategic forces with weapons currently ties alone would be between 50,000 and lower. For such targets it is radioactive deployed or under development would 100,000 per one-megaton warhead ex fallout that would account for most of in fact "inflict massive damage on U.S. ploded high enough so that local radio the civilian casualties, and the fallout society." The panel raised specific ques active fallout would not be a hazard. from a Russian attack on a Minuteman tions about some of the assumptions un For military targets in places with a base could be lethal many hundreds of derlying the Defense Department's cal low population density, casualties from miles downwind. Considering the weap culations, and it also asked for estimates these immediate effects would be much ons that are deployed today or are likely of the probable degree of damage to U.S. military targets for postulated at tacks. This is a critical point, since it would be specious and misleading to calculate a low casualty figure for some imagined trivial-and therefore unlike ly-counterforce attack. In response to the panel's critique De fense Department analysts tested the sensitivity of their calculations to the as sumptions challenged by the panel and estimated the effectiveness of various possible Russian strikes. In what follows we shall consider these issues and some of the underlying technical factors. We shall draw in part on the Defense De partment's results, which were reported in July, 1975, and also on an indepen dent analysis, produced by Henry C. Kelly of the staff of the Office of Tech nology Assessment in collaboration with Richard L. Garwin and one of us (von Hippel), presented to the Commit tee on Foreign Relations that Septem ber. What emerges is this: Strikes caus ing relatively few casualties would be militarily insignificant; strikes inflicting appreciable damage on U.S. strategic forces would cause very large civilian casualties; even the most comprehen sive counterforce attack that was postu lated would leave the U.S. with such massive retaliatory capability as to make the counterforce strategy appear to be ineffective from the Russian point 10 MILES of view.

CAUSE EFFECT We begin by examining the tech niques for calculating the civilian THERMAL BURNS AND FIRES, POSSIBLE FIRE STORM casualties resulting from a nuclear at RADIATION tack. Casualty levels depend sensitively CASUALTIES FROM BUILDING COLLAPSE BLAST on many factors, such as the nature of AND FLYING GLASS the attack, weather conditions and civil � NUCLEAR defense protection. The basic physics of RADIATION DEATHS warhead effects, however, is fairly well � RADIATION established and widely known; it is set forth most comprehensively in The F;! IMMEDIATE EFFECTS of a nuclear explosion are due to the initial nuclear radiation, the feets of Nuclear Weapons, a publication air blast and the thermal radiation. The approximate radii at which the various effects would of the Department of Defense and the be significant are given here for a one-megaton nuclear warhead exploded near the surface. Atomic Energy Commission, edited by Samuel Glasstone, that was published originally in 1957 and in revised form DOSE (IN REMS) in 1962. IF DELIVERED IF DELIVERED EFFECT For a low-altitude nuclear explosion OVER ONE WEEK OVER ONE MONTH releasing the energy equivalent of a mil THRESHOLD FOR 150 200 lion tons (one megaton) of TNT the im RADIATION ILLNESS mediate effects of blast, heat and nu clear radiation would extend over an 250 350 5 PERCENT MAY DIE area around ground zero with a radius of about 10 miles. At military targets 450 600 50 PERCENT MAY DIE near populated places, such as naval shipyards, missile-submarine bases and some command centers, the Defense BIOLOGICAL EFFECTS of nuclear radiation vary with the rate at which a dose isdelivered. Department calculated that blast fatali- The dose unit, the rem, takesinto account the relative effectiveness of the type of radiation.

