I
One of the major military developments of the war just past was the demonstration that amphibious assault against a defended beachhead—one of the prewar "impossibilities"—could succeed in the teeth of every defense which our enemies ever found it possible to muster.
This development, world-wide in its effects, was in large part the outgrowth of the thought and effort devoted to the subject by officers of the United States Marine Corps, stemming in certain respects from concepts which antedated even World War I.
Closely related, both historically and functionally, to the evolution by Marine officers of the highly developed science of amphibious operations, there arose at the same time a parallel concept, that of the Fleet Marine Force.1 Indeed it might truthfully be said that the logical history of modern amphibious technique is in many ways the story of the Fleet Marine Force. The ideas of Marine Corps amphibious thinkers produced the Fleet Marine Force; this unique unit in turn gave body and substance to the doctrinal theories of its creators; and the interaction of the two combined in substantial measure to make possible the victorious beachheads of World War II.
To be sure, landing operations by Marines have been an accepted commonplace throughout their history. Since the U. S. Marines' first landing at Nassau in the Bahamas in 1776, the Corps executed as a matter of course some 180 landing operations between 1800 and 1934, followed by more than a hundred during the course of the recent war.
But there is a great distinction to be drawn between the casual landing of early days and the complex technique of amphibious assault as we understand it today. This development largely spanned the period from the beginning of this century through 1940.
One of the first landings of a modern character was that at Guantanamo Bay in Cuba in 1898.2 The mission of this expedition was the seizure of a major naval base for Fleet operations in the blockade of Santiago, and the instrument employed was a regularly organized battalion of Marines (which included Marine infantry and field artillery units) rather than the provisional battalion based on ship's detachments which had hitherto been our characteristic form of organization.
Succeeding years saw increased use of organized battalions and regiments based afloat in transports, but the possible use of the Marine Corps in its present organized form appears not to have received great attention until shortly before World War I when the growth of the U. S. Navy placed the United States among the world's great naval powers.
In any case, shortly thereafter the Advanced Base Force, U. S. Marine Corps, a permanent field force, was organized for the occupation and defense of advanced naval bases. Even here the idea of defense appears paramount and was probably a corollary of the unexpressed concept that offensive operations were still the function of ship's detachments. However, Nicaragua (1912), Vera Cruz (1914), and Haiti (1916) saw these advanced base units deployed in offensive operations rather than in base defense, and it comes as no surprise to find in the first two issues of The Marine Corps Gazette in 1916 leading articles by Majors John A. LeJeune and John H. Russell (both of whom subsequently became Commandants of the Corps) advocating employment of Marines in the form of a fleet Marine force and pointing out the repercussions and implications of recent reverses at Gallipoli.
The active renaissance of Marine Corps amphibious studies, however, can be very definitely dated from the year 1921, when the Corps established its plan, its forces, and its schools for the express purpose of reducing landing operations to a scientific and technical basis.
In that year there was produced at Marine Corps Headquarters a basic war plan which is believed to be one of the most remarkable documents of its kind ever written. It was largely the work of Lieutenant Colonel Arthur E. Ellis, U. S. Marine Corps, a brilliant staff officer who was soon to disappear in 1923 while "travelling" in the Japanese Mandates of the Pacific Islands. This "War Portfolio" outlined the Pacific war to come, predicted its dimensions, and forecast with remarkable accuracy the part to be played by the Marine Corps in making effective our superior naval power. The capabilities and roles of new weapons, including the carrier, submarine, torpedo plane, and long-range bomber, were foreseen and wisely projected. The need for special amphibious landing craft and fleets of attack transports was noted. Above all, the Marine Corps "War Portfolio" foretold the step-by-step base seizure that would be entailed in the effort to advance our sea power westward. Even the detailed assessment of forces required would appear amazingly accurate twenty-three years later; for example, Colonel Ellis stated that a reinforced regiment would be required to seize Eniwetok Atoll. This was the exact force employed for the successful attack in 1944.
