' COl133628 ED I FOR RELEASE DATE JAN 2005 -- - b -1 S _5 '_ C - R -E '- T I '--_ _----'I b 3 CENTRAL TSff - INTELLIGENCE B5929-e AGENCY OFFICE OF NATIONAL ESTIMA'lES o March 966 MEIoKlRANDUM SUBJECT FOR DIRECTOR THE Use of Nuc ear Weapons in the Vietnam War CONCLtBIONS A Use of nuc ear weapons by the US in the Vietnam war llOuld be one of the most important events of modem history World reactions llOuld be affected to some extent by the circumstances in which the US resorted to their use and the targets attaclted But almost independent of these factors 'II luld be a widespread J and fundamental revul sion that tbe US bad brol en the 20-year taboo on the use of B nuc ea r weapons Amona the consequences llOuld be intense agitation in Japan probably ead1na to a restriction on US use of Japanese facUities and possibly to denunciation of the US-Japan defense treaty probably some pro iferation aece rated momentum toward nuuear accompanied however by intemational pressure for disarmament in the nuclear technical ities of verification fie d Q with scant patience for the probab reBo ution of condemnation in the UN and a marked d lJni nution of such public support as US pollcy in Vietnam now has - T- P S E-C-R-E-T I'-___ II - Ezc from downgr de sification C01l33628 C It is possible that once the US had used nuclear weapons the Chinese Communists might move to disengage but we think it more likely that they would not do so but would hope that accumulating US losses and mounting world pressures would force the US - Q back down secondary role The DRV would have been reduced to a 1be USSR lo Quld act vigorously against the US on the political and propaganda front we do not believe that it w luld enter the war or support the Chinese with nuclear weapons DISCUSSION I SCENARIO 1 It will be argued in this paper that foreign reactions to llS use of nuclear weapons in the Vietnam war would be determined far more by the fact that the weapons were nuclear than by the circumstances in which they were used or the provocations which might have led the US to use them Nevertheless the circumstances w luld make some difference at least in certain quarters The following short list of conceivable scenarios begins with one in Which US use of nuclear weapons would appear least justifiable in the eyes of the world generally and least in accord with Communist expectations and proceeds to the one which is at the other extreme in these respects - 2 '1_0 P S-E-C-R-E-T C01133628 -6-F SsB-C-R-E-T L-L_ _ --'I - a The military situation in South Vietnam remains essentially as at present the US employs nuclear weapons out of sheer frustration at its inability to obtain any decision by conventional means b The US invades North Vietnam either overland or by amphibious assault or both the Chinese COIIJIIlunists intervene in large combat force either overtlY or with volunteers and the US forces in North Vietnam find themselves threatened with destruct l on 0 Tbe US does not invade North Vietnam But the PAVN plus Chinese COllll1unist ground forces launch the largest scale overt invasion of South Vietnam of which they are capable across and around the demilitarized zone 'nJey may also come into northern Laos in strong force m and South Vietnamese forces may or may not be seriouslY endangered in any event a new phase of the war is a pened by Chinese and DRV initiative d 'nIe area of conflict is expanded by Chinese Communist initiative involving invasions of Laos Thailand and perhaps Burma e 2 The Chinese COlll1lunists thelI ilelves first use a nuclear weapon Neither the first nor the last of these scenarios appears worth serious consideration they are both so highlY unlikelY as to be virtually out of the question and they are included only to illustrate the possibility of situations different from those which we shall discuss therc U'C Within each of the three middle scenarios no doubt a large number of possible attendant circumstances which would have some bearing on the situation and might modif'y to - 31-8 P S-E-C-R-E-T - C01133628 -o-r G FcC-R-E-T '---__-'I - some smaLl degree the judgments which the world made of the US nuclear response and alter the reactions to It Because the effect of such variations would almost certainly be minor it does not seem useful to attempt to explore any of them in detail The discussion which follows aPPlies principally to situation c a large-scale Comnunist i wasion of South Vietnam -- but we have included some references to the differences in reaction which might be expected in situat ions b or d II REACTIom IN THE NON-COMMUNIST WORLD 3 In the non-Comnunist world there are a g od many people who neither 1mow nor care much about nuclear weapons and would not react one wa r or the other i f the US used them in Vietnam particular so long as the danger seemed remote from thelI Selves There are governments which whatever their public pronouncements on the subject would in the light of their particular national interests be glad to see the Chinese Communist regime destroyed by this means There are also individuals and governments who would consider the United states weak if it allowed substantial numbers of its armed forces to be destroyed without attempting to save them by the use of nuclear weapons And there are