© 1976 SCIENTIFIC AMERICAN, INC DEUTERIUM TRITIUM to become available in the next decade. 0 o such an attack might be delivered by one megaton or two megatons of nuclear ex plosive fuzed to detonate near the sur face at each of the 15 0 or 200 hardened ICBM silos at the base. Radioactive fallout originates with the thousands of tons of soil. rock and other material that would be melted or vaporized by the heat of each explosion and mixed with its radioactive by-prod HELIUM ucts. This debris would be carried to a height of some eight miles with the ris 1 "b ing fireball. In the stratosphere the fire ball would cool and the larger particles � / would descend to the ground within a day or so. over an area extending some hundreds of miles downwind. as "local" URAN'UM '" fallout. The smaller particles would o -drift great distances and eventually de scend as global fallout. / � The hazards of local fallout were dramatized by the events that followed the first U.S. test of a fission-fusion-fis sion bomb (with a yield of 15 megatons) at Bikini Atoll on March 1. 19 54 [see illustration on opposite page]. Fishermen 80 miles downwind received radiation doses that ultimately killed one of them. At the south end of Rongelap Atoll. 10 0 miles downwind. people suffered severe short-term and long-term radiation ef fects. If they had been living at the north end of the atoll. the higher radiation lev els there would almost surely have killed them. If people in the local-fallout zone did (1 SECOND) (25 MINUTES) not (as the residents of Rongelap did) ingest contaminated food and water. the principal hazard would be external radi ation from radioactive particles. (Most MOLYBDENUM 104 TELLURIUM 131 of the particles in local fallout would be too large for inhalation into the lungs.) If people did not stay outdoors and come into direct contact with fallout. (1.6 MINUTES) thereby sustaining burns caused by beta particles (the short-range electrons emitted by radioactive nuclei). the ma jor hazard would be the more penetrat TECHNETIUM 104 IODINE 131· ing gamma radiation.

n order to determine the distribution I and consequences of local fallout one needs to know the fission yield and (18 MINUTES) (8 DAYS) height of burst of each warhead. the bio logical effects of a given absorbed radia tion dose. the dependence of the fallout pattern on weather conditions. the de XENON 131 RUTHENIUM 104 gree to which the population is sheltered and the geographic distribution and to tal megatonnage of the attack. Predic tions of fatalities and injuries are sensi FISSION PRODUCTS, the source of fallout radiation, are produced in the chain of events fol tive to the assumptions one makes about lowing a nuclear explosion, in this case a typical fission-fusion-fission explosion. Heated by an each of these factors. which we shall initial fission explosion, the hydrogen isotopesdeuterium and tritium fuse to form helium, re consider in turn. leasing an energetic neutron (colored arrow). The neutron enters the nucleus of a uranium- The radioactivity in the fallout would 238 atom, making it unstable; it fissions,releasing four neutrons and two radioactive daughter come mostly from fission. A "thermo nuclei, or fission products. The fission products emit beta rays, or electrons (broken ar nuclear" weapon is typically a fission rows),and gamma rays (wavy arrows), thus decaying to form new products. Each decay chain ultimately terminatesin a stable isotope. For each transition there is a characteristic half-life, fusion-fission device. A "small" fission which tends to become longer as the stable stage is approached. Other decay chains, not illus explosive (one of the chain-reacting iso trated here, produce the important long-lived radioisotopes strontium 90 and cesium 137. topes uranium 23 5 or plutonium 239)

BIKAR I::)61 GROUND ZERO

UTIRIK \]18�14 104 rztI--_-=-c:-=-:::�=- TAKA AILINGINAE RONGELAP I I I I I I I I I 00 00 100 1W 1� 100 100 � � 240 260 280 300 320 340 DISTANCE FROM GROUND ZERO (MILES)

HAZARDS OF LOCAL FALLOUT downwind from a tbermo measurements (black numbers) give tbe total dose, in rems, tbat nuclear explosion were dramatized by tbe U.S. test of a IS-megaton bad accumulated 96 bours after tbe explosion. Contour lines calcu fission-fusion-fission bomb on Bikini Atoll on Marcb 1, 19S4. Tbe lated on tbe basis of tbose measurements outline tbe fallout pattern.

