Chapter 7: 7. Japanese Action Appears Imminent U. S. War Plans—To Raid and Destroy Japanese Bases in Far East in Support of Associated Powers

Military forces regularly make plans for the defense of their country under various contingencies. However, by 1941 the U.S. military had developed war plans that went far beyond trying to defend the nation against foreign aggressors. Our Army, Navy, and Air forces were operating under a war plan based on a secret agreement reached during the American-British Conversations (ABC) held in Washington early in 1941. This agreement had been “approved by the Joint Board, the Secretaries of War and Navy, and by the president.”^[1] Chief of Navy War Plans Richmond Kelly Tuner termed it

a world-wide agreement, covering all areas, land, sea, and air, of the entire world in which it was conceived that the British Commonwealth and the United States might be jointly engaged in action against any enemy.

In line with the so-called ABC-I agreement,

a joint Army-Navy plan was prepared after a great many talks with the Army . . . [and] was approved by the Secretary of the Navy on May 28, 1941, and by the Secretary of War on June 2, 1941. It bore the short title “Rainbow No. 5.’” On the basis of the Joint Army and Navy Basic War Plan the Navy Department promulgated the Navy Basic War Plan on May 26, 1941. This plan bore the short title “WPL-46”. . . . The War Plan of the Pacific Fleet was distributed on July 25, 1941.^[2]

It had been customary to name an operating plan by the color code name assigned to the potential enemy concerned. Japan had traditionally been designated “orange,” other countries “blue,” “red,” and so on. However, as ABC-I contemplated action against several enemy nations, it wasn’t feasible to designate its operating plan by a single color. Hence the code name “Rainbow.”^[3] Several Rainbow operating plans, each numbered consecutively and each providing for a different contingency, were developed to implement the ABC-I agreement. The first four were eventually set aside. It was Rainbow No. 5 that the Navy issued in May 1941 and sent out to the fleet commanders, including Kimmel in Hawaii, for distribution in July 1941 to the various task forces.

The ABC-I agreement called on the United States to employ its Pacific Fleet “offensively in the manner best calculated to weaken Japanese economic power.”^[4] To accomplish this, our naval forces were to

Support the forces of the Associated Powers in the Far East Area by diverting enemy strength away from the Malay Barrier through the denial and capture of positions in the Marshalls, and through raids on enemy sea communications and positions.^[5]

U.S. Pacific Fleet Operating Plan Rainbow No. 5 stipulated that “In the event of an overt act of war by a foreign power against the United States prior to the existence of a state of war,” the senior commander, then Admiral Kimmel at Pearl Harbor, was “to take such action in the defense of his command and the national interests as the situation may require, and report the action taken to superior authority at once.”^[6] The Plan called on the fleet to reconnoiter, sweep, patrol, and protect. However, the primary objective prescribed for the Pacific Fleet under Rainbow No. 5 was to prepare to raid, capture, and destroy the bases in the Japanese-controlled Marshall and Caroline islands. The assignments of each task force were set forth in detail in the plan.^[7]

Stark and Marshall Again Ask for Time to Build U.S. Defenses

Before Marshall left for maneuvers on November 26, he and Chief of Naval Operations Stark prepared a joint memorandum to the president on the “Far Eastern Situation.”^[8] Dated November 27, their memorandum expressed concern that they might not have enough time to build up their forces before a Japanese strike. They reminded FDR that if the current negotiations with the Japanese ambassadors failed, “Japan may attack: the Burma Road; Thailand; Malaya; the Netherlands East Indies; the Philippines; the Russian Maritime Provinces.” Navy and Army reinforcements were being rushed to the Philippines. From the U.S. viewpoint, Marshall and Stark wrote, the “most essential thing now . . . is to gain time.” They were especially concerned for the safety of an Army convoy then near Guam and a Marine Corps’ convoy just leaving Shanghai. They cautioned, however, that “so long as consistent with national policy,” we should avoid precipitating any conflict.

