Following the hard-won conquest of the Gilbert Islands in 1943, the rising tide of U. S. naval power surged over the Marshalls in the opening months of 1944.
Seizure of the Marshall Islands represented the coming of age of U. S. amphibious power. Tarawa, two months earlier, had demonstrated that amphibious assault could be forced home against opposition by resolute troops. Tarawa had also proven that the principles of amphibious assault, perfected in the 1920's and 1930's by the U. S. Marine Corps, were sound. It now remained to apply those battle-tested doctrines, plus the inevitable lessons learned from their initial application, in a larger arena, against stronger enemy forces, and on a scale of both attack and support previously never attempted.
Some Geography and History
The Marshall Islands1 consist of 32 coral atolls and 867 reefs which span ten degrees of latitude (14°30' N. to 4°30' N.) and 800 square miles of ocean. They lie in a double chain along a common northwesterly axis some 15 degrees west of the International Date Line. The two chains are entitled Ratak (Sunrise) and Ralik (Sunset), in accordance with their eastwest dispositions. Each atoll is an enclosed or semiclosed reef on which islands and islets of coral, sand and rock have been built by the action of surf, tide and wind. They range in size from pinpoint islets (Kili Island) to Kwajalein, largest atoll in the world.
Table of Distances from Kwajalein Atoll
The Marshalls operation was thus an inevitable sequel to that in the Gilberts, yet by no means the same. Moreover--and this meant much to the Marines, seamen, and soldiers of the Pacific forces in 1943--attack on the Marshalls marked our first penetration of enemy territory; up to this point, in the Solomons and the Gilberts, we had regained ground lost in 1942. Now, at length, the United States was making its first step forward into the islands which, by mandate at any rate, had been Japanese before 1941.
Approximately 2,000 such islands and islets comprise atolls of the group, never exceeding 20 feet in elevation. Most of the islands are fronded with coconut palms, breadfruit, or pandanus, but relatively few are large enough to have names, and even fewer are large enough to support native populations. The climate is steamy, with frequent rain squalls and showers. The first known white man to sight the Marshall Islands was a Spaniard, Garcia de Loyassa, in 1526, and he was followed by his fellow
countryman, Alvaro de Saavedra, three years later. Spain assumed nominal possession of the islands at the same time she annexed the Carolines and Marianas, in 1686, but they were virtually forgotten until 1788 when two Englishmen, Captains Marshall and Gilbert, explored the Marshall atolls and those of a neighboring group which were, logically, named the Gilberts. By 1824 all islands within the Marshalls had been discovered, and the natives came increasingly into contact with whalers, merchants, missionaries, and explorers.
In 1878, Germany, in a belated quest for empire, became interested in Spain's Pacific possessions, and encouraged her energetic traders to establish themselves in the Marshalls. Twenty-one years later, Spain sold the Carolines, Marianas (less Guam), and Marshalls to Germany for $4,000,000, and the latter power took formal possession. German colonization was interrupted in 1914 when Japan, ostensibly acting as an ally of Great Britain, moved in occupation forces. The League of Nations in 1920 recognized Japan's de facto sovereignty by giving that nation a Class "C" mandate over the Marshalls, a mandate which specifically prohibited military and naval installations. After throwing over the League in 1936, however, the Japanese did not return the Marshalls to the international organization, but instead proclaimed absolute sovereignty over them. Foreigners had never been encouraged to travel within the mandated islands, and now, with formal annexation, the Japanese rigidly excluded them.
The Japanese administered the Marshall Islands (except for Eniwetok and Ujelang) by the Jaluit Branch Bureau of the South Seas Administration (Nanyo-Cho), while the two excepted atolls came under the direction of the Ponape Branch Bureau. These branch bureaus in turn were under a director who presided at Koror Town in the Palaus, and he in turn answered to the Minister of Overseas Affairs, Tokyo. Local administration among the natives was handled by village chiefs and headmen.
THE MARSHALLESE lived a quiet and simple life at the turn of the century. (Photo courtesy of the National Archives).
The last available population figures (1937) for the Marshalls listed 10,068 natives (Kanakas) and 493 Japanese under Jaluit Branch Bureau. The natives were and are Micronesian, more nearly resembling the Polynesians of Hawaii and Samoa than the Melanesians of the Fijis and Solomons. The Kanakas subsisted by fishing, marginal truck-farming and as little paid labor under the Japanese as they could be compelled to perform.