The full effect of this remarkable blueprint cannot be completely assessed even today, but the steps taken during the same year of 1921 to implement the "War Portfolio" indicate that it was received with utmost respect.
The Advanced Base Force had passed out of existence in 1917 in response to the practical necessities of World War I, but the idea was not forgotten. It was revived again in 1921 when the East and West Coast Expeditionary Forces were organized for service with the U. S. Fleet. Here the important distinctions to be observed are that (1), the new organizations were offensive landing forces, and that (2), they were expressly integrated with the U. S. Fleet as instrumentalities in the application of sea power.
In the same year there was established at Quantico, Virginia, that necessary complement to the field forces, the Marine Corps Schools, devoted to the science of amphibious warfare.
Over the ensuing years the reports of fleet landing exercises (the annual large scale amphibious maneuvers of the Fleet and its Marine force) and the teachings and writings of the Marine Corps Schools are a record of a parallel approach to a common problem. There was recognition of the fact that the subject of landing operations needed the same applied study and reduction to technique devoted to other forms of warfare. There were mistakes and false beginnings, but there was also progress. Starting with Gallipoli as the classic object-lesson, and in the entire absence of a source of positive material except the Ellis plan, the problem was dissected into its component parts by segregation and analysis of the major mistakes made in the Dardanelles, followed by a search for methods of correction. The inquiry directed itself quite naturally into these subdivisions:
- The failure of command
- The lack of means of control
- The lack of special material and equipment
- The failure of communications
- The inadequacy of naval gunfire support
- The failure in the field of logistics.
From these analytical beginnings, there were established lines of constructive effort and investigation which, within a few years, gave to the Navy and Marine Corps, through its schools, the following:
- A philosophy of parallel command relationships
- The modern technique of a controlled ship-to-shore movement
- Experimental development of landing craft and landing vehicles
- Ship-to-shore communications
- Doctrine of naval gunfire support
- The fundamentals of embarkation and combat loading of transports
- Fundamentals of shore party organizations.
These matters were well developed and reduced to writing by 1929, when the Marine Corps schools issued a series of tentative landing force doctrines which, less than two decades later, would culminate in finished form among the basic joint technical documents employed in the prosecution of amphibious operations against the Axis powers.
During the 1920's, while the thinkers and teachers at Marine Corps Schools restudied and dissected the amphibious operations of the past, the majority of the Corps was employed to capacity in major overseas missions. Marine brigades were bringing stable government to Haiti, then under United States protectorate; they were quelling savage banditry in Nicaragua; and in China they were helping to protect not only American but all foreign nationals from the hazards of the civil wars and the Japanese aggression which even then menaced the Orient. As a result, the East and West Coast Expeditionary Forces perforce remained largely as paper units.
By 1933, however, the pressure of these duties had measurably slackened, and it became possible to allocate troops to what had long been realized was the primary military raison d'être of the Corps: expeditionary forces for service and training as an integral part of the United States Fleet.
On December 7, 1933, the Secretary of the Navy, Mr. Claude Swanson, at the urgent recommendation of the Major General Commandant of the Corps, John H. Russell, signed Navy Department General Order 241, a document in which for the first time the title "Fleet Marine Force" was used, and in which the concept of this force and its employment was fully expressed. On the next day, December 8, General Russell promulgated Marine Corps Order 66, which set forth implementing instructions regarding the organization and doctrine of the Fleet Marine Force.
As organized in 1933, the Fleet Marine Force (or "FMF," as it is habitually styled among U. S. Marines) comprised two brigades of equal strength, one stationed at San Diego, California, for service with Pacific elements of the U. S. Fleet, and the other at Quantico, Virginia, for Atlantic service.