Marshall and Stark also wrote it had been agreed, after consultation with the British and Dutch military authorities in the Far East,

that joint military counteraction against Japan should be undertaken only in case Japan attacks or directly threatens the territory or mandated territory of the United States, the British Commonwealth, or the Netherlands East Indies, or should the Japanese move forces into Thailand west of 1000 East or south of 100 North, Portuguese Timor, New Caledonia, or the Loyalty Islands.

Japan should be warned that “advance beyond the lines indicated may lead to war.” However, “prior to such warning, no joint military opposition [should] be undertaken.” Moreover, Marshall and Stark said, agreement with the British and Dutch should be sought on issuing such a warning.

The first thing in the morning of November 27, Secretary of War Stimson phoned Secretary of State Hull to find out “what his finale had been with the Japanese.” Had Hull handed them the three-month modus vivendi proposal, which had been approved a couple of days before? Or had he put an end to the negotiations, as he had said he might. Hull told Stimson he had broken the whole matter off: “I have washed my hands of it and it is now in the hands of you and Knox—the Army and Navy.” Later FDR gave Stimson a slightly different view. However, he too said the negotiations had “ended up, but they ended up with a magnificent statement prepared by Hull.”^[9]

FDR Messages British Intelligence Agent Stephenson, “Japanese Negotiations Off . . .”

As soon as the president learned that the negotiations with the Japanese had been broken off, he sent his oldest son, James, as his emissary to British intelligence agent Sir William Stephenson. On November 26, James Roosevelt travelled to New York and informed Stephenson, of the tenuous Japanese situation. Stephenson cabled Churchill on November 27:

JAPANESE NEGOTIATIONS OFF. SERVICES EX- PECT ACTION WITHIN TWO WEEKS.^[10]

Washington Warns Philippines of Possible Japanese Attack

On November 27, General Douglas MacArthur and Admiral Hart, Commander-in-Chief of the Asiatic Fleet, met in the office of High Commissioner Francis B. Sayre to discuss the seriousness of FDR’s November 26 warning cable to Sayre. Pacing back and forth and smoking a big black cigar, General MacArthur assured Hart and Sayre that “the existing alignment and movement of Japanese troops convinced him that “there would be no Japanese attack before the spring.”^[11] Admiral Hart disagreed.

Reports were arriving in Washington regularly of the daily reconnaissance overflights conducted from the Philippines to keep track of the large Japanese convoy heading south from Shanghai. Thus news of the Japanese expeditionary force came in on November 27, apparently heading toward the Philippines, Burma, the Burma Road, or the Dutch East Indies. And it was expected that a concentration of Japanese troops would move over into Thailand and take a position there, from which an attack could be launched on Singapore. Stimson suggested to FDR that MacArthur in the Philippines be sent “a final alert.” We had already sent MacArthur a “quasi alert,” but Stimson thought he should be given a further warning against a possible Japanese attack. The president agreed.^[12]

Arrangements were being made to fly B-l7s out to the Philippines to reinforce our defenses there. Army Air Force Commanding General Arnold called on Stimson on November 27 to present the orders for two of our biggest planes to move out of San Francisco en route to Manila and fly over—while photographing—the Japanese mandated islands, where the Japanese were known to be building military bases. These big planes would be able to fly high enough to be out of reach of the Japanese pursuit planes.^[13]

Secretary of Navy Knox and Stark called on Stimson on November 27 to talk about the warning to be sent MacArthur in the Philippines. General Leonard T. Gerow, Army chief of war plans, was also present. A message to MacArthur calling for action, such as Stimson was considering, would normally have been prepared and sent by the Army chief of staff. It was most unusual to send a message to a field commander signed “Marshall,” which had not actually been dispatched by him.^[14] Marshall was familiar with U.S. military outposts in a way that the secretary of war was not. Also, the responsibility for strategic command decisions flowed from the commander-in-chief (the president) to the chief of staff; the chief of staff reported to the president. The secretary of war’s duties lay outside this line of command; they related primarily to personnel requirements and matters of supply. However, Marshall was out of the city. So Stimson, Stark, and Gerow went ahead on their own.

