1 i'yr 0191 No J C 3 1691 10 SPEC IAL DISTRIBUTION 29 December l947 Pogee_25 - 142 incl NOTE the 654305 R03 cmm 0 4 - JOINT OF Email on PROPOSED RELEASE OF AN VERSION OF THE FINAL OF THE JOINT CHIEFS OF STAFF BOARD-ON OPERATION THE RELATEDV REIEASE References o 15 11 3 31 1691 7 c C S 1805 a E-4 1 Enclosure contains a letter dated 18 December 19% A from Dr Karl T Compton Chairmen Joint Chiefs of Staff r a - 3 Evaluation Board in reply to the memorandum 1n Enclosure 3 to 3 0 8 1691 7 2 The Director Joint Staff recommenoe that in order now x to place the matter before the President Enclosures and be forwarded to the Secretary of Defense undee cover of the memorandum in Enclosure 534 uu e 2 w G LALQR J H IVES Joint Secretariat DESTRIBUTION Aom Leah DEC 31 117 AM Gen Eisenhower GSA Gen Spoatz CSAF Denfeld ONO Gen Collins Army A m She mon DONG Gen Wedemeyer Dir Army Gen Worsted Air Gen Weylond Dir Air Gen Grueother Secy JCS- I 7 qq s-mwm DECLASSIFIED ENCLOSURE R-A 1 Following the submission by the Joint Chiefs of Staff Evaluation Board of its final report on operation Crossroads the Joint Chiefs of Staff received from its Board a version of its report which the Board considered suitable for release to the p blio together with a proposed press release This extracted version _was identical to the Board s final report except for deletions made by the Board in the nationel interest 2 The extracted version of the report and the proposed press release have been considered by the Joint Chiefs of Staff and the Atomic Energy Commission Since portions of the report and proposed press release contained restricted data as defined by the Atomic Energy Act the Joint Chiefs of Staff upon recom mendation of the Atomic Energy Commission made certain_dele tions Additional deletions were made by the Joint Chiefs of Staff in the interest of military security 3 The revised extracted version of the report was then form warded to the Chairman of the Joint-Chiefs of Staff Evaluation Board under cover of the enclosed memorandum Enclosure b0 J C S 1691 7 4 Having now received-a reply from the Chairmen of the Joint 'Chiefs of Staff Evaluation Board Enclosure the Joint Chiefs 0 of Staff recommend that the Secretary oi Defense submit the revised straoted version of the report Enclosure and the proposed press release Enclosure to the President for his consideration and decision as to whether or not he will release them to the public romp swim 5 The Joint Chiefs of Staff consider that from the military point of view the enclosed revised extracted version of the report and the proposed press are now suitable for public release However the Joint Chiefs of Staff desire-thet-the Secretary of Defense invite the President s attention to the bracketed portions of the report which the Joint Chiefs of Staff consider basically of a political nature and thus beyond their purview se that the President meg give consideration to these bracketed pertions before releasing the report to the public 6 If the President e decision is to release to the public the revised extracted vereion of the Board's final report Enclosure after eeleting the bracketed portions thereof and to approve the propose prese release EnclOsure the Joint Chiefs of Staff desire that the Secretary ef'Defense invite the President s attention to the recemmeneetione by the Chairman of the Joint Chiefs of Staff Eveluetien Board in the footnotes en pegeleQandl25c the report in'whieh recommendations the Joint Chiefs of Staff concur I 4' DECLASSIFIED A MASSACHUSETTS INSTITUTE OF F1TECHNOLOGY Office of the President December 18 19% Joint Chiefs of Staff weshington 25 D C I Att Fleet Aemirel William D Leehy Chief of Staff to the Commander in Chief of the Armed Forces Subj Release of final report of the AJoint Chiefs of Staff Evaluation Board for Oberetion Crossroads Deer Admiral Leehy Returned herewith is-the press release proposed by the Joint Chiefs of Staff which you sent me with your letter of 14 November 1947 Enclosure to J C S 1691 7 Congestion of engagements which were shifted to this fall to clear the woy for my serVice on the Universal Training Commission lest spring have made it impossible for me to study the proposed release end reply to you at on earlier date It seems to me that your proposed handling of this matter is skilfully eesigned end the explenetory note in which you hove explained the deletions and modifications is satisfoctory except rthet_eccurecy would seem to reguire on entitionel phrase as indicated on page192 if the Fresident decides to delete the bracketed paragraphs on pages l3l 139 also Enclosure B pages If the President wishes the bracketed paragraph on pagei to be_deleted then I believe that the argument requires the substitution of the word attacks in plece of the words prepares an attack Thus this rerogrenh woulo reed If he attacks overwhelm him one destroy his will and ability to make war before he'con inflict significant damage upon us Unless such e stotement is included the whole section 7 becomes very week i 7 i DECLASSIFIED uthority gt ins actuhl deletions include actual information and references which I think our Board would all agree should not-be published Certain other deletions I find it a little difficult a to understand because they are matters which have already seen C12 publiShed in officially cleared publications Nevertheles I do not consider their deletion objectionable from our point of View because it is the general story rather then the quantitative detail in which the public would be interested and this general story is told in the-report as modified Furthermore we realize that it may be undesirnble to emphasize iurther certain points even though these points have in the past been publicly dis cussed With reference to the sections which you have bracketed in order that the President moy have then called to his attention and may make the decision as to propriety of release through I the Joint Chiefs of Starr this appears to me to be approprinte Part of our objective in including these items in our report will have been accomplished by the very feet of bringing them specificelly to the President's attention although we have felt that it was also a part of our duty to have these matters brought to public attention While this was the unanimous judgment of our Board we have various individual opinions regarding the timing and method of any such public statement For example it is my personal judgment that the present construction of the Atomic Energy Commision should not now be tampered with because the transition from Manhattan District to Atdmic Energy Commission management and the uncertainties of the period during which the Atomic Energy Commission legislation'was under discussion were-detri mental to the effective and vigorous prosecution of the atomic energy program I do not believe that-another period of un- certainty tre sition should be interjected just at this time when the new management of the program seems to be making encouraging progress My colleague Bradley Dewey may or may i DECLASSIFIED x uthority i 1 5 a a not wholly agree with me in this but I do know that he feels strongly an obligation to discuss this matter and even more strongly an obligation to let the public know that our Board feels that the danger of sudden and devastating attack _made possible by the atomic bomb and other modern techniques requires a reconsideration of the traditional conditions under which we Mr Dewey has have deemed it proper to order a counter attack the present intention of making a public statement along these lines before long I mention this Wibh his permission In sumcary therefore I express aporoval as Chairman of your Evaluation Board of the procedure which you have here ens or additions of phraseology proposed with the two modificat indicated above in the secondI paragraph I feel that I should comment a little more explicitly on t the uestion of nossiole nublic statements by individual members of the Evaluation Board as differentiated from an official release of our report by the-Joint Chiefs of Staff we all 1 recognize the propriety of a Top Secret -clessification by the Joint Chiefs of Staff for any document or_statement for which the Joint Chiefs of Staff are responsible There is also no question about the propriety of any appropriatela assigned classification which may be given to factual information regarding a reopen its effects or its use On letters oi opinion regarding general not consider that report is binding public policy hoWever members of our Boaro do J- ton attached I the Top Secret classificat On such matters I believe-that their actions will be based entirely on their individual judgment conscience and sense of propriety y Bradley Dewey and I had specific understandings with Secretary horrestal before we accepted appointment to the Evalun ation Board that we Should retain the privilege of commenting far as 1180 publicly on any matter related to the tests except military secrets are involved In other words we were unwilling W s-hm not wholly agree with me in this but I do know that he feels strongly an obligation to discuss this matter and even more strongly an obligation to let the public ow that our Board feels that the danger of sudden and devastating attack wade possible by the atomic bomb and other modern techniques requires a reconsideration of the traditional conditions under which we have deemed it proper to order a counter attack Mr Dewey has the