In size perhaps, and in organization certainly, the title "brigade" was, by the accepted military terminology of the day, a misnomer for either of these units. The nearest present-day parallel—a descendant, in fact, of these brigades—is what in amphibious operations we now term the regimental combat team, or "RCT." Like the RCT, the two Marine brigades (the 1st was at Quantico, the 2d at San Diego) were balanced forces of the combined arms built around an infantry nucleus, a peace-strength rifle regiment. In each brigade the rifle regiment was supported by a battalion of light artillery; service troops; engineers; antiaircraft in light of the rudimentary standards of the day; signal communication troops trained not only in the conventional techniques of military communications ashore, but in the distinctly more complex operations of Fleet radio and visual communication; and Navy medical elements trained and organized for service ashore. As funds and authorized strength permitted, tank and chemical troops were added, and, at all times, though not organic within the two brigades, Marine Air Groups were stationed at Quantico and San Diego, where their pilots could not only train year in and year out as integral parts of the Fleet air arm, but could master the distinct and essential technique of close air support of troops during landing operations, employing know-how gained in Haiti and in Nicaragua, where Marine pilots had perfected the art of dive-bombing and Marine Corps aviation had carried on the first airborne operations ever to provide major and continued support to U. S. troops during combat operations.
Three predominant aspects marked the FMF of 1933 as novel within the framework of American arms. Virtually all might be styled philosophical attributes of the new Marine force, and all found expression in its doctrines of training and potential employment:
(1) The fact that it was singly and openly organized, equipped, and trained for landing operations incident to naval campaigns. A simple example of this attribute was that its light artillery, rather than being the conventional 75 mm. field gun then standard for comparable Army units, was instead a pack-howitzer originally designed for mountain use. The reason for this was that the howitzer could be broken down and manhandled from a ship's motor-launch, through surf if necessary, and in the hands of the cannoneers. Transportation was limited, not only by the fiscal stringencies of peacetime, but by dimensions and weights made to conform to what ships' holds, boats, and booms could handle.
(2) The force, small as it was, was never skeletonized or cadred down to the extent that it was not capable of very rapid embarkation in useful combat units and movement by sea, thus retaining at all times a high quality of readiness and strategic mobility well suited to the policy of a maritime nation whose Fleet constituted a first line of defense.
(3) Realizing how garrison-duty can sap the effective combat-training of any tactical unit, the Marine Corps had from the outset made every effort to draw sharp distinction between FMF units and what became known as "post troops"—for example, the units needed for normal garrison, security, maintenance, and similar duties which so often swallow up opportunities for tactical training. At each post where FMF troops were stationed, overhead post troops were likewise maintained so that Fleet Marine Force training might proceed unhampered. Individual Marines, of course, were rotated between FMF and non-FMF duties so that all members of the Corps were fully trained in combat roles.
As an adjunct to the Marine Corps Schools which had generated the rationale of the Fleet Marine Force, another agency, primarily concerned with the study of the materiel problems of amphibious operations, was plainly needed. In 1933, the golden year of the Fleet Marine Force, the Marine Corps Equipment Board was therefore formed. This was the first professional body in the United States to devote its entire time and study to the development of materiel suitable for the use of troops in amphibious warfare.
This board, seeking ideas where they were to be found, cooperated with Navy and Army agencies in the test and development of equipment for the Fleet Marine Force. Its ideas went far toward the early design of suitable landing craft and toward the shaping of heavy materiel specifications to the limits of tonnage and dimensions then obtaining in landing operations. Through the unceasing urge for development of a reef-crossing vehicle so obviously a prime desideratum for the coral-ringed atolls of Colonel Ellis's "War Portfolio," the Board sponsored and pioneered the now-renowned LVT or "Alligator," the amphibian tractor which carried troops across every beachhead from Tarawa to the Rhine.
Within two years after the organization of the Fleet Marine Force, funds were for the first time available, in 1935, to permit a full-dress amphibious landing exercise employing the Fleet Marine Force in its role as a part of the Fleet. These maneuvers, carried out in January, 1935, were executed by the 1st Marine Brigade, on the island of Culebra, P.R., and it was here that the new doctrines and organizations received their first field tests, involving not only the "assault" landing of Marines against a "defended" objective, but the establishment of effective ship-shore communications; the logistic support of expeditionary forces ashore by the Fleet, and the very elementary beginnings of a practical means of harnessing the immense residual fire-power of ships' guns for accurate employment against shore targets.