Stark and Gerow, quite naturally, were pressing for more time for the military buildup before a Japanese strike. Stimson said he would be “glad to have time” but not at the expense of backing down. He “didn’t want it [time] at any cost of humility on the part of the United States . . . which would show a weakness on our part.” Before they finished drafting their message to MacArthur, they called Hull to learn the latest on the situation with the Japanese.^[15] They sent the message over Marshall’s signature. Although directed primarily to MacArthur in the Philippines, the Stimson-Stark-Gerow cable, with slight changes and also signed “Marshall,” went to the Army’s commanding generals in Hawaii and the Panama Canal Zone.

In Response to Army’s Warning, General Short (Hawaii) Reports Sabotage Alert

The version of the Stimson-Stark-Gerow cable sent to Short in Hawaii advised that “Negotiations with Japan appear to be terminated to all practical purposes. . . . Japanese future action unpredictable but hostile action possible at any moment. If hostilities cannot, repeat cannot, be avoided the United States desires that Japan commit the first overt act.” However, this should “not be construed as restricting you to a course of action that might jeopardize your defense.” Reconnaissance and other measures necessary should be carried out with caution so as “not, repeat not, to alarm civil population or disclose intent.” Short was asked to “Report measures taken.”^[16]

The Army was responsible for protecting the fleet when it was in port. On receipt of this message (No. 472) on November 27, Short called a meeting of his staff. He had been instructed “to undertake such reconnaissance . . . as you deem necessary.” At the same time he was “not . . . to alarm civil population.”

Adequate reconnaissance to guard Hawaii against surprise attack would have required 360-degree surveillance, 24 hours a day. According to Admiral P.N.L. Bellinger, commander of the Hawaiian Naval Base Air Force, and Commander Logan C. Ramsey, his operations officer at the time of the attack, such wide-ranging reconnaissance was not realistic, given the planes and resources then available there. Most of their B-17s had been sent to the Philippines. Only eight that could have been used for long-range reconnaissance were available at the time of the attack, and not all of those were in flying condition. Planes cannot fly continuously; they wear out and need servicing from time to time. Crews need rest too; it is estimated that crews flying long-range reconnaissance shouldn’t be asked to operate more often than one in three days.^[17] Thus long-range reconnaissance could not have been maintained indefinitely in Hawaii—its success depended on timely warning of any potential threat.

Marshall was familiar with the shortage of planes in Hawaii. But Stimson, who had drafted the November 27 warning message, was not. The Hawaiian command had three different alerts from which to choose. Marshall was also familiar with the Army’s system of alerts; again, Stimson was not.

In view of the Army’s responsibility and the instruction not to alarm the public, a large percentage of whom were ethnic Japanese, Short decided to go on a sabotage alert, clustering the planes and storing the ammunition underground. This was the most effective way to guard against subversive activities in an area surrounded by potential enemies. On the assumption that the cable had come from Marshall, Short wired Washington that afternoon that he had “alerted to prevent sabotage” and had established “liaison with Navy.”^[18]

Short’s response was received in Washington on November 28, at 5:57 am.^[19] Under Army rules and regulations then in force, if a junior officer, on receiving an order, reports measures taken and his superior officer does not countermand them, the responsibility for any error or mistake in judgment lies with the superior officer. Short was the junior officer; Marshall his superior. As instructed, Short reported the measures taken. If his action was not considered appropriate, normal Army procedure would have called for Marshall to order him to change his alert. No such order was given. The planes and ammunition remained as they were until the Japanese attack ten days later.

Admiral Stark’s “War Warning” to Hart (Philippines) and Kimmel (Hawaii)

Also on November 27, CNO Stark sent his fleet commanders a “war warning,” reporting on the status of U.S.-Japan relations. Admiral Hart, commander-in-chief of the Asiatic Fleet in the Philippines, was the first addressee; Admiral Kimmel, commander-in-chief of the Pacific Fleet at Pearl Harbor, was second. Information copies went to Admiral King, commander-in-chief of the Atlantic Fleet and to the special naval observer in London.