triggers a fusion explosion involving, of hair ... also starts after about two amount of fallout deposited downwind, for example, the hydrogen isotopes deu weeks. . .. Ulceration about the lips would be affected by the choice of tar terium and tritium. The high-energy may ...spread from the mouth through get. In the counterforce attacks envi neutrons emitted by the fusion reactions the entire gastrointestinal tract." Even sioned by the Defense Department most then fission the nuclei of a large amount tually "the decrease in the white cells of of the mega tonnage would be directed of the non-chain-reacting isotope urani the blood and injury to other immune against underground Minuteman silos. um 238, releasing more fission energy mechanisms of the body ... allow an The Department reported that the Min [see illustration on opposite page]. In the overwhelming infection to develop." uteman-killing effectivenessof surface Defense Department calculations 50 One has only to multiply that descrip bursts and of airbursts at the "optimum percent of the energy release was as tion by the millions to get a partial pic height of burst" would be about equal. sumed to be due to fission, and that is a ture of the possible consequences of (The optimum height of burst is the representative fraction. "limited" nuclear attacks on the U.S. height that, for a given yield, provides a The biological consequences of gam and the U.S.S.R. blast pressure exceeding a certain value ma radiation depend on the total dose over the largest area; for a one-megaton received and the time period over which f the fresh fission products from one yield and an overpressure of 1,000 it is delivered. The median lethal radia I megaton of fissionwere spread uni pounds per square inch it would be tion dose was taken by Defense Depart formly over a perfectly flat area of 1,000 about 1,000 feet.) The attacker would ment analysts to be 450 rems for doses square miles, the gamma-ray dose rate thus be faced with a trade-off. On the received within a few days. (The rem, one meter above the ground would be one hand a surface burst does not have standing for "roentgen equivalent man, " about 250 rems per hour after 10 hours. to be as precisely placed as an airburst is a unit of the biological effect of radia For human beings the median lethal (an important consideration, since at tion.) For doses delivered over a longer dose at such a high dose rate is about tacks on hardened targets put a high pri time the lethal dose was taken to be 450 rems. The gamma-ray dose rate ority on accuracy). On the other hand, somewhat higher because, given time, a would decrease about sixteenfold for Defense Department calculations show biological system can repair a consider every tenfold increase in time for the that, other things being equal, for an at able amount of radiation damage. The first six months after the explosion and tack on the U.S. ICBM's fallout fatali effective dose suffered by the exposed more rapidly thereafter. In our example ties could be four times higher for sur population when the rate of repair just the radiation intensity would be down to face bursts than for airbursts. balances the rate of damage being done about 15 rems per hour after four days The fireball from a one-megaton nu by the decaying ambient field of radia and about one rem per hour after 40 clear explosion and the fission products tion would be the "maximum biological days. For a person remaining in the ra it contains rise rapidly until the top of dose" and would determine the lethality diation zone, however, the cumulative the cooling fireball cloud enters the of the 'exposure. dose would continue to rise significantly stratosphere, about six miles above sea Death from radiation sickness would for quite a long time. Consider the local level at middle latitudes. At a height of be neither quick nor painless. As de fallout beginning about 10 hours after about eight miles the cloud stabilizes, scribed in the Glasstone book, "the ini an explosion, which is a typical time for with its fission products spread over an tial symptoms are ...nausea, vomiting, the fallout to reach ground level. A full area about four miles in diameter. An diarrhea, loss of appetite and malaise." 40 percent of the dose accumulating af average settling time for the local fall Beginning two or three weeks after the ter that time would remain to be deliv out from a one-megaton explosion exposure "there is a tendency to bleed ered after four days, and 25 percent of it might be about eight hours. The settling into various organs, and small hemor would still remain to be delivered after time and the average speed of the winds rhages under the skin ...are observed." 40 days. between the top of the fireball cloud and Spontaneous bleeding from the mouth The height of burst of the warheads, the ground determine how far the parti and intestinal tract is common. "Loss which has an important influence on the cles drift downwind. For a typical aver-

© 1976 SCIENTIFIC AMERICAN, INC 1 age wind velocity of 20 miles per hour hour, the pattern of fallout 10 0 miles 100�------U------'-� M I SS O R I the average drifting distance would be downwind from ground zero would be iii 160 miles. (The settling time also deter about 25 miles wide. w -' mines the extent to which short-lived ra Clearly the number of casualties de � 50 KANSASCTy ------1 dioactive isotopes decay harmlessly be pends to a considerable degree on what o z fore reaching the surface.) The width of weather conditions are assumed. In the the fallout pattern is determined primar Defense Department calculations the 3: ----_, � OH-----�--�------/7------H ily by the differences in the speed and total casualties from one postulated at � -� --=::-::..-:.------.-- direction of the winds to which particles tack were three times higher with typical u w are subjected at various heights in the March winds blowing than they were U I WHITE MAN A R FO RCE BASE cloud. For a typical wind shear of one with typical June winds. Such variations z 50H------4 mile per hour per mile of height and are largely due to changes in wind direc (/)� Ci an average wind speed of 20 miles per tion and wind speed that cause the fall out pattern to cover certain densely pop � 100WL ______ulated areas or miss them. Consider the fallout pattern downwind from the Min Air 2 uteman wing at Whiteman Force ------Base in central Missouri after a Russian 100 � �M�I�SSO� U7.R�I ,-�� ------r- , attack by two one-megaton surface ill" I I bursts (with 50 percent of the yield from -' SPR NGF ELD . fission) on each of the base's 150 silos. � 50 KANSAS CITY------'...,...------�------_+--__i o With an average wind velocity of 20 z -=::.=-=..-:..------miles per hour the lethal fallout zone 3: for people indoors would stretch to the � OH-----�------_; o Illinois-Indiana border; with an aver a: u age wind velocity of 60 miles per hour w U (which is not an unusual speed high z 50�------��------_7L-----__1in the troposphere, where the fallout (/)� would be for most of the time before it Ci