Repeated annually from 1935 through 1939, these Fleet Landing Exercises (FLEX) grew in scope, provided sure means of discovering the flaws of technique and theory, and enabled materiel to be put to practical test. Equally important, they made certain that the units of the tiny Fleet Marine Force—which even by 1939 included but 4,991 Marines—were brought to a keen edge of training for their primary mission, and that both officers and men were as much at home aboard assault shipping as in barracks ashore.
Not only as a measure of convenience and economy, but to insure familiarity by the Fleet and Fleet Marine Force with amphibious conditions in both the Atlantic and Pacific, the Fleet Landing Exercises were alternated in locale between the Caribbean, where the Culebra-Vieques area was available adjacent to the Virgin Islands, and the Eastern Pacific, where the Hawaiian Islands and San Clements Island served similar purposes.
By 1940, as a result of thinking at Marine Corps Schools and practical field training in the Fleet Marine Force, the following essentials of amphibious technique existed not only on paper but in vigorous being:
- The Fleet Marine Force. A balanced expeditionary component of ground troops which, as much an element of the Fleet as its submarines or aircraft carriers, was ready for overseas operations and trained for amphibious assault
- Doctrines for naval gunfire support and close air support during landing operations—the first practical means ever worked out to permit the attacker, even in amphibious assault, to gain without artillery the fire-superiority which is needed to overbalance the inherent advantages of the defender.
- Logistic and communications doctrines and troops evolved for the peculiar purpose of bridging wind and water between ship and shore.
- Specially organized base-defense units designed to possess very high strategic mobility for the rapid occupation and defense development of overseas bases so that the other elements of the Fleet Marine Force need not be dispersed or immobilized in defensive roles.
Needless to say, all these developments in technique and organization had not taken place on an unwritten basis. As early as 1935, the staffs at Marine Corps Headquarters and the Schools had collaborated in preparation of a "Tentative Landing Operations Manual," which in 1938 was formally adopted by the U. S. Navy under title of FTP-167, "Landing Operations Doctrine, U. S. Navy." Throughout the war this volume, as revised in 1940, served as the basic United States doctrine for amphibious operations.
In 1941, the Fleet Marine Force was called upon in two widely differing ways to demonstrate its capabilities. The first and perhaps the more dramatic instance was the occupation of Iceland during July of that year. The second was its assumption of the role of de facto troop training unit for other American units in the amphibious techniques which had been so patiently devised and mastered during the quiet years of peace.
Iceland, garrisoned by British forces including Royal Marines since May, 1940, had become critical not only in the Battle of the Atlantic, but to the possible defense of the Western Hemisphere; and the importance of its remaining adequately secured was fully appreciated by President Roosevelt. For this mission, and with no warning, a provisional Marine Brigade was organized on June 16, 1941, from available Fleet Marine Force units. Less than a week later, on June 22, the entire brigade had sailed from Charleston, South Carolina, and on July 7, more than 4,000 Marines were disembarking at Reykjavik3 to reinforce the British garrison and to act as advance party for eventual follow-up movement to Iceland by U. S. Army units as they subsequently became ready and available for this duty.
This oversea movement by a task organization thrown together on short notice for the mission (essentially in support of Atlantic Fleet operations, be it noted) was classic for the Fleet Marine Force, and amply demonstrated its capabilities.