present intention of making a public atement along these lines before long I mention this with his permission In summary therefore I espress_approval as Chairman of your Evaluation Board of the procedure which you have here with the two mooifications or additions of phraseology 5 indicated above in the second paragraph 2 I 0 a feel that i should comment's little more expliCitly the question of possible public statements by indiVidual memcors 3 - rig of the Evaluation Board as differentiated from an official 3 i a a r1 a ind i_ release of our report by the JOint Galois ox Stafi we all t I recognize the propriety of'a Top Secret classification by the Joint Chiefs of Staff for any decunent or f or which the Joint Chiefs of Staff are responsible _ There is also no question about the propriety of any aparopriately assigned classification which may be given to factual information regarding a weapon its effects or its use On setters 0 opinion regarding general public pelicy however members of our Board do not consider that the Top Secret classification attached to our report isbinding On such matters I believe that their actions will be based entirely on their individual judgment conscience and sense of propriety Bradley Dewey and I had specific understandings with Secretary Forrestal before we accepted appointment to the Evalu 54- ation Board that we Should retain the pr vi ege of commenting -n so far as publicly on any matter related to the tests except 1 itary secrets are involved In other words we were unwilling 99 - Enclosure A E31 5 3 gs U555 5 A 'ebcve limitatiene as the actual find If -- - to let cureelvee be put in a pceiticn because of service on the an Evaluation Beerd whereby we woul be prevented from expressing cutselves freely on any matters of public policy as long cs such did not disclose factual er plane Mr Dewey s understanding with the Secretary was that he was free to mention and discuss the findings cf our Board subject to the anc recemmendntiene e the Beard My own independent understanding was that I would be free to express my pereennl cpiniene en ench matters at any time but withcut speaking officially fcr'the Boned I feel I ewe_it to my colleagues and myself to clarify our position on this point lest there be any mieunder standing Very sincerely yours Karl T 4 5 v- DECLASSIFIED thority w ea APPENDIXLTO emetosoee_ sf THE OF DEFENSE visnmvev0m 2 October 1948 MEMORANDUM FOR Rear Admiral R H Hillenkoetter Director Central Intelligence Agency SUBJECT Proposed Director of Central Intelligence DirectiveVE l 1 By your memorandum of 7 June 1948 you referred a proposed 001 2 1 Implementation of Coordination of Collection Plan to me in accordance with paragraph 3 of NSCID No l for solution of the prObled raised by the non-concurrence of the Navy Department in the proposed directive as evidenced by its suggested additions thereto 2 I have considered this matter and have determined that it would be undesirable to amend the proposed directive by adding the two additional provisions suggested by the Navy Department 3 Enclosed for your information is a copy of a memorandum which I have sent today to the Secretary of the Navy and the Secretary of the Air Force advising them of this decision and of my interpretation of the proposed directive That memorandum also sets forth my desires as to two specific matters in the field of air intelligence JAMES FORRESTAL CONFIDEETIEL ENCLOSURE EVALUATEON of the ATOMIC BOMB as MILITARY WEAPON nThe Final Report 2 'Df the Joint Chiefs of Staff- Evdluation Baar fa - i-x LS 1 Operation 1 - ijJune 194 WM Wa wamy g he 4 2 DECLASSIFIED tyuun Q liimm I Authori Explanatory Note of the final Ln The following pages contain the salient portion report of the Joint Chiefs of Staff Evaluation Beard The Beard has seen fit in the national interest to delete certain paragraphs Other deletions have been made by eempetent eutherity in ascendence with the provisiens of the ATOMIC ENERGY ACT The Joint Chiefs of Staff have made fuethef eeletions in ran the the interest ef security of military date derived i Cressreeds D sts or otherwise in the national interest at the ef higher authority % This clause to be added at some suit a thle equivalent in case the President Wishes the bracketed graphs to he deletej DECLASSIFIED JOINT STAFF EVALUATION BOARD Dr Karl T Compton Chairmen Mr Bradley Dewey Mr T F Fertell Gen W Stilwell USA Lt Gen A C Wedemeyer deceased USA appointed ta succeed Gen Stilwell Lt Gen L E Brereton USA- Vice A miral John H Heev Rear Admiral Ralph matey Co Mr Russ Symontowne Dr Thornton Page Col Robert G Butler USA Maj Glen W Clark USA - Technical Aide te the Board Secretary te the Board 1 Robert G Butler Jr USA Acting Secretary to the Board_ rTABLE OF CONTENTS PART I IETTER OF PART II PARTICIPATION IN THE PART CONCLUSIONS AND RECOMMENDATIONS Section'Two PART IV TEXT OF THE REPORT 'S ction One OPERATION 0302320132 Section Two GENERAL -Section Three UPON SHIPS One Damage Two Naval De ign an Training I 5 1 Section Four EFFECTS UPON THE HUMAN ORGANISM Section Five USE OF BOMB IN NEW One Genewal Defenae Two Research Develament and Stockpilin Three Measures of Activa Four sziVG Atomic Warfare Six Consi eratian of Seven a Effectivanass of the Bomb Against I 0 Eight - Payohological Atomic Warfare Nine - Cantinuous Review of Targe J- L #30 Ten Concluding L TAGT 107 108 110 113 116 118 118 120 121 124 125 127 129 47129 131 133 135 138 138 A DECLASSIFIED i Auth Acknowledgments In the preparation of this report the Board availed itself of the services of Rear Admiral W S farsons US Chairman JOINT CROSSROADS COMMITTEE and found his advice and assistance of great value In addition members of the Operations Evaluation Group Office of the Chief of Naval Operations were of service to the Board _ Its members are especially indebted to r Edward S Gilfillan Jr Technical Director of JOINT CROSSRORDS to Dr Arthur grown of the and Commander Roger Revelle USNR Oceanographic 'Assistaht to the Director of Ship Material and Cowordinator for Oceanography to the JOINT CROSSROADS COMMITTEE for material especially prepared for this report Rear Admiral T A Solherg USN Director of Ship Material and Capt F X Forrest USN Bureau of Ships were generous in their assistance Col Stafford L warren USA MC Radiological -Sefety Adviser OPERATEON CROSSROADS was of great assistance to the Board in his field Credit for material taken from the reports of others is contained in the text of this report J This repert was Dragsred under the direction of the Board bwar Russ Expert to the Civilian Members of the Board sn Chief 9f its Secretariat Mr Symantowne had the assistance of Dr Tharnton Page Col Robert G Butler USA and Maj Glen W Clark USA Technical Ai s and Consultants to the Military and Naval Members_of the Board a- - 106 w Enclosure - DECLASSIFIED uthority 9 I Bradley Dewey Letter of Transmittal The Joint Chiefs of Staff washington D C Subject Final Report JCS Evaluation Boor Gentlemen Your Board appointed to evaluate the Bikini Atoll Atomic Bomb tests has the hone to trenemit to you its final report In accordance with our Directive this olessi fled e tz TOP SECRET In order that the Joint Chiefs of Staff may make this report public the Boer has yrepered a revision from which Certain motter_has been delete Prior to toe tutu lieotion of this revision it will beneoeesery that classi'ied factual material be deletee by the Joint Chiefs of oteff we regret the death of Gen Joseph W Stilwell on original member of the Board who took an active part in its early Geliberetions Hie dutiee'heve been capable discharged by Lieut Gen A C wedemeyer waom you oopointee to Succeed him - yours 9 nee dm Ralph A Ofetle USN Lt Gen A C Wedemeyer USA Lt Gen L H Brereton USA Thomas F Ferrell Karl T Compton Chairmen Vice Adm John H Hoover USN DECLASSIFIED i - PART II The Board's Participation in the Tests 1 Under date of 27 February 1946 William D Leahy Fleet - Admiral United States Navy Chief of Staff to the Commander in Chief of the Army and Navy transmitted a memorandum for the Chairman Evaluation Board AtomiC'Bomb Tests with the subject Instructions to Evaluation Board for the Atomic Bomb Tests This memorandum charged the Board with two broad functions To be available for advice to the Task Force Com mander during the preparations for the tests To examine and evaluate for the Joint Chiefs of Staff the resalts of the tests 2 There followed instructions for the preparation of two preliminary public reports one to be submitted immediately upon the conclusion of each test 3 Concerning its final report this memorandum informed the Board that it should include pertinent comments on strategy tactics and technical information valuable to the national interests of the United States 4 The memorandum further read The Evaluation Board will be guided exclusively by its own judgment in its evaluations based on the results of the tests Particular attention will be paid in the final evaluation to the strategic implications of the results as well as the factual damage incurred by naval vessels and other material 5 The Chairman acting on behalf of the Board-and with its subsequent approval offered 2 April 19Q6 several suggestions to the Commander Joint Task_Force One with respect to the oil gasoline and ammunition loadings of certain target vessels as well as to instrumentation for the tests The Chairman's observations together with the reply of the Task Force Com mander have been presented previously