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4 ------7.7��------r7. � 7 � �------O IO ------100� �M�I�S7S70U� 7R �I -.� IND AN1 A -,� ��H �� I I ______(j) SPR NGF ELD ______. - -= =- --= -=-:.....=-=-=--= =-=-- -;;-;,;;-=-;;-;;;-=-;; -,;;-..:.;;,;;;- ;;'- ;;;-':':'- =- = ------ANSAS IY-- =---� =��-:!�/ -::-=-:::-�-�----�� =- =---= =-=-= - =::::;;';�;;;; i 50 K C T =::::== �:= =t � � f ;;;:;�==:: o I I z IND ANAPOL S 3: � OH-�--�--�-U�------ o a: u 50 ::::�� t;======:::::::::: �� ;;;;;;� �� :; �� (/) � :::: �;;;;;; � � �� Ci 100�-----+------1-----��-----+------�--��r---��------t-----�------r------t------+------r------� 50 o 50 100 150 200 250 300 350 400 450 500 550 600 650 O DISTANCE D WNWIND (MILE S)

FALLOUT PATTERNS are shown for attacks by one-megaton 1,350 rems outdoors, or 450 rems (50 percent fatalities) inside an av warheads (with 50 percent of their explosive yield from fission) ex erage residence (solid line); 450 rems outdoors (broken line), and ploded at the surface on ICBM's at Whiteman Air Force Base in 150 rems outdoors (dotted line), the approximate threshold for fatali Missouri, The contours correspond to maximum biological doses of ties. The four patterns are for a single warhead (1), for one warhead

© 1976 SCIENTIFIC AMERICAN, INC settled to the ground) it would stretch all residence may have a protection factor society. Identified shelter spaces and the way to the Virginia border [see illus of 20 to 40 if it is completely below evacuation plans by themselves would tration on these two pages]. The area with ground level and therefore receives not constitute an effective civil defense in the lethal-dose contour would be very gamma radiation almost entirely from program; a total system would have to large: about 2 percent of the land area of fallout that lands on the roof of the be organized and woven into civilian life the continental U.S. building. through training programs, rehearsals There are six Minuteman bases from In the Defense Department calcula and volunteer activities. which comparably massive fields of le tions the postulated distribution of pro thal radiation would extend, and three tection factors corresponds to assuming An idea of the magnitude of a civil de IS-missile Titan bases as well. Hence that about 60 percent of the people in £\. fense program that could achieve in the event of a counterforce strike the U.S. would seek and reach the best high shelter occupancy and maintain it against U.S. missiles a substantial por shelter available in their area [see top for several weeks or longer can be tion of the U.S. would be covered by the illustration on page 35]. The 40 percent gained from the system envisioned by downwind radiation patterns from the who did not seek shelter or for whom the 1962 U.S. civil defense guide. The thousands of nuclear explosions. And a shelter was not available were assigned plans, which were never implemented, significant fraction of the population, a protection factor of 3, that of an aver contemplated that for every shelter ac including the residents of many major age residence. It was found that halv commodating 100 civilians there should Middle Western cities, would be in the ing the protection factors increased be an operating cadre of 25, of whom zones of lethal radiation [see illustration the number of deaths by more than 50 10 or 12 would need training. That is. on next page]. Presumably a map of the percent. 10 percent of the sheltered population. U.S.S.R. would show a similar pattern It is important to note that the De or 20 percent of the adult population. for a U.S. counterforce attack on that fense Department analysts assumed that would have to be trained. To recruit country. people would remain sheltered for 30 such a large cadre the Government days. At the current level of civil de would have to look beyond existing he consequences of being caught in fense preparation it is highly unlikely community safety personnel such as po Tthe fallout pattern downwind from a that the population could remain so well licemen, firemenand National Guard low-altitude or surface fission explosion sheltered for such a length of time. For a units. would depend, of course, not only on limited nuclear war to be taken seriously One task of these trained people the level of ground contamination but as a policy option-as a realistic threat would be to operate communication also on where one took refuge. Current in a confrontation with the U.S.S.R. systems over substantial distances in or ly the U.S. civil defense program re it would be necessary to make much der to deal with any local shortage of quires that for a shelter space to be iden better shelter arrangements. In other food, water or medical supplies. They tified as such it must shield against all words, the U.S. would have to embark would also have to know how to use but 1 to 2 percent of the fallout gamma on a greatly enlarged civil defense pro radiation dosimeters, because in the im radiation. The degree of protection a gram. mediate postattack period the fallout given shelter provides is characterized Indeed, the development of civil de levels could vary greatly from one place by its "protection factor, " which is the fense procedures requiring the massive to another. (Like snow, radioactive de reciprocal of the fraction of radiation evacuation and relocation of popula bris accumulates where it is driven, de that penetrates it. The current require tions during crises has recently been pending on the wind, the weather and ment is therefore a protection factor of proposed in the annual U.S. defense the topography, including buildings. 50 to toO. That degree of shielding can budget request as a necessary adjunct to There could be pockets of relative safety be provided by cover of approximately the new strategy. The preparations re in the midst of areas with lethal levels of two feet of dirt or 16 inches of concrete. quired for such mass movements and radiation.) The trained cadre would Those parts of a single-story residence for the support of the population for have to provide leadership in the long that are above ground level have a pro long periods away from home would period of extreme social duress after the tection factor of 3. The basement of the have a major impact on U.S. peacetime attack and reestablish services for a so-