Less in the public eye than the Iceland affair, but of considerably greater eventual importance, was the formation almost contemporaneously, on June 6, 1941, of the Amphibious Corps, Atlantic Fleet, a provisional Corps consisting of the 1st Marine Division, the 1st Army Division, Marine and Army air components, commanded by a Fleet Marine Force staff under Major General Holland M. Smith, U. S. Marine Corps. This Corps actually was an embodied means for imparting large-scale amphibious training to Army formations, such as the 1st Army Division, which had had no previous indoctrination. Virtually all of 1941 was devoted to bringing the Army division to a satisfactory level of proficiency, and to accustoming all hands, including the amphibious staffs and units of the Atlantic Fleet, to large-scale operations of this type. During this period, especially noteworthy practical advances were made in shore party and amphibious logistic methods, the results obtained being finally embodied in FTP-211, "Ship to Shore Movement," basic in this particular field. Another great field of practical development was the naval shore-bombardment exercises carried on under joint sponsorship of Maxine artillery and Navy gunnery experts at Bloodsworth Island in Chesapeake Bay. These firings constituted the first really large-scale test of the naval gunfire support doctrines4 embodied in FTP-167, and laid the foundation for the eventual widespread and effective use of naval fire-support not only by Marines in the Pacific, but by other American forces throughout the world.
The onset of war in December, 1941, only heightened the already brisk tempo of training within the Amphibious Corps, Atlantic Fleet, as well as within the shortly-to-be-formed Amphibious Corps, Pacific Fleet, similarly organized from Fleet Marine Force elements and staffs. In addition to preparing Marine units for the seizure of Guadalcanal, the two amphibious corps provided the necessarily hasty amphibious training for the 1st, 3d, and 9th Army Divisions, together with numerous smaller units; these three divisions were the first units of the Army to be so trained, and constituted the entire assault landing force of U. S. infantry divisions in the North African operation of 1942.
Over and above the foregoing divisions, before the war had been completed similar amphibious training would be provided by the Marine Corps to the following additional Army divisions and other major units: 7th Infantry Division; 81st Infantry Division; 96th Infantry Division; 97th Infantry Division; and Amphibious Training Force 9 (7th Infantry Division plus 184th and 53d Regimental Combat Teams, and the 13th Canadian Brigade), a provisional composite corps for Aleutian operations.
With such a record as this, it could truly be said that, had the Fleet Marine Force. never fired a shot in anger, its existence had already been well justified.
How the FMF met its test of battle, we shall now see.
II
Before we consider the combat operations of the Fleet Marine Force in the Pacific War, it might be wise to outline its growth from peace strength so that the reader may have some idea of the military dimensions of the subject.
As we have seen, the peacetime FMF consisted of two so-called brigades (really expanded regimental combat teams each composed of one rifle regiment together with a staff and nucleus of all the combined arms which one finds within a division).
In order that Marine expeditionary forces might be readily available for service with either the Atlantic or Pacific Fleet, one brigade, the 1st, was based on the East Coast at Quantico, Virginia, while the 2d Marine Brigade normally based at San Diego, California. By 1941, in the very shadow of hostilities, the 1st Marine Brigade had already been ordered to Guantanamo Bay, Cuba, for expansion to form the 1st Marine Division, while the 2d Marine Brigade was also in process of conversion to a division of like numerical designation. Because both "brigades" contained cadres of every specialist element found in the war-strength division, the changeover did not present the difficulties which might have been anticipated.
Before the end of 1942, both divisions had seen action against the Japanese, and the 3d Marine Division was forming. Reinforcing special units, ranging from the hard-working defense battalions5 to corps artillery battalions and other types of higher-echelon troops, were being organized at maximum rate. Marine Corps aviation, interchangeable in equipment and training with the Navy's carrier-squadrons, was likewise expanding by leaps and bounds. By the end of 1943, the 4th Marine Division had been formed; in 1944, the 5th was in training, and by early 1945, the 6th Marine Division had been organized from an expanded version of a provisional Marine brigade which had seen distinguished service in the South Pacific and the Marianas.
In 1944 the Fleet Marine Force was in effect stabilized as a sort of field army consisting of two corps ("amphibious corps" was their complete and correct title), the III and V Amphibious Corps, each consisting of three Marine Divisions and all supporting troops needed for a corps. In addition, under Fleet Marine Force control, there were maintained all the manifold specialist and service units required to support two corps in amphibious operations. The Fleet Marine Force itself was a type-command, so-called, within the U. S. Pacific Fleet, so that the Commanding General of the FMF was as much in control of all Marines within the Fleet as the Commander Battleships was in charge of all battleships. At no time was it ever forgotten that the Fleet Marine Force was essentially a Fleet element, necessary and indispensable for prosecution of the naval campaign.