DECLASSIFIED I Authori EPART II - The Board s Participation in the Tests 1 Under date of 27 February 1946 William D Leahy Fleet Admiral United States Navy Chief of staff to the Commander in Chief of the Army and Navy transmitted a memorandum for the Chairman Evaluation Board Atomic Bomb Tests with the subject Instructions to Evaluation Board for the Atomic Bomb Tests - This memorandum charged the Board with two broad functions I is To be available for advice to the Task Force Com mander during the preparations for the tests it To examine and evaluate for the Joint Chiefs or-Sterr the results of the tests 2 There followed instructions for the preparation of two preliminary public reports one to be submitted immediately upon the conclusion of each test 5 Concerning its final report this memorandum informed the Board that it should include iipertinent comments on strategy tactics and technical information valuable to the national interests of the United States 4 The memorandum further read The Evaluation Board will be guided exclusively by its own judgment in its evaluations based on the results of the tests Particular attention will be paid in the final evaluation to the strategic implications of the results as well as the factual damage incurred by naval vessels and other material 5 The Chairman acting on behalf cf the Board and with its subsequent approval offered 2 April 1946 several suggestions to the Commander Joint Task Force One with respect to the oil gasoline and ammunition loadings of certain target vessels as well as to instrumentation for the tests The Chairman's observations together with the reply of the Task Force Com mander have been presented previously DECLASSIFIED uthority 9 - 4 6 The Board held three meetings in Washington prior to the tests these being on 28 February 26 March and 29 April Its members and staff left'Wsshington for Bikini Atoll 25 June and after Witnessing the tests returned 1 August Numerous meetings and consultations with the Task Force Commander members of Lie staff and civilian experts were held during the tests The Board members were afforded every facility for the performance of their duties and enjoyed every courtesy from all with whom they came in contact Following the tests the Boerd held three meetings in Washington for the yreperetion of this report -These meetings took place 13 and 14 January 1947 ll February and 23 April The Board held its final meeting in Cambridge Mess 24 June PART u Conclusions and Recommendations Section One CONCLUSIONS Note Several paragraphs have been deleted and the numbers adjusted scoordinglr l The Board has reached the following major conclusions 1 if used in numbers atomic bombs not only can nullify any nation s military_effort but can demolish its social and economic structures and prevent their reestablishment for long periods of tine With such weapons especially if em ployed in con unction with other weapons of mass destruction as for example pathogenic bacteria it is quite possible to dcpopulste vast areas of the earth's surface leaving only vestigial remnants of men s materiel werks 2 The threat of the uncontrolled use of the atomic bomb and of Other weapons of moss destruction is a threat to'men kind and to Civilization Only the outlawing of all war and the setting up of on adequate international control of weapons a of mass destruction can lift this threat from the peeples of a the world 9 In the absence of sbsolnte'goerentoes of abiding pence i the United States has no alternative but to continue the a I -monufncture end stockpiling of wespons of nuclear fission and to carry on continuous research and development for their im provement and improvement in the means of their delivery 4 The value of surprise in attack has increased with every incresSe in the potency of With the advent of the atomic bemb surprise has achieved supreme value so that an aggressor striking suddenly and uneXpectedly with number- of atomic bombs night in the first assault upon his vital tsrgets achieve such an order of advantage as would insure the ultimate defeat of en initinily stronger adversary I There must be notional recognition of the probebility of surprise ntteck and consequential revision of our trs 3 ditionsl attitudes toward that constitute acts of aggression so that our armed forces may plan and operate in accordance m fwur cashew DECLASSIFIED Authori -i with the realities of atomic warfare Our policy of national defense must provide for the employment of every practical means to prevent surprise attack Offensive measures will be the only generally effective means of defense and the United States must be prepared to employ them before a potential sham Loan inflict significiant damage upon as d 7 6 National defense requirements of the future are only those of the past any aggressor must be overcome with superior force _Bot where in_the past the duty of the President as the Commander in Chief has been restricted '- before formal declaration of war to action only after the loss of American lives and treasure it must be made his duty in the future to defend the country against imminent or iincipient atomic weapon attach I m at m 7 What constitutes an aggressive act or imminent or' insipient attack it is the responsibility of the Congress to define and to redefine from time to time so that it may draft suitable standing orders to the Commander in Chief for prompt and effective atomic bomb retaliation should another nation ready an atomic weapon attack against as in 8 No weapon can be more effective than the means used to Ibring it into_actionagainst the anonyg-hence the necessity for the coordinated development of atomic weapons and weapon carriers and their integration into a series of devices each with a tactical or strategic purpose In the category of weaponmcarrier may be included any means of ultimate delivery such as aircraft guided missiles rockets torpedoes and mines of all types 9 lnseparable from the development of bombs and bomb carriers should be the planning of naval surface and sobwl marine vessels from which atomic bomb carriers may be launched or discharged as well as of land launching devices stationary or mobile and the acquisition and maintenance of land and air bases ll l DECLASSIFIED sax MM If Autho 10 Any target study must include critical consideration of the vulnerability of this country to atomic bomb attack and should lead to the Study of ways and means of reducing this Vulnerability not only by physical dispositions and military measures but by suitable training and-indoctrination of military personnel and Civilian population 11 No specific defense against the bomb exists nor in the current opinion of science is any likely to be devised Such passive defense measures as concealment or massive shielding or belowwground construction may well serve in the case of vitel military facilities but these measures are im- practicable for the defense cr a city and its inhabitants 12 For defense against atomic reopens chief reliance must be upon the prevention or frustration of on enemy attack or _upon immediate retaliatory measures which will overwhelm an enenr and result in the destruction of his power and ability to make war Essential to any plan of defense will be knowledge as to whether potential enemies are in tossession of the means to produce weapons of nuclear fission'end knowledge of their readying an attack So gain this knowledge there will be required an intelligence service with a fer greater effec tiveness than any such service this country hes has in peace or war l4 A correlation of-the sitici'tcct cats with other data C 3'3 g 5 - indicoteS thet ships bodies of troops ere in general unlikely to be regarded as primary-atomic bomb target although in special circumstances they would undoubtedly invite such attack 15 The advent of theseonic bomb hes not eliminated the need for ground see and air forces although it may effect their composition in siZuble degree 16 No result of the Bikini tests indicates the wisdom of any deperture_fron the brinciple that navel ship design should be based upon tactical function Neither did the tests DECLASSIFIED -indicate that the design requirements of ships as dictated by tactical funCtion should be compromised by emphasis upon- additional protection from atomic weapons beyond that degree appropriate to the type 17 Dominance in the ability to wage atomic warfare the lees of which might be fatal to our national life can be re tained only by unflagging effort to hold that leadership in science and engineering which made the atomic bomb possible A rital part of the national defense must be not onlj a prom gram of scientific and engineering research and development in every field involved in bomb production and tactical use but in basic science as well Such a program requires periodic tests of atomic weapons 18 A peace enforced through fear is a poor substitute for a peace maintained through international cooperation based upon agreement and understanding -Bnt until such a peace is brought about this nation can hope'only that an effective deterrent to global war will be a universal fear of the atomic bomb as the ultimate horror in war Section Two - RECOMMENDATIONS Note a Authority 1 Several recommendations have been deleted and the paragraph numbers adjusted accordingly l The Board reComnends 1 That since the abolition of war is the only_absolute protection humanity can have against possible annihilation of its