PEARL HARBOR ATTACK 73 PART III RESPONSIBILITIES IN HAWAII 74 PEARL HARBOR ATTACK [Blank] PEARL HARBOR ATTACK 75 PART III. RESPONSIBILITIES IN HAWAII CONSCIOUSNESS OF DANGER FROM AIR ATTACK ADMIRAL KIMMEL'S AWARENESS OF DANGER FROM AIR ATTACK The Japanese raiding force approached the island of Oahu with virtually no danger of detection and executed its treacherous attack at a time when only a minimum state of readiness prevailed to meet it. [1] One of the causes of the disaster in consequence must lie in the failure to employ facilities available to detect the attacking force in sufficient time to effect a state of readiness best designed to repel or minimize the attack. That the attack on Pearl Harbor surprised the defending Army and Navy establishments is indisputable. The question therefore becomes, as previously indicated: Under all of the circumstances should the responsible commanders at Hawaii have been surprised or, more particularly, were they justified in failing to employ adequately the defensive facilities available to them on the morning of December 7, 1941? [2] The estimate of both Admirals Richardson [3] and Kimmel [4] in a letter which they jointly prepared and dispatched to the Chief of Naval Operations on January 25, 1941, pointed out that if Japan entered the war or committed an overt act against the United States our position would be primarily defensive in the Pacific. [5] There were outlined in the letter certain assumptions upon which the action of the Pacific Fleet would be predicated, including: "(a) United States is at war with Germany and Italy; (b) war with Japan imminent; (c) Japan may attack without warning, and these attacks may take any form even to attacks by Japanese ships flying German or Italian flags or by submarines, under a doubtful presumption that they may be considered German or Italian; and (d) Japanese attacks may be expected against shipping, outlying positions, or naval units. Surprise raids on Pearl Harbor, or attempts to block the channel are possible. " It was pointed out that the tasks to be undertaken by the fleet with respect to these assumptions included the taking of full security [1] See section "State of Readiness," Part II, supra. [2] The Army Pearl Harbor Board said: "Therefore, the situation on December 7 can be summed up as follows: No distant reconnaissance was being conducted by the Navy; the usual four or five PBY's were out; the antiaircraft artillery was not out on its usual Sunday maneuvers with the Fleet air arm, the naval carriers with their planes were at a distance from Oahu on that Sunday; the aircraft were on the ground, were parked, both Army and Navy, closely adjacent to one another; the Fleet was in the harbor with the exception of Task Forces 9 and 12, which included some cruisers, destroyers, and the two carriers Lexington and Enterprise. Ammunition for the Army was, with the exception of that near the fixed antiaircraft guns, in ordnance storehouses, and the two combat divisions as well as the antiaircraft artillery were in their permanent quarters and not in battle positions. Everything was concentrated in close confines by reason of anti-sabotage Alert No. 1. This made of them easy targets for an air attack. *In short everything that was done made the situation perfect for an air attack and the Japanese took full advantage of it.*" See Report of Army Pearl Harbor Board, Committee Exhibit No. 157 [3] Admiral James O. Richardson, who preceded Admiral Kimmel as commander in chief of the Pacific. [4] Admiral Husband E. Kimmel assumed command of the United States Pacific Fleet on February 1, 1941 and served in that capacity until December 17, 1941. The evidence clearly indicates that while Admiral Kimmel was promoted over several other officers with more seniority, his selection was made because he was regarded as preeminently qualified for the position of commander in chief. [5] See Navy Court of Inquiry exhibit No. 70. 76 PEARL HARBOR ATTACK measures for the protection of the fleet in port and at sea. Thereafter there were set forth observations concerning the existing deficiencies in the defenses of Oahu. Under date of January 24, 1941, the Secretary of Navy addressed a communication to the Secretary of War, with copies designated for the commander in chief of the Pacific Fleet and the commandant of the Fourteenth Naval District, observing among other things: [6] "The security of the U. S. Pacific Fleet while in Pearl Harbor, and of the Pearl Harbor Naval Base itself, has been under renewed study by the Navy Department and forces afloat for the past several weeks. This reexamination has been, in part, prompted by the increased gravity of the situation with respect to Japan and by reports from abroad of successful bombing and torpedo plane attacks on ships while in bases. *If war eventuates with Japan, it is believed easily possible that hostilities would be initiated by a surprise attack upon the Fleet or the Naval Base at Pearl Harbor.