some who would consider the United states foolish to accept defeat or even compromise in the Vietnam struggle without having recourse to its most formidable element of military power - 4 - T-O-r S Fe E-T '--_--'I - C01133628 -O-P 3 E C H-E-T 1-1_ _---'I - 4 Granting these and perhaps some other exceptions there is in the field of internation affairs probably no more universal opinion than that which holds the use of nuclear weapons to be abhorrent Any use of nuclear weapons by the US in the Vietnam war would be viewed as DJ1lOng the most fearful and fateful events of modern history Worll reactions would be affected to some extent by the conditions under Which the US resorted to their use and the kinds of weapons and targets involved But aJ m ost independent of these factors would be a fundamental revulsion that the US had b roJ en the 20-year taboo on the use of nuclear weapons 5 'llie use of atomic bombs against Japan in 1945 is still condemned by many not only abroad but withi l the US Most informed opinion however recognizes that it was intended to hasten the end of a long and bloody world war Most important it is seen as a bad moment of history that occurred nearly a generation ago and must never be repeated 6 Over the years world opinion has been Generally surprised and relieved to discover that the US-Soviet nuclear race rather than precipitating a war between the two powers has tended to make - 5- 1-0 rL__ _-_E_-_C_- JR-E-T i - C01133628 'T-O-r Ii E C-B-E-T '--__--'I such a war unthinkabl e Nucl ear bombs and warheads thus tend to be l ooked upon as weapons which wil l never be used except in a worl d bent on sel f-destruction It hlls come to be fel t that the chances of a nucl ear hol ocaust have significantly receded in recent years because the two super-powers are l ed by responsible governments which are prepared to go to great l en8ths to see that nucl ear weapons Will never again be empl oyed 7 Their use in Vietnam regard1ess of the circumstances woul d send a wave of fear and anger through most of the inf mned worl d The general feel ing woul d be that once the taboo had been broken there woul d remain no effective barrier to expanded use of such weapons Peopl e woul d fear that the Communists woul d respond in kind i f they had or coul d acquire a nucl ear capabUity Behind oJ J this woul d l ie a fear that the use of nucl ear weapons might l ead to a general nucl ear war endangering the worl d at 1arge B Most friends of the US woul d condemn it for having dragged the world into a new and terribl e phase of history in which nucl ear weapons had become the worlting weapons of the times Resol utions of condemnation woul d be introduced in the UN with the l 1kel1hood of winning a majority vote NATO woul d be badly shaken Such public support as US pol 1cy in Vietnam now receives from a number of governments especia ll y in Europe woul d be ended - 6- -'-0 S B-C-R-E-T '-__-'i - C01133628 T-O-f 9 E C-R-E-T A British Government which failed to maJ e a public condemnation of the introduction of nuclear weapons into the Vie1 nam righting would probably fall In JapaJ1 memories of Hiroshima and Nago saki would make the people eSpecially resentful of a second use of US t ucJ ear weapons against Ashns At a minimum Prime Minister Sato would feel compelled to end his support of US policy and in part f cular to restrict the US use of Japanese facilities More HI ely the Liberal-Democratic Party would replace Sato with someone less identifiably pro-US in his views It is possible that under leftist prodding the popular reaction would force a move to close US bases or even to denounce the US-Japan defense treaty lobst opinion in India and the Indian government would strongly condemn the US action though some th Indian leaders would be relieved to see set bacl Chinese Communists and some lOuld be secretly pleased if Chinese nuclear facilities were destroyed The general Indian condemnation lOuld be somewhat reduced if the nuclear weapons were used to stop a ChineGe invasion of Southeast Asia 10 A very limited use of tactical weapons in only the immediate battle area would cause a less violent reaction in sophisticated circles than would the nuclear bombing of Chinese - 7 l-OSF SsB-C-R-E-T - C01133628 - T-O-P S F Q-R-E-T L--I_I - airfields rail centers and nuclear production sites But to much of the world the distinction would not be significant the important thing would be that these weapons had been used at all The circumstances under which the weapons were used have some effcct on reactions 70u1 l also The most severe reaction would occur if the US had i nvaded North VietudII1 case 'b' on the other hand the ne Jative reactions would be reduced if nuclear weapons were employed as a last resort to stop the Communist Chinese overwhelming the whole of Southeast Asia Indeed in this case some positive support would be manifested n Beyond these dil ect reactions there wou 'Jl be other effects having a Growinc impact n the future E re would probably be a wave of international pressure for iDlDediate disarmament in the nuclear field Mlst of this would be awed at the US as the only nation to have used such weapons and there would be little patience with continued L insistence on the need for inspection It is possible