civilization by atomic and other weapons of mass destruc tion the Joint Chiefs of Staff continue to give every proper support to plans for the achievement of an acceptable guaranty of international peace 2 That so long as the world lacks such acceptable guaranties of permanent peace the manufacture and stockpiling of atomic weapons_and fissionable materials be continued by I the United States in each quantities and at soon a rate ofm production as will give to it the ability to overwhelm swiftly any potential enemy DECLASSIFIED 5 That a constant program of research and development be carried on looking to the improvement of atomic weapons 4 That legislation be enacted by the Congress establish ing'new definitions of acts Of aggression and incipient -attack including the readying of atomic weapons against us This legislation should make it the duty of the President 05' the Suited States as Commander in'Chief of its Armed Forces after consultation with the Cabinet to order atomic bomb retaliation when such retaliation is necesery to prevent or frustrate an atomic weapon attack upon as um 5 That the development of atomic weapens and Weapon carriers no so coordinated as to integrate them into a series of devices of specific tactical use and widest military -effectiveness 6 That the conclusion be accepted thatpassive defense dispersion concealment and above or below ground pro tection practical for relatively small facilities is in practicable for urban and industrial areas V17 That studies be undertaken to determine to what extent and in what manner military and other targets of high ism portance can be given adequate protection That studies be undertaken to determine measures for the immediate relief of survivors of atomic bomb attache for the reduction of-nortality by medical techniques 0 for the suitable advance training of military and civilian personnel in radiological safety techniques including f methods of decontamination and for the detolopment of instruments and equipment necessary to the foregoing evident that eariy knowledge Dr s rpotential enemy s production of fissionable material in war quantity and of his readying of atomic weapons for use is of essential valge tc oar defense we maintain an intelligence service with a far greater effectiveness than any such service this country has had heretofore in peace or war da- DECLASSIFIED i uthority I - 3 v flo That tests-of atomic weapons be held Whenever necesn sat is the research and development of such weapons or the tactics of their uss or the training of personnel 'Vfll That the Atomic Commission b requested to re gs soon as possible Bikini test rss lts now classi fied either in a military sense-or under'thc Aet so that certain data will be available to military echelons and other data will be unreStrictsd 12 That the Congress review in the li ht of new con ' 3 8 I mat-luv sidsrations and in the interests of the long term effective ness of the national defense the statement of policy upon which the Atomic Energy Act is_bassd I m n I tyum QLIQQH DECLASSIFIED Authori 1 3PART IV Text of the Report_ Section One operetioh CROSSROADS l The-Board finds from available figures that operation CROSSROADS in the conduct of atomic bomb tests ABLE and BAKER held at Bikini Atoll 1 July and 25 July 19 6 respectively cost the Government an extra expense approximating $50 000 003 2 The tests fully accomplished'twe major purposes 1 They provided data essential to future military planning giving bases for the calculation of the conditions under which the maximum oestructive effects of an atomic explosion will he obtained against various types of lane and water targets and against living organisms Some estiw mete of the amount of this materiel may he gained from the statement that the Technical Historian s summary report elohe consists of 32 chapters while more than 30 000 pages 2 o eeteiled teohnicel reports have been written with others in preparation 2 The tests gave to these upon whom fails the responsim bility of various phases of atomic warfare planning the inceloulehle benefit of a first heed knowledge of the bomb in action an advantage theretcfore possessed by very few persons 3 The tests furnished a vest amount of date of importance in wide and varied military soiehtific engineering and techno lOgicel fields Many of these date remain classified either in e military sense Or as restricted sets under the Atomic Energy Aet Of especial peoeetim A veer are the data relating to nuclear physics medical phases of_redietion including military aspects of radiological safety and those relating to ocean ography meteorology and marine and island biology and geologyEnclosure DECLASSIFIED A Authority i i ability of persennol of all branches cf the armed services and 4 The tests had further value in again demonstrating the civilian personnel to work in efficient harmony setting e pattern for such cooperation in the future I 5 We feel thet the conclusion expressed as to Test ABLE in our Preliminary Report 5 July 1946 may now be stated as a feet _as to both tests that is that the Conditions were well chosen and that the highest skill and ingenuity hnve been used to obtain a maximum amount of date in an unbiased scientific manner The Board feels that the tests were velld_end the Summary Reports therefrem honest and competent 6 In supplenent Report which was made part of our beeond Preliminary Report we called attention to the fact that the ABLE bemh did not burst at the planned exploslon point I 7 Only four ships and craft instead of ten as planned were within relatively close range of the projected pelnt of burst_ end only 18 ships and craft insteed'of 25 as planned were within nediun'renge 8 The tests foenssed the attention of the world upon the_ atomic bomb They were held in the presence of large number' 'ef correspondents Test ABLE 175 Test 75 representine various media of public inferention npproxinetely 2 417 500 words in five languages were transmitted by redio to news papers and magazines 615 radio broadcasts end #01 rsdiophotosr were transmitted 9 Certain pertinent comments and criticisms on the nnetion ing of-the public infernatien plan have been submitted 10 As a result of carefully planned operating procedures and radiological safety measures he casualties resulted from exw plosion or radiation during or after either test and casual ties from other causes were remarkably few i DECLASSIFIED ujkuthori ection PHENOMENA- 1 As the Board indicated in its preliminary_reports on_ Tests ABLE and BAKER the phenomena attending the explosions of both bombs followed to a remarkable degree the predictions made bv oivilian and service experts 2 Data on these phenomena are now in process of analysis and will be available to the Joint Chiefs of Staff 3 One phenomenon of great importance the base surge which appeared after the explosion of BAKER bomb was not predicted Section ON One Damage Results 1 Fer the following brief summary of ship damage resulting' from the bursts of Test ABLE and Test BAKER the Board has drawn upon a large accumulation of data 2 It is to be noted that the targetarray at Bikini did not in either of the tests _represent any ordinary pattern of ship - 9 anchorage used by the Navy except in the case of surplus naval and merchant vessels anchored in Close proximity in dead storage Rather the ships were-arranged in accordance with the CROSSROADS directive to insure graded damage from sinking to negligible and with the hope that a majOrity would remain afloat so that data and instruments might be recovered TEST ABLE - 5 As a result of the air burst an in Test ABLE there was sunk a total of five target vessels in the array of 88 ships and small craft They consisted of two destroyers two transports and the Japanese cruiser SAKAWA In addition six non sunk vessels were immobilized These included two battleships two cruisers a destroyer and a light carrier Ships top hamper exposed electronic equip- ment and instruments were damaged tyuun_g ticll_ - DECLASSIFIED I Authori I I 5 Submarines both surfaced and submerged preved less vulnerable than other types of vessels 6 Although most of the damage was due to blast small fires were started on a total of 23 ships The exact cause of these fires is not clear in eVery case in general they were mincr and because no damage centrol measures were immediately possible fire damage exceeded that which might have been expected had the ships been manned 7 Except for that caused by the minor fires at long range there was little damage to some types of materials exposed on the decks of target ships 8 There was induced radioactivity in the sodium and phos phorus contained in small stores such as soap and matches This effect was of negligible importance and fell off rapidly within 24 hours The lethal effects of radiation are discussed in Section Four TEST 9 The damage produced by the undervater burst of Test BAKER was caused largely by the underwater shock wave Surface waves also caused heavy damage and some damage resulted frem an air 'blast 10 Of the 88 ships and small craft exposed in Test BAKER the burst sank or capsized a total of nine vessels Five nen sunk vessels were immobilized Three other vessels suffered at least temporary serious less of military efficiency The ship figures above include the Japanese battleship NAGATO whiCh sank five days after the esplosion but not the German cruiser PRINZ EUGEN which sank near Kwajalein Atoll almost 7 x jcs 1691 10 113 EnchSure