“Negotiations with Japan looking towards stabilization of conditions in the Pacific have ceased,” Stark told his commanders in this “war warning.” An “aggressive move” on the part of the Japanese was “expected within the next few days . . . an amphibious expedition against either the Philippines Thai or Kra peninsula or possibly Borneo. . . . Continental districts Guam Samoa directed take appropriate measures against sabotage.” The commanders should prepare to put WPL 46 (War Plan 46, Rainbow No. 5) into operation.^[20]

The morning after this dispatch was received, Kimmel discussed its significance with the senior Army and Navy officers in Hawaii—Short; Admiral Bloch, commandant of the 14th Naval District who was in charge of naval shore establishments in Hawaii; the flag officers of the fleet then in port, as well as the members of Kimmel’s staff. After considerable study they “interpreted the warning to mean that war was imminent, and that readiness to undertake active operations was expected.” To Kimmel being ready “to undertake active operations” meant “carrying out the tasks assigned in WPL-46.” And that meant preparing for offensive action in line with War Plan 46, then in operation, against the Japanese in the Marshall and Caroline Islands in the southwestern Pacific.

This November 27 cable did not suggest the possibility of “a surprise aggressive move ‘in any direction” as had the dispatch sent three days earlier.^[21] Thus the specific mention of “the Philippines, Thai or Kra peninsula or possibly Borneo” as the intended destination of the Japanese expedition served only to reconfirm the conclusion they had drawn from the earlier message, namely that the Japanese were most likely to strike in the southwest Pacific or southeast Asia. Other Washington directives served to strengthen this impression. For instance, the Navy had recently been ordered to send “a squadron of submarines . . . to the Philippines, leaving only 5 in Pearl Harbor.” And on November 28, Kimmel was advised that the Marines on the islands of Midway and Wake, in the middle of the Pacific, were to be replaced by Army troops. This would call for a complicated maneuver, occupying for some time a substantial portion of the U.S. Naval forces in Hawaii, thus reducing the Territory’s defensive strength.^[22]

FDR’s War Cabinet Discuss Japanese Troop Movements; FDR Should Report Danger to Congress

Roosevelt scheduled a War Cabinet meeting for noon, November 28. Stimson had asked G-2 (Intelligence) to summarize the information available concerning the movements of the Japanese in the Far East.

The main point of the paper was a study of what the expeditionary force, which we know has left Shanghai and is headed south, is going to do. G-2 pointed out that it might develop into an attack on the Philippines or a landing of further troops in Indochina, or an attack on Thailand or an attack on the Dutch Netherlands, or on Singapore.^[23]

G-2’s paper was “such a formidable statement of dangerous possibilities” that Stimson decided he should discuss it with the president before the War Cabinet meeting.

He went to the White House early that morning, even before FDR had gotten up. Analyzing the situation as he sat on his bed, the president saw only three possible alternatives: “first, to do nothing; second, to make something in the nature of an ultimatum again, stating a point beyond which we would fight; third, to fight at once.” Stimson rejected the first out of hand; he “did not think anyone would do nothing in this situation.” Of the other two, he would choose “to fight at once.” Stimson left, but he returned to the White House again for the scheduled noon meeting with the president, Hull, Knox, Stark, and Marshall.

FDR began the meeting by reading the possible destinations of the Japanese convoy. Then he pointed out one further possibility: if the Japanese were to attack the Kra Isthmus, that could lead to an attack on Rangoon, a short distance away, which would enable the Japanese initially to block the Burma Road. Everyone thought this was very likely.