From a military standpoint the Marshall atolls of importance in 1943 included Mille,2 Majuro, Maloelap, and Wotje in the Ratak chain; and Jaluit, Eniwetok, and Kwajalein3 in the Ralik chain. (See Map 1, Map Section.) Bikini, in the latter group, was to attain later fame as a testing ground for atom bombs, but as far as 1943-44 operations were concerned, Bikini figures hardly at all.
ORANGE and "Z"
To military planners, both Japanese and American, the strategic importance of the Marshalls had long been recognized. As seen from Japan, these wind-blown coral atolls constituted an unsurpassed geographical shield for the then-mysterious "Mandated Islands"--a shield which might serve as a line of departure for attack,4 or an outpost line of resistance in the defense.
Conversely, to U. S. naval planners the Marshalls represented a menacing extension of Japanese power toward the eastern Pacific and a standing hazard to lines of communication into the South and Southwest Pacific. Any drive
MARSHALL ISLANDS NATIVES used unique crafts, such as the one above, for fishing. (Photo courtesy of National Archives.)
toward the Japanese maritime "heartland" in the Carolines and Marianas--themselves in turn obvious springboards for final assault upon Japan--must encounter the unsinkable "anchored aircraft carriers" of the Marshalls.
In 1921 the Marine Corps' almost legendary war planner, E. H. "Pete" Ellis5, (then a major), drew up a plan entitled Advance Base Operations in Micronesia. Major Ellis' portfolio was approved by Major General Commandant John A. Lejeune on 23 July of that year. It stipulated that the Marine Corps
. . . be prepared to accompany the Fleet and reduce enemy resistance in Marshall Islands; to hold there a temporary base for our Fleet and to deny the use of the remaining available islands or atolls suitable for bases to the enemy.
Ellis visualized the seizure of Eniwetok, Ujelang Atolls, Wotje and Jaluit Atolls with a
THIS IDYLLIC SCENE in Jaluit lagoon was photographed some 44 years before the Marshall Islands became a battleground. (Photo courtesy of National Archives.)
total of five Marine regiments. For the seizure of Eniwetok he predicated a reinforced infantry regiment of virtually identical strength with that ultimately employed.
Perhaps the best known prewar U. S. plan was ORANGE, which conceded initial loss of the Philippines in a war involving only the United States and Japan. ORANGE set forth that the Fleet would drive westward through the Marshalls and Carolines and on to recapture of the Philippines. The Navy estimated that 25,000 trained troops, with an additional 50,000 in reserve, would be required to reduce the two island groups.6
With the beginning of hostilities in 1941, however, the United States was forced onto a strategical defensive which continued until mid-1943. By that time, victories at Midway and in the South and Southwest Pacific,7 as well as a drive on the Aleutians, were significantly reversing the status of the two Pacific opponents. Untouched thus far were the reaches of Central Pacific, the most direct route to Japan. As the advantages of men and material shifted to the United States, however, it became evident that this area would not remain inviolate for long.
To protect this approach and establish an airtight strategic position, the Japanese Navy, in cooperation with the Army, formulated the "Z" Operation Plan during May 1943.8 This plan visualized a lengthy defensive front across the Aleutians, Wake, Marshalls, Gilberts, Nauru, Ocean, and the Bismarcks. Local commanders were responsible for their own security, but the crux of the plan was to base the Combined Fleet at Truk and send it to the assistance of any threatened link in the chain.9
But by the end of September 1943 Allied gains required a modification of the Japanese plan. Landings at Vella Lavella, Munda, Lae and Salamaua, in addition to naval and air losses at Rabaul, caused the Emperor's men to pull in the perimeter and set up a new defensive line. The Bismarcks and Gilberts-Marshalls were written off, the line then joining the Kuriles-Marianas-Carolines. The islands thus removed from the questionable security of the "Z" Plan were not abandoned, however. Quite the reverse. They were slated for reinforcements and supplies in order to fill the mission of forward bastions of the new perimeter. Their function was to impede, and if possible
LIEUTENANT COLONEL EARL H. ELLIS drew the first attack plan for the Marshalls in 1921.
stop, any westward attack which might threaten the inner defenses. To this end the defenders must strengthen their positions and prepare themselves to fight to the death.