With the foregoing structure, at a strength of almost 200,000 Marines, the Fleet Marine Force fought many of its greatest battles, and in this form it concluded the Pacific War. Let us examine the methods and manner in which it fought.
The Fleet Marine Force spearheaded two of the major amphibious campaigns of the Pacific War: the South Pacific campaign and the Central Pacific campaign. These differed radically, not only in terrain and nature of operations, but in strategic concept.
The war in the South Pacific was in some senses a holding attack, an offensive-defensive which only at the last attained the status of a true offensive, and then only for the reduction of outer works in the deep Japanese system of South Sea bases. In the South Pacific, deadly as were the hazards of malaria and merciless jungle, it was almost always possible to "hit 'em where they ain't"—to land against light opposition by choosing a point of attack which the enemy could not defend.
In the Central Pacific the campaign was, from the outset, a true offensive leveled without dissembling at the home islands of Japan. The terrain was entirely different: a series of tiny, isolated, completely and densely fortified atolls or small islands garrisoned tor maximum strength. In the attack of such redoubts there could be no tactical surprise, no razzle-dazzle of deception. The entire problem was well understood far in advance, both by the attacker and by the enemy.
Nevertheless, despite every superficial difference between the two campaigns, the battle mission of the Fleet Marine Force, wherever it fought, was to further the naval campaign) and the interdependence of the Fleet afloat and the FMF ashore characterized Pacific Fleet operations throughout the war.
With this preamble, therefore, let us consider the South Pacific.
Guadalcanal typified not only the South Pacific theater and campaign, but it dramatized to the American public the true meaning and function of their Fleet Marine Force.
In early 1942 it was apparent to the strategic planners in Washington that an operation in Melanesia was required. Guadalcanal-Tulagi suggested itself as a target because of the magnificent harbor at Tulagi and the presence of airbase sites on Guadalcanal. In addition early seizure of Guadalcanal would afford a counterpush for the rapidly-developing enemy strength in that area, presumably being massed for further southward attacks toward the New Hebrides and ultimately the Australia-United States lifeline.
Obviously the operation would have to be amphibious, and obviously it was incident to the Naval campaign. Despite prophecies of disaster and recommendations that the assault be delayed (both arising outside the Naval service), the 1st Marine Division, FMF, with little more than a month's warning was committed to the operation by the Chief of Naval Operations, Admiral King.
Although the margin was in some senses never closer during the whole Pacific war, by the time Army units were available in strength to back up the Fleet Marine Force some four months after initial landings in August, 1942, Guadalcanal, recognized as a turning-point by the Japanese and by the American-British coalition in that theater alike, was firmly secured for our use.
To thoughtful students of naval war the prime lesson of Guadalcanal was that, without the Fleet Marine Force, the operation could never have happened. Undertaken as a purely Naval venture by Fleet units and Marines, Guadalcanal, the United Nations' first major offensive, demonstrated the dependence of sea power upon Fleet expeditionary troops, as well as the degree to which such troops had been prepared and held in readiness by the FMF.
At this point it might be well to emphasize:
The two dominant attributes of a Fleet expeditionary force are its high readiness for employment and its mastery of amphibious techniques. Each is the product of long and specialized training.
Guadalcanal and the subsequent operations of the South Pacific campaign epitomized the former concept, that of readiness. It was Fleet Marine Force readiness which made Guadalcanal possible; which enabled an FMF holding force to secure the New Hebrides in March, 1942; and which permitted the offensive to be assumed by August of the same year.