The picture had changed radically since the last time they had discussed sending an ultimatum to Japan. The Japanese expeditionary force of some 25,000 troops at sea, destined to land somewhere, had changed the situation. Everyone agreed that

if this expedition was allowed to get around the southern point of Indochina and . . . land in the Gulf of Siam, either at Bangkok or further west, it would be a terrific blow at all of the three Powers, Britain at Singapore, the Netherlands, and ourselves in the Philippines. . . . It was agreed that if the Japanese got into the Isthmus of Kra [on the Malaysian peninsula], the British would fight. It was also agreed that if the British fought, we would have to fight. And it now seems clear that if this expedition was allowed to round the southern point of Indochina, this whole chain of disastrous events would be set on foot.

The consensus of the War Cabinet was that this should not be allowed to happen, and the members discussed ways to prevent it. They did not believe the United States should strike at the Japanese force without warning. But they didn’t think we should sit still either and allow the Japanese to proceed. They decided the only thing to do was to warn the Japanese that if the convoy “reached a certain place, or a certain line, or a certain point, we should have to fight.”

The president was inclined to send a personal telegram to the emperor, as he had done with good results at the time of the Panay incident, December 1937^[24] But Stimson pointed out that this would not be a suitable response in this case.

In the first place, a letter to the Emperor of Japan could not be couched in terms which contained an explicit warning. One does not warn an Emperor. In the second place it would not indicate to the people of the United States what the real nature of the danger was.

Stimson then suggested a message from the president to the people of the United States. He thought the best way to do that would be to report to Congress on the danger and on what action we would have to take if the danger materialized. The president acceded to this suggestion. At first he thought of incorporating the terms of his letter to the emperor in the speech. But again Stimson pointed out that a letter to an emperor could not be publicized in that way. The president’s letter should be entirely separate and confidential. Also, his speech to Congress and to the people should be expressed in more understandable terms. FDR agreed and asked Hull, Knox, and Stimson to try to draft such papers.^[25]

War Department Warns Hawaiian Army and Air Commanders

Late in the evening of November 28, the War Department adjutant general wired Short in Hawaii:

“[C]ritical situation demands that all precautions be taken immediately against subversive activities.” Short was advised to

initiate forthwith all additional measures necessary to provide for protection of your establishments comma property comma and equipment against sabotage comma protection of your personnel against subversive propaganda and protection of all activities against espionage stop.

At the same time, Short was to avoid “unnecessary publicity and alarm.”^[26] The cable’s emphasis on sabotage and subversion, reassured Short in his choice of alert.

The next day, Short replied that

full precautions are being taken against subversive activities within the field of investigative responsibility of war department . . . and military establishments including personnel and equipment.^[27]

He also reported on the cooperation in protecting vital installations, such as bridges and power plants being given by Hawaii’s territorial governor, the FBI, and other federal and territorial officers.

The commanding general of the Hawaiian Air Force received a similar cable that day from the War Department. It asked that

all precautions be taken at once . . . to provide . . . protection of your personnel against subversive propaganda comma protection of all activities against espionage comma and protection against sabotage of your equipment comma property and establishments period.^[28]

Again Short felt reassured that the sabotage alert he had initiated was appropriate.

Navy Ordered to Transport Army Planes to Midway and Wake; Hawaiian Forces Weakened

The day before the November 27 “war warning,” Kimmel was advised to prepare to send some planes, men, and provisions from Pearl Harbor to two outlying mid-Pacific islands:

In order to keep the planes of the Second Marine Aircraft Wing available for expeditionary use OPNAV [Chief of Naval Operations] has requested and Army has agreed to station twenty-five Army pursuit planes at Midway and a similar number at Wake provided you consider this feasible and desirable.^[29]

The cabled orders that followed called on Kimmel to transport by aircraft carrier these Army planes, which were to support Navy operations, and to supply the islands with ground personnel, provisions, water, spare parts, tools, and ammunition.