DECLASSIF Authority five months later On both these ships the hazards due to radioactive contamination preVented control of slow leeks In the case of the NAGATO these hazards prevented inspection of damage by boarding parties TESTS ll Correlating the general effects of_the two bomb bursts on ships and material it can be stated 1 Little or no underwater damage was done by the air burst while severe underwater shock end wave motion eocompeny ing the AKER burst did heavy damage to shiss' structure and equipment below the waterline 2 The air blast of Bombms caused extensive damage to superstructures stacks end exposed decks An air blast of lesser magnitude accompanied the detonation of BAKER bomb Extensive damage to above water portions of ships was caused by this blast and by breaking waves which engulfed ships with masses of water 3 Fires were set by the explosion of Bomb A no fires resulted from the second burst TwoaeNevel Design and Tr-ining i No result of the Bikini tests indicates the wisdom of s _devietion_from the principle that ship design should be based upon tactical function Neitter did the tests indicate that the design requirements of ships as dictated by tactical func tion should be compromised by emphasis upon additional proteof tion from atomic seasons befond that degree appropriate to the type 2 The_foregoing considerations should not deter study of measures to minimize the tonb s explosive effects upon - DECLASSHHED Auth I istructure and personnel its radiation effects upon the letter routines organisation bills for ships personnel the development of instruments to estermine the radiation dosage received by personnel GXposed to such radiation and the extent end degree of centamihstion cf structures 3 An impressive result of BAKER was the Contamination cf ships by fission fragments Efforts to decontamihete these ships have thus far emphasized the difficulties of the problem and the necessity for further experiment with Bikini target vessels Techniques develeped for ships Will'epply to the decontamination of-other structures Section THE HUMAN-ORGANISM 1 From military VieWpoiht the atomic bemh s ability to' kill human beings or to impair through injury their ability to nuke war is of paramount importance 2 Thus the over all result of homb s explosieh upon the crew of ship or the inhabitants of a city is of greater ih terest here than an uhlysis of the physiolegical Causes of these results 3 instrumental date and the results of animal experiments tion at Bikini sustsihc the rcpurts of Nagasaki end Hiroshima observers that the effects of an atomic explosieh upon living organisms may be several feld 1 They may he hurhe by the flesh heat cf the bomb 2 they may suffer crguhic ihpeirmeht by external radiation at the instant ef blast 3 They may suffer impairment by rudietieh after the blast from contaminated surfaces or b the-entrance into the body of fission fragments and unfissione materiel nninenrm DECLASSIF IE Authority the Nagasaki blast They may be subjected to the air blast of the sxpiboion and also to the mechanical effects of falling and flying debris and to secondary fires 4 Since it is estimated 92 per cent of those within a radius of 660 yards from the projected ground point of the air burst at Nagasaki were killed by one or more of the bomb's effects a discussion of separate effects Within this range is academic 5 Beyond this range the British Mission to Japan found that the probable order of the ceases of death was 1 burns 2 nechanical injury and 3 gamma radiation 6 0f the utmost significance analysis Of the'Japanese data reveals that had the home s effects been solely radiological the mortality would have been substantially the same 7 The British Mission found that at a range of 1660 yards the mortality rate was #9 per cent while nearly a third of those present within a radius of 2000 yards were killed Even at 2300 yards the mortality rate was 12 5 per cent and a few were killed at the extreme range of 3000yards 8 Flash burn a matter of importance_in the detonation of_ modern explosives occurred at an extreme range of 4600 yards at Nagasaki and it is reported that 95 per cent of those surviting and seeking medical attention snffered from was demonstrated in the Japanese bomb drops and confirmed by the Bikini tests that so brief was the duration of the thermal radiation that shielding even of the most un substantial sort sheets of paper or thin cloth was_sufficient to protect adequately against flash burn even within short range of the detonation In U U 4 y-J 9 The menace of nuclear radiation is present at the instant of explosion and residual radioactivity may perSist for a con siderable length of time thereafter in the immediate vicinity and at greater distance for diminished of time 10 within one Scoond of the explOsion of a bomb in air gamma radiation and neutron emission it has been estimated are_sufficient to destroy human life at distances exceeding 1000 yards and casualties may result at 2000 yards 11 In the case of'a burst at the land surface or at very low altitude there is a deposition of fission products over an area of several hundred yards radius sufficient to be dangerous for several years Neutron emission at the instant of burst results in induced radioactivity in various elements notably sodium This hazard while it may be great for a brief period is secondary in importance to radioactivity from other sources 12 When a bomb is exploded underwater lethal residual radio acitivity assumes an importance greater than the physical damage caused by the explosion Vast quantities of water falling from the explosion column and traveling outward in the base surge and also falling as rain from the cauliflower cloud carry not only highly radioactive fission products but un fissioned material as well l3 'Massive shielding is the only known protection against external nuclear radiation No treatment to nullify the effects of radiation upon living organisms exists nor is there reason to hope that means of prophylaxis immunization or the like can be found So called supportive measures may be effective in prolonging life in certain border line cases and it has been suggested would reduce mortality in Iexposures of less than 400 roentgens DECLASSIFIED 14 This report recognizes the importance of but does not discuss the mechanical effects of atomic explosion upon human beings These effects of the atomic bomb are those common to the explosion of conventional bombs except that in the former case deaths appear to occur at lower peak pressures perhaps because of the character of the pressure Wave Section USE OF THE BOMB IN WAR Ones General Defense Considerations I l The tremendous destructive explosive power of the atomic bomb and the great range of its lethal radiation and residual radioactivity effects combined with the fact that no specific means of defense or of prophylaxis against it exists or is 'likely to be devised make it a weapon capable of decisive importance in war 2 It is apparent that potential enemies of the United States will seek to arm themselves with this weapon and the means to- deliver it The speed with which they will possess atomic weaponswwill be conditioned largely by their scientific _tech nological and industrial ability to solve the problems involved 7 It is common knowledge-that research in nuclear fission is in progress throughout the world 3 Therefore unless there is permanent peace guaranteeing national control of all means of war immediate and continuous preparation for the contingencies of atomic warfare is the part of prudence 4 In the absence of special means of defense against atomic- weapons there are the considerations of conventional passive defense interception of attacking forces and the dise persion concealment or massive protection of targets _and of the positive defense of attack JCS 1691 10 Enclosure DECLASSIFIED Aguthority Wi 5 Conventional defense measures cannot be neglected but there are severe limitations to their effectiveness A fighter air force in being radar networks ample sntiaircraft weapons and proximity-fused missiles might well prove of high value in event of an attack preceded by sufficient warning However the great expanse of this country and the vast number of targets it presents make its adequate defense by such means impracticable The passive defense of dispersion concealment and massive or underground protection is feasible for relatively small facilities of'high military value but could not be employed for extensive installations or cities 7 An adeQuate program of defense therefore must have as a goal the possession of a'snperior striking power and the ability to explode at will with greatest effectiveness such a number of suitable designed atomic weapons as will a Deter a potential enemy from attack or uid If he prepares an attack overwhelm him and destroy his will and ability to make war before he can inflict a u v qh has significant damage upon us 8 The effective military use of atomic weapons is condi Itioned by the possession 0f atomic weapons in adequate numbers p of suitable means for their delivery Of plans for their strateeic use Of bases within range of enemy targets r Two rRosearch Development and Stockpiling 1 No weapon can be more effective in War than the means used to bring it into action against the enem Thus it follows that emphasis Should be placed upon the coordinated development of atomic weapons and Weaponmcarriers and their integration