�.

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700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350 1,400

DISTANCE DOWNWIND (MILES)

on each of the 10 silos in a flight (gray circle) of Minutemen (2) and wind. is assumed to blow toward the east. In the first three examples for two warheads on each of the 150 silos in Whiteman's 15 fligbts the wind speed is assumed to be constant at 20 miles per hour. In the (3 and 4). The large differencebetween the bottom two patterns is bottom example the wind speed is assumed to be 60 miles per hour the resnlt of a change in the assumed wind speed. In all fonr cases the (averaged at altitudes between the surface and the stratosphere).

© 1976 SCIENTIFIC AMERICAN, INC ciety with a large population of sick. in ment to such plans could be obtained of the nationwide disaster being consid jured and dying citizens. It should be without a deliberate and sustained in ered. however, an effectivecivil defense noted that Defense Department calcula tensification of public apprehension program would surely have to include tions of the consequences of limited nu concerning a nuclear war. One of the among its essential components full clear war are almost certainly serious lessons of the relatively ineffective civil scale rehearsals and survival-living ex underestimates. For example. the calcu defense program of 1961 and 1962 was ercises involving the population. If there lations omit any estimate of what may that the large expenditures for civil had been any such rehearsals. we would be one of the gravest consequences of defense and the inconveniences of a have heard about them. They would be all: the disruption of the intensely inter major shelter program could only be very difficult to conceal, and many peo dependent components that enable a made plausible to the American public ple who would have participated in modern society to function. The difficul by exaggerating the probability of nu them or would have had knowledge of ties imposed on a society trying to re clear war. them have now left the U.S.S.R. and cover with totally unprecedented levels Today we are again hearing allega would have called attention to them. of mortality and morbidity, with insuffi tions that the U.S.S.R. is developing and Yet no evidence of such exercises has cient medical care and with profound rehearsing civil defense plans involving been presented. The editor of the U.S. dislocations in the supply of food and the evacuation and relocation of large Government translation of the official water are simply ignored. Moreover, the populations. along with the dispersal Russian civil defense manual for 1974 calculations omit any consideration of and hardening of industry. These pro comments that "the Soviet Union has long-term consequences such as the mil grams are cited to indicate that the U.S. not conducted mass shelter living exper lions of genetic defects and cases of may be losing its deterrent and to spur a iments or even simulated ones as has cancer that would occur worldwide in renewed U.S. civil defense effort. What been done in the U.S." Plans and manu the decades after the postulated nuclear evidence is there in support of these alle als are very different from an effective attack. gations? operating system. A higher level of public awareness The Russians have written much on and concern and a willingness to partici the subject and have given their people he Defense Department's response pate in repeated civil defense exercises more intensive exposure to civil defense Tof July, 1975, presented new casu would be required if the U.S. intended than Americans have received. Appar alty figures and also estimates of the to develop a viable system for a massive ently they have also spent much more military effectiveness of the postulated evacuation and shelter. In the absence of money on plans and organizations and attacks. According to the new calcula sustained preparation chaos and panic have involved in exercises small num tions, a strike with two 550-kiloton war would surely ensue at the time of an bers of individuals with key skills. In heads, one a surface burst and the other attack. It is difficult to see how commit- view of the unprecedentedly large scale an airburst, against each of the 1.054