"Thus We Get On With The War"
As if endorsing the soundness of Japan's estimate of events, the Combined Chiefs of Staff (CCS) at the TRIDENT Conference (Washington, May 1943) decided to seize the Marshalls, as well as to move against other points on the enemy's Pacific perimeter.10 At that time the CCS agreed that a major 1943-44 strategic objective in the Pacific should be to open an Allied line of communications to the Celebes Sea, and to secure and shorten a line to the Southwest Pacific. To implement
this the planners specifically approved an undertaking to seize the Marshall and Caroline Islands.11 To General Douglas MacArthur's argument that every resource be concentrated on the New Guinea-Mindanao axis with its asserted advantage of shore-based air, the CCS said: (1) the enemy could concentrate against a single line of advance; (2) simultaneous offensives in the Central and Southwest Pacific would protect the latter area from flank attack; (3) simultaneous offensives would deceive the enemy as to the ultimate route to be taken against the Empire itself; (4) aircraft carriers would provide concentrations of aircraft at any desired point and time.12
Thus in June 1943 the Joint Chiefs of Staff (JCS) directed Admiral Chester W. Nimitz, Commander-in-Chief Pacific Ocean Areas (CinCPOA),13 to submit a plan for operations against the Marshalls. In response to this directive on 1 July Nimitz submitted a tentative and somewhat exploratory concept for an operation by the Pacific Fleet as well as by ground
PALM-COVERED NAMUR two months before the 24th Marines landed there. (Navy photo.)
and air elements under his command.14 This exchange was followed three weeks later by a JCS directive to the admiral that he prepare to seize the Gilberts by 1 December 1943, preceding additional operations in the Marshalls on 1 January 1944.15 One month later Admiral Nimitz and his staff had completed and submitted an outline plan for the Marshalls.16 In this, CinCP0A assumed the success or continued progress of operations in the Gilberts (GALVANIC) and in the New Guinea-New Britain (CARTWHEEL) area. He likewise summarized the factors which now favored success in the Marshalls:
The present availability of United States strength and means.
The corresponding strengthening of our own lines of communication and resultant threat to the enemy's lines of communication.
The possibility that a thrust into the Marshalls might precipitate fleet action on favorable terms.
The timing, which would probably cause the Japanese, in confusion, to divide their forces among various theaters.
"Thus," he concluded, "we get on with the war."
Contrariwise, however, unfavorable factors existed and merited consideration in planning for the Marshalls:
The problem of obtaining accurate and timely information.17
Difficult fleet logistic problems because of the lack of bases west of Oahu.
ADMIRAL NIMITZ, CinCPac-CinCPOA, conceived the bold plan to by-pass the heavily defended atolls and strike Kwajalein in the heart of the Marshalls. (Navy photo.)
Possible lack of surprise.
The necessity for rapid training of our own forces.
Dependence for air superiority wholly upon carrier aircraft until bases could be established ashore.
In summary, the CinCPac-CinCP0A Marshalls plan embodied these basic elements:
Simultaneous seizure of key islands in Kwajalein, Wotje, and Maloelap Atolls, coupled with neutralization of Jaluit and Mille.
Mounting and staging from Oahu, the Gilberts, and the South Pacific.
Intensive photo reconnaissance and preliminary air strikes from the Gilberts, Baker, and from Nauru (which was then
an intended target in the Gilberts scheme).
Operations to accomplish these ends to require approximately 35,000 assault troops backed by a major fleet.18
Central Pacific strategy was considered by the Combined Chiefs of Staff at the QUADRANT Conference (Quebec, August 1943) where it was decided that the Marshalls should immediately follow the Gilberts operation. On 1 September, the Joint Chiefs dispatched a directive to Admiral Nimitz for operations in the Marshalls. The wording of this order was almost identical with the earlier CinCPOA plan except that an allocation of actual troops and naval forces was made to accomplish the mission. In addition, a new phase--of considerable significance, as it turned out--was added to the plan as proposed, namely, that upon completion of the Marshalls task, Admiral Nimitz must "seize or control Wake, Eniwetok and Kusaie."
Troop allocations for the Marshalls consisted of the 4th Marine Division (training on the West Coast); the 7th Infantry Division (in Hawaii); the 22d Marines (reinforced) (in Samoa), augmented by the myriad base defense and development units required to realize the fruits of amphibious assault. Later the 106th Infantry Regimental Combat Team was temporarily detached from the 27th Infantry Division in Hawaii and added to the force.