into a series of devices each with a tactical or strategic purpose Substitute' attacks for prepares an attack and include this paragraph if its present form is disapproved r Auth DECLASSIFIED immi orlty 2 Progress reports of agencies engaged in the research-of guided missiles and aircraft for travel at trons and supersonic speeds indicate that in the foreseeable future chief reliance for aerial bomb-delivery at ranges gfeater than 400 miles must be upon conventional aircraft Hence national security will require_unremitting effort to develop present types of aircraft capable of operating at great range under all weather condi tions and in spite of enemy opposition 3 Inseparable'from the development of the bomb end bomb carriers is the development of methods of bomb launching from naval vessels both surface borne and underwater and the acquisition of land air-bases which will best insure bomb delivery to targets distant from continental United States 4 The only means of insuring that we may be in possession of a sufficient number of bombs to overwhelm an enemy intent l_upon attacking us is the stockpiling of bombs and fisSionable materials 5 In the present state of scienbe the processing of these materials is complicated and time consuming It is the lesson of history that new inventions mayat eny time vastly eccelerate presently known methods and thus make it possible for a poten tial enemy of the United States starting late to outstrip us quickly in atomic weapon production 6 The United States cannot retain dominance in atomic warfare u-the loss of which might be fatal to our national life a unless by unflagging effort it netains the leadenship in nucleon physics chemistry and engineering which made the bomb possible Hence a vital part of our national defense must be a program of research and development in-every field involVed in bomb pro duction DECLASSIFIED I Authori 3 7 No development of any weapon or skill in its use can be achieved without periodic tests The phenomenon Of nuclear- fission precludes the explosion of an atomic weapon of less than critical mass and hence_all tests must he iull scale Three Measures_of Active Defense 1 For so long as the United States retains exclusive posses sion of atomic weapons it will_he a matter of our choice based upon political and military considerations of the moment whether theyshould be employed in the event any country has the temerity to_attack us 2 Situations can be envisaged in Which an aggressor with or without the atomic Weapon relying upon various factors of war favorable to him and making difficult our succeSSful delivery_ of atomic bombs to targets vital to his military effort might undertake an attack upon us 3 An enemy geographically remote in possession of only a few atomic bombs might contrive to deliver them in merchant vessels to our chief seaports and without declaration of war to discharge them in our bags and harbors and so cripple us as to permit him to proceed with an act of aggression against a third pover Whose integrity We desired unimpaired 4 The_advent of the atomic bomb has not eliminated our need forgnounds naval and air forces Nor has it lessened the need for overseas bases from Which they can operate effectively The relationship of the atomic weapon to other weapons and means of war in the nation s defensive armament should be the suhject of constant scrutiny in the light of changing conditions and new knowledge Enclosure DECLASSIFIED 5 The_length of time before potential enemies will are themselves with weapons of nuclear fission has been variously estimated by experts many of whom have expressed little faith in the accuracy of their predictions but who ere virtuslly unanimous in the belief that the deVelopment of these weapons by others is inevitable 6 To deliver on immediately paralyzing blow on aggressor striking against a country armed with atomic weaponss will have to rely upon the highest order Of surprise end striking power He must overwhelm his adversery with such suddenness that rev telietion cannot be undertaken or if attempted will be un successful There will be little solace in ultimate victory if retaliation has brought notional ruin to the victor Thus in such worfere the element of surprise will be an essential the possession of which will be the only assurance of success end whose leek may be catastrophic 7 Offense recognized in the pest es the best means of defense in atomic Werfere will be the only general means of defense Even a nation cepeble of retaining the will on ability to fight victorious war after losses fer greater then_ those of the Pearl Harbor surprise attack can be seriously crippled perhaps defeated by a well planned and executed atomic bomb surprise attack This may hold true no matter how greet the damage inflicted by belated counter-attack 8 Essie to defense against weapons 0f nuclear fission will be first protection against surprise and second the ability to attack with overwhelming force before an enemy can strike significant blow Finn ammo DECLASSIFIED - i authority up EN g IFour--Intelligence 1 Protection against the catastrophic consequenCes of an stemic bomb surprise attack will require an intelligence Service with a far greater effectiveness than any such agency that this country has ever had in peace or war Such an agency charged with the duty of constant world wide scrutiny to determine whether atomic Weapons or other weapons of mass destruction are being manufactured or readied for use must be the first bulwark of our national defense 2 An effective intelligence agency must have theduty of supplying early intelligence of the manufacture by any nation of fissionable material in ear quantity and provid ing pronpt warning should a potential enemy ready atomic weapons for use 3 An effective intelligence service will require a coordina tion cf the effort of existing agencies as well as the employ ment of suitably trained physicists chemists and other scientists Five-- tomic warfare'Policy 1 Traditionally the policy of the United States is one oftki non aggression and as a result in the past we have awaited attack before employing military force ' Because such fore bearance in the future will court catastrophes if not national Vannihilation it is necessary that while adhering in the future to our historic policy of_non aggression we revise past defini tions of what constitutes aggression calling for military action 1 m- oan ha 2 Article 1 Section 8 paragraph ll of the Constitution of the United States gives to the Congress the sole power to make war and neither restricts this power nor offers instruction its use So long as the people of the United States adhere license-era 1 - DECLASSIFIED - tymn LLlolL a i I Authori i to the demdcratic form of government this power must reside in the Congress and Can never be delegated 3 3 Article II Section 2 Paragraph 1 of the Constitution declares that the President shall be'Commander in Chief of the a i VArmy and Navy of the United States Under these ample provisions the United States has success fully defended itself in the past and we can find no reason to believe that the emergence of the atomic boeb requires any alteration of the organic law for our future defense The security demands of the future are those of the past any aggressor must be overcome with superior forcer m 5 Presently the duty of the Commander-invChief before a declaration of'war by the Congress is confined to action only after the loss of American lives or treasure In the future it must be made his duty to defend the country against incipient attack by atomic weapons whenever another nation is readying an atomic attack upon us 6 What constitutes incipient attack it is the responsibility of the Congress to explore and define so that it may draft suit able orders to the Commander in Chief for the prompt and effectch- utilization of our armed forces should we be under the menace of an atomic weapon attack bun - i 7 The processing and stockpiling of fissionable material in 7a certain quantity by a certain nation at a certain time may not constitute an aggressive act incipient attack while the same acts by another nation at another time may upon their-discovery call for swift action in the national defense r 130 _Enclosure I DECLASSIFIED Aiuthority 8 Therefore necessarily the Congress must from time tor time reconsider its definitions of aggressive end incipient attack so that it may alter and change its standing orders to the Commender-in Chief as to the state of feats open which_it becomes his duty to defend the United States against betteck by atomic Weapons 9 It will be the duty end the responsibility-of the Congress to decide whether those definitions and its directions to the acommender-in Chiof be published to the world or be held secret 1 -m 10 Article II Section 2 Paragraph 1 of the Constitution of the United States provides that the President Commander in Chief may require the opinion in writing of the principal officer in each of the executive departments upon any subject Qielating to the duties of their respective offices i ll Whatever may be the legal effect or mandatory force of the foregoing provision it would seem clear that American tradition would require the Commandervin 0hief to receive the advice of Cabinet members before deciding thet dictate -of the Congress reQUiring military action had come into force -- I SiX Consideretion of Targets l The selection of targets for attack by atomic weapons Imust