DAVIS-MONTHAN- -- -- \ �---) � -=--=.-

COUNTERFORCE ATTACK on allTitan (white squares) and patterns. Each inner contour delimits a 450-rem dose indoors (50 Minuteman (color squares) ICBM bases, with two one-megaton sur percent fatalities) and each outer contour a ZOO-rem dose indoors face bursts (50 percent fission yield) per silo, could produce these (50 percent hospitalized). Typical March wind speeds are assumed.

© 1976 SCIENTIFIC AMERICAN, INC U.S. ICBM silos would cause 5.6 mil lion fatalities (assuming a 25 percent re duction of the population-protection factors given above) and destroy only 42 percent of the silos. A heavier strike with two three-megaton warheads, one a surface burst and the other an airburst, directed at each silo would cause 18.3 z o million fatalities and destroy 80 percent i= of the silos. A "comprehensive" attack, ::i ::J with two one-megaton surface bursts on Cl. o each ICBM silo and strikes against the Cl. 46 Strategic Air Command (SAC) bases u. o and the two bases for ballistic-missile I Z submarines, would cause 16.3 million W U fatalities and destroy 57 percent of the a: w ICBM's, 60 percent of the bombers Cl. caught on the ground and 90 percent of the missile submarines in port [see bot tom illustration at right]. The effectiveness of all these attacks would be somewhat higher if one as sumed that the incoming missiles were more accurate and would be somewhat lower if one assumed that the attacking force was less than 100 percent reliable. PROTECTION FACTORS An additional factor in a massive attack involving many warheads arriving at "SHELlER POSTURE" assumed in Department of Defense calculations is given by bars about the same time in the same area is showing what percent of the population isin shelters that have given "protection factors" (the "fratricide" among the incoming mis inverse of the proportion of outsidegamma radiation penetrating the shelter). A protection siles. In a concentrated attack the atmo factor of 3 isroughly that provided on the ground floor of a one-story residence; the basement spheric disturbances created by the first of a one-story frame house could provide a factor of 15 to 20, that of a two-story brick house warheads to arrive must necessarily de as much as 50. A trench covered by two feet of earth provides a protection factor of about 100. stroy, disable or deflect many of the warheads that arrive later. Only the al most perfect synchronization of the ar 18.3 rival of warheads that are aimed at the same silo or nearby silos can avoid this effect. In any case it is clear that even with a massive attack resulting in enormous Ul devastation, including the direct death z of 20 million Americans, the U.S.S.R. 0 ::::; would have accomplished little of stra ..J tegic military value. After the heaviest � en of the anti-ICBM strikes considered by w the Defense Department, more than 200 i= ::::; e{ 10 ICBM's would survive: an overwhelm l- e{ ing retaliatory force even if one ignores u. the SAC bombers, the missile subma u. 0 rines and the thousands of U.S. tactical a: w nuclear weapons deployed overseas and aJ � on aircraft carriers. It is therefore at ::J least misleading to suggest that a suc Z 5 cessful and strategically effective coun terforce attack could be carried out with low civilian casualties.