* "In my opinion, the inherent possibilities of a major disaster to the Fleet or naval base warrant taking every step, as rapidly as can be done, that will increase the joint readiness of the Army and Navy to withstand a raid of the character mentioned above. "The dangers envisaged in their order of importance and probability are considered to be: "(1) Air bombing attack. "(2) Air torpedo plane attack. "(3) Sabotage. "(4) Submarine attack. "(5) Mining. "(6) Bombardment by gun fire. "Defense against all but the first two of these dangers appears to have been provided for satisfactorily. The following paragraphs are devoted principally to a discussion of the problems encompassed in (1) and (2) above, the solution of which I consider to be of primary importance. "Both types of air attack are possible. They may be carried out successively, simultaneously, or in combination with any of the other operations enumerated. The maximum probable enemy effort may be put at twelve aircraft squadrons and the minimum at two. Attacks would be launched from a striking force of carriers and their supporting vessels. "The counter measures to be considered are: "(a) Location and engagement of enemy carriers and supporting vessels before air attack can be launched; "(b) Location and engagement of enemy aircraft before they reach their objectives; "(c) Repulse of enemy aircraft by antiaircraft fire "(d) Concealment of vital installations by artificial smoke; "(e) Protection of vital installations by balloon barrages. "The operations set forth in (a) are largely functions of the Fleet but, quit possibly, might not be carried out in case of an air attack initiated without warning prior to a declaration of war Pursuit aircraft in large numbers and an effective warning net are required for the operations in (b). It is understood that only thirty-six Army pursuit aircraft are at present in Oahu, and that, while the organization and equipping of an Anti-Air Information Service supported by modern fire control equipment is in progress, the present system relies wholly on visual observation and sound locators which are only effective up to four miles. * * *" The foregoing communication was seen by Admiral Kimmel shortly after he assumed command. [7] The Secretary of War on February 7, 1941, replied to the letter of the Secretary of Navy in the following terms: [8] "1. In replying to your letter of January 24, regarding the possibility of surprise attacks upon the Fleet or the Naval Base at Pearl Harbor, I wish to express complete concurrence as to the importance of this matter and the urgency of our making every possible preparation to meet such a hostile effort. The Hawaiian [6] Committee Exhibit No. 10. [7] Admiral Kimmel testified: "* * * I saw the letter of the Secretary of the Navy to the Secretary of War dated January 24, 1941, early in February 1941." Navy Court of Inquiry Record, p. 286. [8] Navy Court of Inquiry exhibit No. 24. PEARL HARBOR ATTACK 77 Department is the best equipped of all our overseas departments, and continues to old a high priority for the completion of its projected defenses because of the importance of giving full protection to the Fleet. "2. The Hawaiian Project provides for one hundred and forty-eight pursuit planes. There are now in Hawaii thirty-six pursuit planes, nineteen of these are P-36's and seventeen are of somewhat less efficiency. I am arranging to have thirty-one P-36 pursuit planes assembled at San Diego for shipment to Hawaii within the next ten days, as agreed to with the Navy Department. This will bring the Army pursuit group in Hawaii up to fifty of the P-36 type and seventeen of a somewhat less efficient type. In addition, fifty of the new P-40-B pursuit planes, with their guns, leakproof tanks and modern armor will be assembled at: San Diego about March 15 for shipment by carrier to Hawaii. "3. There are at present in the Hawaiian Islands eighty-two 3-inch AA guns, twenty 37 mm AA guns (en route) and one hundred and nine caliber .50 AA machine gun}. The total project calls for ninety-eight 3-inch guns, one hundred and twenty 37 mm AA guns, and three hundred and eight caliber .50 AA machine guns. "4. With reference to the Aircraft Warning Service, the equipment therefor has been ordered and will be delivered in Hawaii in June. All arrangements for installation will have been made by the time the equipment is delivered. Inquiry develops the information that delivery of the necessary equipment cannot be made at an earlier date. "5. The Commanding General, Hawaiian Department, is being directed to give immediate consideration to the question of the employment of balloon barrages and the use of smoke in protecting the Fleet and base facilities. Barrage balloons are not available at the present time for installation, and cannot be made available prior to the summer of 1941. At present there are three on hand and eighty-four being manufactured forty for delivery by June 30, 