however that some of this pressure could be diverted to the Soviets in the form of demands for real and verified disa rmamcnt 12 Yet paradOXically there would probably also be an accelerated momentum toward nuclear proliferation - 8 T 6-p 5 l i C p-E-T A U3 use which C01133628 -O-i 5 E-C-R-E-T - legitimatized nuclear weapons and demonstrated their critical imporcslIce and prMticabUi ty in governments to eel tOd 's wars ould lead flome taey must have such weapons in their arsenal s At the same time the argument 88ainst prolifere tion would lose moral credit and encO llli er cY nical reactions III REACTIONS IF TIlE KEY CQl f lUNIST COUNTRIES 13 CODI unist China The Chinese Communist leaders are quite conscious of the potent nuclear arsenal of the US In adopt in a policy L volving the probability of war with the W they would have considered the possibility that nuclear weapons m1eht be used They miGht have concluded that international and domesti c pressures would prevent the US from using nuclear weapons IDlder an y conditions short of a direct survival thre to its national They could not be certain of this however and their plans would ha ve incl uded courses to follow if nuclear weapons were used 14 It is possible that once the US used nuclear weapons the Chinese miGht move to disengaGe particularly i f they had not expected the US to do so We think it more likely however that once cODlllitted the Chinese 'WOuld attempt to continue in spite of nuclear weapons In the belief that they could eventual ly prevail - 9 - -O-f S F G-R-E-T '---_--'I - C01133628 T d-p G F-9-R-E-T '---_---'I they would probably press on acceptinG the military consequences while tryillB to minimize them by dispersa1 c ose-embrace batt1efie d tactics and an intensification of guerr UJ a -n'are behind the US 1nes pro lIG ibey would hope thus to where accmllulatillG US force the 5 osses the and llIOuntillG strug e wor d to the point pressures woul d m to back down ihp USSR M lscow would be a1 a nned at the prospect of continued esca1 ation which might force it into a nuc1ear confrontation with the US It wo d talce steps on 1ke ihood of such a deve o pment on the proPaBanda and po ttica1 front reduce the It strivi l wo d fronts to act viBorously to generate sufficient international pressure in and out of the UN to force the US to back from its esca1 ation ihe Soviets would probably fee co llClJ ed to warn the US that the tlSSR would support China with rn JJ itary aid At the same time however they would mal e it l killG not to count on Soviet certainly not provide any 6 nuc ear nuc ear weapons c ear hey to wo d a1 most weapons to the Chinese With the war havin3 expanded to the point where the Chinese were directly invo ved and nuc ear weapons had been introduced the DRV would have been reduced to a secondar y ro e he PAVN VC wo d retain a significant capability in the - O - L I_ _ _--'I - COl133628 T-Or -E-C-R-E-T '----_--JI - South but in the biG pictw e they would have become an adjunct of the Chinese forces In thp event that the use of nuclear weapons so ala ' '1llcd the DR'I as to lead it to wish to quit the war the Chinese involvement and presence would probably have foreclosed this option rI Thcy cr ll d end the war only if Pelting concurred LONGER 'lERM IMPLICATIONS 17 If the tactical use of nuclear weapons succeeded in turninG back the Chinese and helped lead to a quick and advantageous settlement in Vietnam there would be many Gains for the US to set against the losses mentioned above lklthinG succeeds like success and many would forgive the US once the danger receded Asian allies of the US would feel much more secw e against Chinese encroachments Pelt1n badly set bacl would lose prestige and this might lead to a reappraisal of the leadership by the masses and the yOllll ler party leaders The Soviets would lain new fear and respect for the US hard liners their conviction of the danger of wars of national liberation would be confirmed At the same time those in the USSR who advoca te grea tcr stress on military development and are unenthusiastic about detente would have their hands strenGthened - II - o IC01133628 o - I- T-O f __B_F_-_C_-_R- J-E-T 18 If' the US used nuclear weapons with some persistence and still failed to turn back the Chinese or bring a quick end to the ar the results would be serious indeed The comparative impotence of' the US end of' its most vaunted weapons in coping with a revolutionary struggle would have been demonstrated to Peking's oatisfaction and advantage At the SIlJlle time the US would poy the whole political cost of haVing used these weapons in the first place 19 There remains of course the question of the consequences of net uning nuclear weapons and of accepting a military disaster perhaps extending to loss of the war which these weapons might have averted Such a development would have profound implications f'or the standing of' the US in the world and for the balance of power in Asia Examination of these implic cions however would involve consideration of the whole subject at US objectives and policies in Southeast ASia and does not come within the scope of this paper FOR THE BOARD OF NATIONAL ES'l IMATES ABBJr blttl'h Acting Chaiman - 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