major danger associated with a poli A cy reorientation that emphasizes preparations for actually waging a limit ed counterforce war is that it would tend to undermine the stability of the strate FATALITIES estimated for five postulated Russian counterforceattacks are shown: one gic balance. Flexibility is one thing and one-megaton airburst on each U.S. ICBM silo (A); the same attack with surface bursts (B); an efficient hard-target kill capability is two 550-kiloton warbeads per silo, one airburst and one surface burst (C);two three-megaton another. Flexibility is inherent in the warheads per silo, one airburst and one surface burst (D); a "comprehensive" attack, with two 46 wide range of U.S. strategic weapons, one-megaton surface bursts per silo and with airbursts over all Strategic Air Command bases and the two ballistic-missile submarine bases (E).In the last three cases the shelter pos which are targeted on a variety of urban, ture shown in the iUustration at the top of the page is"degraded" by 25 percent and March industrial and military objectives. Any winds are assumed instead of August winds. Also in the last three cases Defense Department one or any 100 of these weapons could evaluated effectiveness of attack: 42 percent of the ICBM's destroyed(C); 80 percent de be launched selectively. Furthermore, stroyed (D); 57 percent of the ICBM's destroyed as well as heavy damage to aircraft on each missile or bomber has multiple tar- ground or flying within eight miles of a base and to submarinesin port and base facilities (E).

35 © 1976 SCIENTIFIC AMERICAN, INC get options. The new Command Data Buffer system currently nearing comple tion makes possible the remote resetting of targets in the on-board computers of Minuteman III missiles from launch control centers in 36 minutes. As a result of all this flexibilitythe U.S. also already has a substantial coun terforce capability even without highly accurate warheads. There are, for exam ple, "soft" military targets such as air fields and submarine bases that could be selectively destroyed with a few war heads. Even hard missile silos could be destroyed by hitting each one with a number of Minuteman missiles. The Defense Department nonetheless wants more: the ability to deliver counterforce strikes efficiently and with high confi dence against hardened Russian ICBM silos. As Schlesinger put it in his 1976 appropriation request: "I believe we should improve our hard-target kill capability so as to have higher confi dence of executing limited hard-target attacks." Indeed, the U.S. is currently progressing toward that goal with fund ed programs. These developments clash directly with the need for strategic stability. A U.S. missile force with multiple inde pendently targetable reentry vehicles (MIRV's) or with the maneuverable re entry vehicles (MARV's) now being de veloped, and with a demonstrated com bination of very high reliability, very accurate guidance and high-yield war heads would suggest to Russian leaders the possibility of a U.S. preemptive strike against their ICBM silos. It would further suggest to them that in a time of confrontation they should not be caught with their missiles in their silos, that at such a time they should either strike first or adopt a "hair trigger," or launch-on warning, policy. The same arguments apply with the U.S. and Russian roles reversed. The current national debate indicates that there is widespread con cern, as there should be, about the possi bility that the U.S.S.R. might be devel oping a hard-target counterforce capa bility, particularly in view of the larger size of the Russian ICBM's. To be sure, it is impossible to envision a disarming first strike that would really threaten the retaliatory capacity of the U.S.S.R. (or of the U.S.), if only because missile submarines at sea and bombers in the air or on alert are not subject to destruction in a preemptive attack. In order to maintain a stable strategic envi ronment such as the one that now exists for the two superpowers, however, there should be neither a real nor a "per ceived" vulnerability of any major com ponent of the strategic deterrent forces on either side. (From the Russian point RUSSIAN SHELTER DESIGNS, from a 1970 U.S.S.R. handbook, are for simple structures to be built by people "using available materials and their own labor." A dugout (top) in firm of view this is true in particular of the clay soU isroofed by rows of fascines(bundles of brushwood, canes or reeds) covered with land-based ICBM component, since it compacted clay and 30 inches of soU. Rings of fascines are required in looser soU (bol/om). constitutes a much larger fraction of

VENT ILATION

WINDOW WDOD.BABBI.EB A WINDOW

U.S. SHELTER DESIGN, redrawn from an illustration published order to provide adequate fallout protection in a basement that is by tbe Defense Civil Preparedness Agency, is for an "expedient shel only partially below ground level it is necessary to put a 12-inch lay ter" intended primarily to accommodate evacuated populations. In er of earth overhead and to pile earth against exposed basement walls.