take account of the number of such weapons-available in the predictable future Thus election and priority of targets become of prime importance in the employment of the weapon 1691 10 151 30 Enclosure_ C i DECLASSIFIED i authority 9 2 The correlation of the results of the explosions of atomic - bombs over Japanese cities and against naval vessels at Bikini gives ample evidence that the bomb is pre-eminentlv a weapon for use against human life and activities in large urban and industrial areas as well as seaports 3 Against structures ashore or afloat from a military standpoint the blast effects of the bomb are those of a conven- tional explosive except for their greater magnitude Thus againsi struCtures the bomb has two advantages over other explosives it can accomplish damage over a much greater area and the demands for accuracy in-delivory of a single bomb to produce a given result are far less than for bombs loaded with conventional explosives 4 The atomic bomb will therefore have value in the demolition of structures whenever military judgment dictates that the impor tance of such demolition warrants its use despite the risks and difficulties involved Here the importance of the target combines with the value Of the bomb to emphasize the importance of means of certain_delivery - 5 Dams ship canals naval bases immobilized naval and merchant fleets concentrated in storage areas air fields troops engaged in amphibious landings or concentrated in staging areas may be cited as targets justifying the use of the atomic bomb should special circumstances give them sufficient value 6 It would appear axiomatic that Whenever a target comparable to the foregoing has such high value as to invite atomic bomb attack it will be strongly defended Where dispersion conceal- ment and massive shielding are impracticable then air defenses may be calculated to increase greatly the risk of the delivery of the bomb to such targets by conventional aircraft 132 Enclosure DECLASSIFIED authority ng I 7 In the case of naval vessels the Bikini tests would strongly suggest that ships under way will rarely constitute suitable targets for atomic bomb attack Ships engaged in amphibious operations or carriers or groups of carriers able to launch atomic weapons and ships at anchorage and in harbors will constitute exceptions For the defense in particular cases of Navy Army and Air Force land facilities as well as other installations dams canals atomic bomb dumps industrial plants reliance must be placed in air defense measures and in dispersion concealment massive shielding or underground construction 9 An air defense which would make the delivery cest of bombs prohibitive would certainly be an effective defense as would the protection of a key facility deep underground An intensive and energetic study would reveal the value and practicality bf passive defense for specific targets Sevene Effectiveness of the Bomb against Cities 1 However feasible passive means of defense may prove for small vital installations such protection will be inadequate for a citya Its structures and inhabitants except as interception measures at a distance are effective are fully vulnerable to atomic bomb attack 2 Conventional methods of fire control emergency policing care of the Wounded and the restoration of essential services vould certainly mitigate the results no matter how extensive But the personnel for these services would have to be recruited' from outside the area and where radioactive contamination existed could enter it only with extreme difficulty and after some lapse of time 133 - Enclosure - DECLASSIFIED 3 TEST BAKER gave evidence that the detonation of a bomb in a body of water contiguous to a city would vastly enhance its radiation effects by the creation of a base surge whose mist contaminated with fission products and dispersed by Wind over great areas would have not only an immediately lethal effect but Would establish a long term hazard through the contamination' of structures by the deposition of radioactive particles We can form no adequate mental picture of the multiple disaster which would befall a modern city blasted by one or more atomic bombs and enveloped by radioactive mists Of the survivors 'in contaminated areas some would be doomed to die of radiation sickness in hours some in days and others in years But these areas irregular in size and shape as windand topography might form them would have no visible boundaries No survivor could be certain he was not among the doomed and so added to every terror of the moment thousands would be striken with a fear of death and the uncertainty of the time of its arrival 5 Rescue parties could not enter any part of the city except at the hazard of life until the contaminated areas had been- established and delimited When this had been done relief might be brought to those remaining in contaminated areas but the dead would remain unburied and the wounded uncared for in the areas of eaviest contamination Where certain death would lurk for many days and in which for many years to come continuous thabitation would be unsafe 6 Thousands perhaps millions of refugees would rush from -the city in panic breaking dosh remaining transportation facili ties congesting highways and creating in their flight new hazards to life Among these fugitives for the moment unidenti fiable from the rest would be numbers whose contaminated l34 Enclosure DECLASSIFIED uthority gt i of ng clothing and any goods they carried could establish in others the 'le gl m fear of dangerous radioactivity thus creating a unique logical hazard 9 3 7 It cannot be assumed that in a future war a participant with a range of choice will rely altogether upon a single weapon of mass destructiOn Driven by the necessity of overwhelming his adversary lest he himself be overWhelmed a combatant might well choose to compound the horror of an atomic bomb attack with the simultaneous delivery of pathogenic agents which would insure that frightened fugitives would spread not only their panic but epidemic disease as well Atomic warfare 1 In the foregoing division an attempt has been made to extrapolate from available data a statement of the gross dislocan tions of urban life which may be expected to result from the ex- plosion of atomic bombs against heavily populated areas But largely absent from this statement are speculations as to the tspecific phenomena which such a burst will induce and which must constitute an element of paramount importance in the selection of atomic bomb targets 2 in the body of knowledge of human behavior there are no data directly useful to a discussion of these phenomena as they might occur in a modern Occidental city because there have been no observations of conduct under conditions fully approximating those described above 3 a study of the population behavior in Nagasaki and Hiroshimz' - Manhattan Engineer_District and U S Strategic Bombing Survey Reports offers little help to an understanding of what may be expected in the future in the cases either of air or underwater bursts rior knowledge of the bomb s effects was not possessed 135 Enclosure i uthority EN a ggby inhabitants of the Japanese cities and made no contribution to their behavior patterns Similarly the inhabitants of Japan as a whole even after the fact had little or no knowledge of nuclear phenomena and hence no opportunity to exhibit anticipa tory panic Then too the mental makeup peculiar to the Japanese is probably at greater variance with that of Occidental peoples than the mental makeup of these peoples is one from another This would of course complicate evaluation 4 On each cf the two occasions the atomic weapon was employed in Japan a single bomb only was burst in air over a single city on a sicgle mission providing no picture of the national situae tion which might have resulted had tens or hundreds of bombs been discharged within a brief period of time over several cities 5 Moreover there are lacking from an air burst many of the important stimuli which would be present after an under- water explosion 6 In the face of these negative findings and of the bomb s demonstrated power to deliver death to tens of thousands of primary military concern will be the bomb s potentiality to break the will of nations and of peoples by the stimulation of man s primordial fears those of the unknown the invisible the mysterious We may deduce from a wide variety of established facts that the effective exploitation of the bomb s implications will take precedence over the application of its destructive and lethal effects in deciding the issue of war 7 A thorough Study of the many-faceted problem will doubtless reveal a wide variation in the mili- tary value of cities as targets TOP MT JCS 1591710 136 Enclosure - DECLASSIFIED 8 There are countries where because communication facilities are so limited large areas might be depopulated with little or no effect upon the morale of the country at large There are cities of especial sentimental significance whose loss to a country might have a more profound effect upon the national will than the destruction of areas more important intrinsically 9 There are cities symbolic of national greatness beyond their conventional military importance There are capital cities vital to the national unity necessary to the prosecution of war the loss of other capitals might scarcely distrub their nation's military tempo 10 Of as wide variation and of equal importance it will