1941, and the remainder by September. The Budget now has under consideration funds for two thousand nine hundred and fifty balloons. The value of smoke for screening vital areas in Oahu is a controversial subject. Qualified opinion is that atmospheric and geographic conditions in Oahu render the employment of smoke impracticable or large-scale screening operations. However, the Commanding General will look into this matter again. "6. With reference to your other proposals for joint defense, I am forwarding a copy of your letter and this reply to the Commanding General, Hawaiian Department, and am directing him to cooperate with the local naval authorities in making those measures effective." In a letter to the Chief of Naval Operations dated January 27, 1941, [9] Admiral Kimmel stated he thought the supply of an adequate number of Army planes and guns for the defense of Pearl Harbor should be given the highest priority. It should be noted at this point in considering the letter of the Secretary of Navy dated January 24, 1941, that the following dispatch dated February 1, 1941, was sent the commander in chief of the Pacific Fleet from the Chief of Naval Operations concerning the subject "Rumored Japanese attack on Pearl Harbor": [10] "1. The following is forwarded for your information. Under date of 27 January the American Ambassador at Tokyo telegraphed the State Department to the following effect: " "The Peruvian Minister has informed a member of my staff that he has heard from many sources, including a Japanese source, that in the event of trouble breaking out between the United States and Japan, the Japanese intend to make a surprise attack against Pearl Harbor with all of their strength and employing all of their equipment. The Peruvian Minister considered the rumors fantastic. Nevertheless he considered them of sufficient importance to convey this information to a member of my staff." "2. The Division of Naval Intelligence places no credence in these rumors. furthermore, based on known data regarding the present disposition and employment of Japanese Naval and Army forces, no move against Pearl Harbor appears imminent or planned for in the foreseeable future. [9] Committee exhibit No. 106. [10] This dispatch is indicated to have been dictated by Lt. Comdr. (now Captain) A. H. McCollum on January 31, 1941. See committee exhibit No. 15. 78 PEARL HARBOR ATTACK The estimate made concerning the information supplied by the Peruvian Minister with respect to a rumored Japanese surprise attack on Pearl Harbor and a copy of the Secretary of the Navy's letter of January 24 were received by Admiral Kimmel at approximately the same time and are in apparent conflict. However, the dispatch of February 1 was an estimate of the rumor concerning the Japanese plan to make a surprise attack on Pearl Harbor based on the then present disposition and employment of Japanese forces, whereas the Secretary's letter relates to the dangers of the Pearl Harbor situation in contemplation of future conflict with Japan. The communications apparently were so interpreted by Admiral Kimmel for in a letter dated February 18, 1941, to the Chief of Naval Operations he said: [11] "I feel that a surprise attack (submarine, air, or combined) on Pearl Harbor is a possibility. We are taking immediate practical steps to minimize the damage inflicted and to ensure that the attacking force will pay." In a letter of February 15, 1941 [12] the Chief of Naval Operations wrote Admiral Kimmel concerning antitorpedo baffles for protection against air-torpedo attack on Pearl Harbor. He stated that the congestion in the harbor and the necessity for maneuverability limited the practicability of the then present type of baffles. Further, the letter indicated that the shallow depth of water in Pearl Harbor limited the need for torpedo nets; that a minimum depth of water of 75 feet might be assumed necessary to drop torpedoes successfully from planes and that the desirable height for dropping is 60 feet or less. A similar communication was sent Admiral Bloch, the commandant of the Fourteenth Naval District, among others, requesting his recommendations and comments concerning the matter. [13] In a letter of March 20, [14] Admiral Bloch replied, stating that the depth of water at Pearl Harbor was 45 feet and for this reason among others he did not recommend antitorpedo baffles. Admiral Kimmel was in agreement with this recommendation until such time as a light efficient net was developed. [15] However, in June of 1941, the Chief of Naval Operations directed a communication to the commandants of naval districts as follows: [16] "1. * * * Commandants were requested to consider the employment of, and to make recommendations concerning, antitorpedo baffles especially for the protection of large and valuable units of the fleet in their respective harbors and especially at the major fleet bases. In paragraph 3 were itemized certain limitations to consider in