their deterrent power: roughly 75 per ons extensively and for the U.S.S.R. to wars in Asia. Yet the armed nuclear cent compared with 25 percent for the refrain from responding in kind. truce has persisted. Why has neither side U.S.) The deployment of missiles with Neither side has yet developed weap launched a single one of the thousands hard-target capability would therefore ons designed specifically as hard-target of nuclear warheads that each has had create tension, because each side would killers: weapons that have a high proba deployed? Surely it is because of the fear that such deployment might lead to bility of destroying a hardened military overwhelming fear of political leaders the possibility of an effective first-strike target, such as an underground silo, with and citizens on both sides that once a threat against its force of silo-based a single warhead. Research-and-devel nuclear weapon is detonated there will ICBM's. The fact that formidable tech opment programs directed toward that be an answering detonation, with subse nical and operational difficulties,such goal are, however, funded in this year's quent exchanges escalating until both as the fratricide problem, lead many U.S. defense budget. Before both coun nations are destroyed and hundreds of people to challenge the feasibility of tries are committed further and perhaps millions of people are dead and dying. achieving such a capability is almost be irrevocably to reciprocally stimulated The issue created by the new emphasis side the point; there would still be seri and mutually reinforcing programs for on a selective, hard-target counterforce ous concern about the ability of land developing such weapons, the hard strategy accompanied by intensive civil based ICBM's to survive a preemptive questions should therefore be faced up defense efforts is whether or not there is first strike. to. Do we really want or need them? any real prospect of escaping this "bal What is the value of being able to de ance of terror." Should the assumption US. officials recognize the danger of stroy an enemy silo (which may be emp that a general nuclear war is prevented • seeming to threaten Russian retal ty by the time our warhead arrives) in by the certainty of mutual destruction iatory capacity, and so they couple pro response to an attack on our own silo? If be abandoned in favor of the objective posals for an improved hard-target kill a small response is wanted, will not an of fighting, winning and "surviving" a capability with announcements that de air base or a naval base or a military limited nuclear war when the evidence ployment of new offensive weapons storage depot do as a target? Is not our indicates that even a limited war would would be limited, at least for the time current broad flexibility adequate? Will cause many millions of fatalities? being. But can one acquire just a little hard-target counterforce weapons make In the 1960's the U.S. adopted a stra hard-target counterforce without bring a compelling military contribution to tegic policy giving top priority to the ing on the ill effects of a lot? After all, it national security or does their justifica prevention of nuclear war through de is no more than the fear of a possible tion rest solely on ephemeral politico terrence rather than to preparation for future Russian ICBM counterforce strategic argument? fighting nuclear wars if -deterrence threat against U.S. Minutemen that has We have argued that such weapons should fail. Since then weapons technol been cited in support of the ongoing pro would complicate the problem of main ogy has progressed, so that new and grams for improving U.S. missiles. It taining strategic stability. It would more sophisticated kinds of limited has been argued that we must be able to therefore seem that it would serve the counterforce strikes, including attacks respond in kind against each and every security of both the U.S. and the on hardened military targets. can be se perceived potential threat. Schlesinger U.S.S.R. to avoid their development and riously considered. The political reality said that there should be "no perceived deployment. A significant precedent for of deterrence. however, remains un asymmetries in levels or capabilities of restraining new weapons in the interest changed. New technology and new force-conventional or nuclear." of stability is the treaty, negotiated in strategy do not significantly reduce the The danger in this logic is that 'we will the first round of the strategic-arms limi risk of all-out nuclear war breaking out almost inevitably find our own develop tation talks, stringently limiting anti once the first nuclear weapon has been ment program triggering a Russian ballistic-missile defenses. Now again the fired. commitment to the very program we U.S. and the U.S.S.R. each have a crit It is important to recognize that once fear (and vice versa, of course). All prec ically important opportunity to limit the nuclear firebreak has been crossed edents, including in particular the histo their traditional technological arms the decision to keep a war limited is no ry of MIRV deployment on both sides, competition by restraining the testing longer in the hands of one side alone; it indicate that once the technology has and deployment of new weapons de has to be made by both-Or all-partici been developed and tested for attacking signed to destroy hardened ICBM silos. pants in the conflict.As Secretary of hardened counterforce targets with high State Henry A. Kissinger wrote in 1965: confidence, the dynamics of the nuclear n the three decades since Hiroshima "N 0 one knows how governments or arms race will take over and make it I and Nagasaki there have been many people will react to a nuclear explosion difficult if not impossible for the U.S. to crises involving the two superpowers. under conditions where both sides pos refrain from deploying the new weap- and the U.S. has fought two major land sess vast arsenals ."