Within three weeks, on 22 September, Admiral Nimitz' staff had completed the initial planning required on area level, and the Marshalls project then passed for execution to the Commander, Central Pacific Force, Vice Admiral Raymond A. Spruance.19
Table of Contents ** Previous Chapter (Foreword) * Next Chapter (2)
1. Unless otherwise indicated, data on terrain, hydrography, physical characteristics and history of the Marshalls are from Sailing Directions for the Pacific Islands, Vol. 1, 1938, H. O. 165; The Pacific Islands Handbook, by R. W. Robson, Macmillan Co., 1945; Guide to the Western Pacific, CinCPac-CinCPOA Bulletin No. 126-44, and V Amphibious Corps G-2 Study of the Theater of Operations: The Marshall Islands, 26Nov43.
2. Like the majority of Pacific islands, there were many ways of spelling the names of the Marshall atolls. For instance, Mille appears as "Milli" and "Mill". This narrative will follow spelling used by CinCPac-CinCPOA and VAC at the the of the operation.
3. Kwajalein Atoll includes Kwajalein Island, scene of important operations in the Marshalls campaign. To prevent confusion, this narrative will therefore refer to Kwajalein Atoll as such, and to the islands merely as Kwajalein. In the operational cant of code names, Kwajalein Atoll became CARILLON and Kwajalein became PORCELAIN.
4. The Marshalls did, in fact, provide the springboard for Japanese Fourth Fleet operations against Wake and the Gilberts in 1941. See LtCol Robert D. Heinl, Jr., The Defense of Wake, monograph prepared by Historical Section, USMC, 1947.
5. The most complete extant accounts of Ellis' career, compiled entirely from official sources, appear in Saturday Evening Post, 23Nov46: "The Marines' First Spy," by Maj John L. Zimmerman, USMCR; Marine Corps Gazette, Nov50: "Personalities-Men Who Differed," by Maj Frank 0. Hough, USMCR.
6. Memo from Adm H. R. Stark to SecNav, 12Nov40. ORANGE gave way to a series of RAINBOW Plans after Japan joined the Axis, and the United States moved to closer accord with Great Britain.
7. LtCol Robert D. Heinl, Jr., Marines at Midway; Maj John L. Zimmerman, The Guadalcanal Campaign, hereinafter cited as Zimmerman; Maj John N. Rentz, Marines in the Central Solomons, monographs prepared by Historical Branch, USMC.
8. A companion, "Y" Operation Plan, was formulated at the same time for Japan's western frontier.
9. The Campaigns of the Pacific War, United States Strategic Bombing Survey, GPO, 1946, pp. 6-8, 191, hereinafter cited as USSBS.
10. The War Reports of General Marshall, General Arnold and Admiral King, Lippincott, 1947, p. 158.
11. CCS 239/1 "Operations in the Pacific and Far East in 1943-44," a Joint Chiefs of Staff (JCS) paper approved by the CCS 21May43.
12. Samuel Eliot Morison, History of United States Naval Operations in World War II, Vol VII, Aleutians, Gilberts and Marshalls: Little, Brown and Co., 1951, p. 81, hereinafter cited as Morison.
13. Nimitz wore two hats as Commander-in-Chief Pacific Fleet (CinCPac) and CinCPOA. The former title represented his naval command, the latter his command over the North, Central and South Pacific Areas under the JCS. As his opposite number General MacArthur held the title of Commander-in-Chief Southwest Pacific Area (CinCSWPA).
14. CinCPac serial 0415 to Commander-in-Chief United States Fleet (CominCh), 1Jul43.
15. JCS to CinCPOA, 202204 July 1943, p. 35 in IV. F. Craven and J. L. Cate, The Army Air Forces in World War II, Vol IV, The Pacific--Guadalcanal to Saipan, University of Chicago Press, 1950, hereinafter cited as AAF in WWII.
16. CinCPac serial 00151 to CominCh, 20Aug43, hereinafter cited as CinCPac serial 00151. Unless otherwise noted succeeding references within this chapter to the plan are taken from this source.
17. The intelligence problems created by an offensive into the Marshalls were peculiarly troublesome because of Japan's closed-door policy in that area for many years previously. Not even the scantiest information was available, let alone the mass of detail upon which amphibious planners must depend.
18. Troop requirements were broken down into approximately 21 battalion landing teams with appropriate supporting units, and four defense battalions. Combat ships would total 13 battleships, 19 aircraft carriers, 15 cruisers, and 95 destroyers.
19. CinCPac serial 00190 to ComCenPac, 22Sept43.