In light of WPL-46, stationing men and planes on Wake and Midway made sense. Wake was a couple of thousand miles west of Hawaii and closer to the Japanese mandated Marshall Islands. An outpost on Wake would extend the area over which reconnaissance could be conducted and would permit the United States to watch more closely what was going on in the Marshalls. At the same time, however, it meant depriving Hawaii of about 50 percent of the Army’s pursuit planes then on Oahu. And the transfer operation itself would occupy for some time the fleet’s aircraft carriers, its main striking defense against air attack.^[30]

Admiral William F. Halsey, Jr., in command of the carrier Enterprise, left Pearl Harbor for Wake on November 28. With him went three heavy cruisers and nine destroyers.^[31]

On December 2 Kimmel responded at length to Stark’s cable. He described some of the difficulties in having the Navy reinforce the outlying islands, and he made realistic suggestions for dealing with them.^[32]

On December 5 Admiral J.H. Newton left Hawaii aboard the carrier Lexington with another contingent of Army pursuit planes bound for Midway. Three heavy cruisers and five destroyers accompanied the Lexington. En route, the patrol planes conducted reconnaissance, covering a much more extensive area than they could have from their Oahu base.^[33]

Also on December 5 Admiral Wilson Brown left Pearl Harbor with Task Force 3, aboard the Indianapolis with six old destroyers converted to sweepers, to conduct landing exercises on Johnston Island in the mid-Pacific.^[34]

Japanese Negotiations Defacto Ruptured

On November 28, two days after the United States responded to the Japanese request for a modus vivendi, Tokyo sent her two Washington ambassadors a cable, which we deciphered and read that same day, commending them for their “superhuman efforts.” However, the U.S. reply had been a “humiliating proposal.” The Imperial Government could “by no means use it as a basis for negotiations.” The Japanese government had, in effect, thrown up its hands, as Ambassador Kurusu had expected it would.

Tokyo added that a report on the American proposal would be along in two or three days and then “the negotiations will be defacto ruptured.” However, the two ambassadors were not

to give the impression that the negotiations are broken off. Merely say . . . that you are awaiting instructions and that, although the opinions of your Government are not yet clear to you, to your own way of thinking the Imperial Government has always made just claims and has borne great sacrifices for the sake of peace in the Pacific. Say that we have always demonstrated a long-suffering and conciliatory attitude, but that, on the other hand, the United States has been unbending, making it impossible for Japan to establish negotiations. . . . From now on do the best you can.^[35]

Japanese Emergency to be Announced in “Winds Code,” Coded Weather Forecast

In the midst of this diplomatic crisis, one of the most important Japanese messages to be intercepted during this period was read in Washington. It had been sent November 19 from Tokyo in the J-19 (consular code), wasn’t deciphered and translated until November 28. “In case of emergency (danger of cutting off our diplomatic relations), and the cutting off of international communications,” a signal will be included “in the middle of the daily Japanese language short wave news broadcast.” Three phrases followed. Each appeared to be a weather forecast, but to each was assigned a special meaning. In an emergency, Tokyo explained, the appropriate phrase “will be repeated twice. When this is heard please destroy all code papers, etc. This is as yet to be a completely secret arrangement.”^[36]

This new intercept became known as the “Winds Code” message. The three phrases and their meaning were: HIGASHI NO KAZE AME (East wind rain): Japan-U.S. relations in danger; KITANO KAZE KUMORI (North wind cloudy): Japan-U.S.S.R. relations in danger; and NISHI NO KAZE HARE (West wind clear): Japan-British relations in danger.

When our people read this message, orders went out immediately from both the Army and the Navy to their intercept stations throughout the world, asking them to monitor Japanese short-wave news broadcasts. Because weather was unpredictable and atmospheric conditions often interfered with radio transmissions, reception at our intercept stations was erratic. Therefore, the call went out to all our monitoring stations from Rear Admiral Leigh Noyes of Naval Communications^[37] and from General Sherman Miles of the Army’s Intelligence Division urging the code clerks to listen for the phrases.^[38] Three-by-five cards with the three phrases were prepared and distributed:^[39]

HIGASHI NO KAZE AME (East wind rain—war with the U. S.)

KITANO KAZE KUMORI (North wind cloudy—war with the U.S.S.R.)

NICHI NO KAZE HARE (West wind clear—war with Great Britain.)