the use of A/T baffles among which the following was stated: " "A minimum depth of water of 75 feet may be assumed necessary to successfully drop torpedoes from planes. About two hundred yards of torpedo run is necessary before the exploding device is armed, but this may be altered." "2. Recent developments have shown that United States and British torpedoes may be dropped from planes at heights of as much as three hundred feet, and in some cases make initial dives of considerably less than 75 feet, and make excellent runs. Hence, it may be stated that it cannot be assumed that any capital ship or other valuable vessel is safe when at anchor from this type of attack if surrounded by water at a sufficient run to arm the torpedo. "3. While no minimum depth of water in which naval vessels may be anchored can arbitrarily be assumed as providing safety from torpedo- plane attack, it may [11] Committee exhibit No. 106. [12] Id., No. 116. [13] Letter from Chief of Naval Operations dated February 17, 1941. Committee exhibit No. 116. [14] See Committee exhibit No. 116. [15] Letter to the Chief of Naval Operations dated March 12,1941, Committee exhibit No. 116 [16] Letter dated June 13, 1941, from Chief of Naval Operations to commandants of all naval districts. Committee exhibit No. 116. This communication made reference to the observations set forth in the letter of February 17,1941 (committee exhibit No. 116), pointing out certain limitations with respect to air torpedo attack. Note 13, supra. PEARL HARBOR ATTACK 79 be assumed that depth of water will be one of the factors considered by any attacking force, and an attack launched in relatively deep water (10 fathoms [16a] or more) is much more likely. "4. As a matter of information the torpedoes launched by the British at Taranto were, in general, in thirteen to fifteen fathoms of water, although several torpedoes may have been launched in eleven or twelve fathoms. [17]" The foregoing communication clearly indicated that preconceived views concerning the invulnerability of Pearl Harbor to air-torpedo attack were in error. Admiral Kimmel himself stated that during his visit to Washington in June of 1941 he told the President and Admiral Stark of certain dangers to the feet at Pearl Harbor including air attack, blocking of the harbor, and similar matters. [18] GENERAL SHORT'S AWARENESS OF DANGER FROM AIR ATTACK On February 7, 1941, General Short [19] assumed command of the Hawaiian Department of the Army. Upon his arrival he had the benefit of conversations with General Herron, [20] his predecessor, with respect to problems prevailing in the Department. Significantly General Herron had been directed by the War Department on June 17, 1940, to institute an alert against a possible trans-Pacific raid. [21] This alert was an all- out endeavor with full equipment and ammunition and lasted 6 weeks. It was suspended after the 6-week period and thereafter resumed for some time. Planes had been dispersed and gun crews alerted with the ammunition available. The Commanding General lead the benefit of all the plans and operations incident to the so-called "Herron alert" as a guide in estimating the steps to be taken on the occasion of a threat of enemy attack. General Short saw both the letter from the Secretary of Navy dated January 24 and the reply of the Secretary of War dated February 7, set forth in the preceding section, concerning the danger of attack from the air. [22] Under date of February 7, 1941, General Marshall directed a letter to General Short relating in utmost clarity the problems and responsibility of General Short in his new command. [23] This letter, which referred to a conversation with Admiral Stark, pointed out that there was need for additional planes and antiaircraft guns; that the fullest protection for the Pacific Fleet was *the* rather than *a* major consideration of the Army; that the risk of sabotage and the risk involved in a surprise raid by air and by submarine constituted the real perils of the situation; and, again, that they were keeping clearly in mind that the first concern is to protect the feet. On February 19, 1941, General Short wrote General Marshall [24] pointing out, among other things, the great importance of (1) cooperation with the Navy; (2) dispersion and protection of aircraft and of the repair, maintenance, and servicing of aircraft; (3) improvement of the [16a] A fathom is 6 feet. [17] The evidence reflects repeated efforts by the Chief of Naval Operations to secure from the Bureau of Ordnance more efficient light- weight baffles. See committee exhibit No. 116. [18] Navy Court of Inquiry record, p. 367. [19] Lt. Gen Walter C. Short served as commanding general of the Hawaiian Department from February 7, 1941, to December 17, 1941. [20] Maj. Gen. Charles B. Herron. [21] See Army Pearl Harbor Board record, pp. 213-215. [22] Navy Court of Inquiry record, p. 237. [23] Committee exhibit No. 53, pp. 1-3. [24] Id., at pp. 4-9.