probably be found are national temperaments ways of life and_ ylevels of education Paradoxically it would seem that within some limits the greater the knowledge of nuclear fission phenomena the greater the fear it engenders Dwellers of a city who are aware of the nature of the Calamities being afflicted' upon their fellow of another city will identify theme Selves with these calamities and may the more easily translate' early fear into ultimate alarm and panic Less likely are persons largely ignorant of the manifold deadliness of an atomic bomb to make these adjustments 11 With the question of a given group s reaction to the dis charge of an atomic bomb as compared to the reactions of other groups is raised the consideration of propaganda as a means of -enhancing the bomb's military utility Coupled with this are considerations of the communication facilities of_a giVen country and of the extent of the free exchange of information 12 Even a cursory examination of the characteristics of the American people and of the cultural and material fabric of their national life invites the conclusion that this nation is much mor vulnerable to the effects of the bomb than certain other nations A study of the factors involved should not only asaist us in determining the vulnerabilities of other nations but also should lead to the development of measures to lessen the effects of these phenomena should we be attacked Nine Continuous Review of Targets l The selection of atomic bomb targets will be seen to involve problems far more numerous and complex than those involved in the selection of targets for conventional weapons To be fully effective the survey of potential targets will have to be con tinuous so that the relative importance as well as the accessi- bility of a given target may be knewn at all times 2 Exactly as the atomic weapon and weaponwcarrier must be regarded as an integrated weapon and the development of each coordinated with the development of the other so the considera tion of suitable targets is inseparable from consideration of the combined potential of weapon andeeapon-carrier to give a DECLASSIFIED desired result Ten- Concluding Observations l The effort to appreciate the implications of atomic energy is taxing the apperceptive powers of the most unfettered minds in every field of thought Its use as an implement of war poses a wider variety of new and complex problems than have ever before confronted military planners Not merely the overcoming of the inertia of conservatism is here required but a revolutionary change in military mental attitudes 2 It_is not always the nation first introducing a new weapon which develops its highest utility England invented the tank but Germany developed the tactics which made it a major weapon Germany first employed lethal gas in battle but her failure to $11013 DECLASSIFIED Authori i develop quickly a suitable technique of use may have cost her victory in the first World war The possible penalty of a failure to retain dominance in the development of the atomic bomb and of the strategy and tactics of its use is so great that it must 7 serve as a constant incentive to the best thought and effort of our military planners 3 In conclusion the Board reverts to the ATOMIC ENERGY ACT and its basic provisions In our opinion these basic provisions however justified at the moment of the ACT's passage lshould be reviewed from time to time in the light of changing events 4 The Board offers no criticism of the ATOMIC ENERGY In a friendly and cooperative spirit and with long term effectiveness of the national defense in mind the Board recommends a reconsideration by proper authorities of the quash tions Whether the Services should have representation on the ATOMIC ENERGY COMMISSION own have title to and be charged with the control of atomic weapons after fabrication participate in the work of the design and testing of atomic weapons and control all information relating entirely to the military utilization of the weapons as distinguished from design and development information A DECLASSIFIED ENCLOSURE DRAFE washington D C Prepared by the Joint Chiefs of Staff Evaluation Board for Release to the Press The final report of the Joint Chiefs of Staff Evaluation Board for the Bikini Atomic Bomb tests was released for publi cation today The Board which was appointed late in the fall of 1945 was composed of three civilians and four Service 'members It was headed by Dr Karl T Compton president of the Massachusetts Institute of Technology The other members were Mr Bradley Dewey president of the American Chemical Society former Rubber Director and president of the Dewey and Almy Chemical Company Cambridge Massachusetts Mr Thomas F Farrell formerly Major General Deputy Commander of the Manhattan District and Chief Engineer of New York State presently chairman New York Housing Authority and the following Service members Lieutenant General L H Brereton Vice Admiral John H Hoover Rear Admiral Ralph A Ofstie Lieutenant General_a C Wedemeyer General Joseph W Stilwell an original member of the Board died before the conclusion of its duties His place was taken by General wedemeyer A note accompanying the public version of the report explains that certain of its sections have been deleted for reasons of national security including that information which has been deleted in accordance_with provisions of the Atomic Energy Act Cf chief importance and interest the Board proposes that Congress accept leadership in bringing national thinking up to - date and in line with the necessities of the age of atomic warfare '140 Finn Genre It points out that where in the past the United States has been able to follow a tradition of never striking until it is struck - such a policy in the future may be catastrophic An enemy armed with atomic weapons might do irreparable damage before we could strike back Therefore the Board proposes that Congress define and from time to time redefine what constitutes an aggressive act and that it direct the President as Commander in Chief to launch an attack against any nation when in his opinion and in that of his cabinet that nation is preparing an atomic attack upon the United States i -mwm Other points made by the report are The flat declaration that passive defense measures such as bomb-proofing and underground construction are impracticable for the defense of cities The statement that the emergence of the atomic weapon gig has not eliminated the need for land sea and air forces The Bikini tests did not indicate the need for radical 3 changes in naval ship designr a g The necessity for constant and unremitting research and 4 auew m' development in nuclear science and atomic weapon production so that the united States may retain its leadership the loss of which might result in national disaSter - The necessity for further atomic bomb tests as part of a research and development program The report points out that the bomb can be a weapon of warfare and that there is a need for the education of both the armed services and the public to lessen its effects should it be used against this country The Board strongly recommends that chief reliance against the bomb be placed in the prevention or frustration of attacks against us and upon immediate retaliatory measures -1 1h points out that where in the past the United States has been able to follow a tradition of never striking until it is struck ' such a policy in the future may be catastrophic An enemy armed with atomic weapons might do irreparable damage before we could strike back Therefore the Board proposes that Congress define and from time to time redefine what constitutes an aggressive act and that it direct the President as Commander in Chief to launch an attack against any nation when in-his opinion and in that of his cabinet that nation is preparing an 3 atomic attack upon the United States _llm i Other points made by the report are The flat declaratiOn that passive defense measures such as bomb-proofing and underground construction are impracticable for the defense of cities The statement that the emergence of the atomic weapon has not eliminated the need for land sea and air forces The Bikini tests did not indicate the need for radical changes in naval ship design The necessity for constant and unremitting research and a DECLASSIFIED e 5 development in nuclear science and atomic weapon production so that the united States may retain its leadership the loss of which might result in national disaSter The necesgity for further atomic bomb tests as part of a research and development program The report points out that the bomb can be a weapon of warfare and that there is a need for the education of both the armed services and the public to lessen its effects should it be used against this country The Board strongly recommends that chief reliance against the bomb be placed in the prevention or frustration of attacks against us and upon immediate retaliatory measures 141 Enclosure The Board_urges the establishment of an intelligence service of far greater effectiveness than this country has had in peace or war The Board also recommends that Congress review in the 1 i light of new considerations the Atomic Energy Act M s The Board is emphatic in its assertion that if used in suitable numbers atomic weapons can destroy nations and that the one and only safeguard mankind can have against the fear of the destruction of civilization is the outlawing of war in all forms