If the battles of the South Pacific proved that the Fleet Marine Force was ready for war, those of the Central Pacific demonstrated its grasp and virtuosity in amphibious assault. Except for Okinawa—which was really not a part of either the South or Central Pacific campaigns—the entire roll of Central Pacific battles, from Tarawa to Iwo Jima, was by necessity a series of seaborne frontal assaults against positions fortified and organized with every refinement that Japanese laboriousness and ingenuity could provide. To reduce such strongholds was truly amphibious warfare a l'outrance—the assaults which the Marine Corps had foreseen and planned for during the decades of peace.
Rather than attempt any survey of all the successive operations between Tarawa, with which the Central Pacific amphibious campaign truly began, and Iwo Jima, which just preceded Okinawa, it would be most enlightening not only to see how these two amphibious assaults of unsurpassable toughness were executed, but also to note what improvements in basic technique the Fleet Marine Force had made during the two years of Central Pacific fighting which elapsed between Tarawa and Iwo.
Tarawa and Iwo Jima had many factors in common. Each was a small objective, densely organized into a single major defensive system; each, in its approaches and terrain, precluded any appreciable degree of tactical surprise; each was correctly estimated in advance to represent a job of the most difficult and desperate character.
In only two really major respects did Tarawa and Iwo differ. The first aspect was sheer size. Tarawa was defended by 4,836 Japanese, whereas Iwo's garrison exceeded 22,000, all but about 500 of whom had to be killed. More important than the difference in scale between the two assaults, however, was an intangible—experience. Before Tarawa, although the Fleet Marine Force possessed elite troops and ample doctrinal bases for successful execution of a frontal amphibious assault against opposition, this fact nevertheless remained theoretical. Less than two years later, the FMF had come through not only Tarawa but the Marshalls, the Marianas, and Peleliu, all bitterly-contested assaults which in some sense prepared the Marine Corps for Iwo Jima, its most harrowing single struggle.
Perhaps the best way to visualize the progressive development of amphibious assault technique and doctrine which took place between Tarawa and Iwo would be to consider with regard to each operation the major component matters which compose the ingredients of a successful landing against opposition.
Preliminary preparation of the objective was achieved in each case solely by naval bombardment and preliminary air attacks (carrier and shore-based). Considering only the nature of the objective, each preliminary preparation was to some extent inadequate, but the contrast in method of preliminary bombardment was startling. Equally remarkable and certainly indicative of professional virtuosity gained from experience were the highly accurate forecasts by Fleet Marine Force planners as to the extent of preliminary bombardment which would be required for any sort of overall preparation of Iwo Jima. An unassailable case was made out that the little island would need at least ten days' naval gunfire preparation, and although high strategic considerations arbitrarily reduced the actual duration of preliminary bombardment to three days, the outcome confirmed everything that had been postulated by the Marine naval gunfire planners for Iwo. The method of Tarawa's preliminary bombardment was that of "saturating" the island by target-areas in expectation that this would reduce all targets of importance. Iwo Jima's method was a precise and methodical reduction, installation by installation, in order of well-determined priorities, of known and tabulated targets—a technique which the experience of Tarawa had proven essential and which the bombardments of the Marshalls (and Guam especially) had proven feasible.
Fires in close support of the landing. At Tarawa, due to insufficient familiarity with the capabilities of the weapons and to loose aviation timing, naval gunfire and aviation fires in support of the landing were lifted too far in advance. At Iwo Jima, the landing was closely preceded by one of the most heavy and closely-positioned rolling barrages of naval gunfire in the history of amphibious warfare.
Logistic support of the landing. One of the major bottlenecks of the Tarawa operation was that of logistic support. Due to enemy resistance and to the non-existence of some elements of now-accepted shore party doctrine, the trickle' of supply onto Betio's beaches was pitiful. On Iwo Jima troops were well fed, reasonably well supplied, and mail was received several times during the month of battle itself.
Landing craft. The quantity and characteristics of the landing craft available in 1943 for Tarawa were by no means optimum, despite the fact that they represented the best available. Perhaps the most notable fact in this connection is that certain Navy officers wanted to push the landing in with LCVP's whereas the Marine planners insisted that only LVT's (amphibian tractors) were suitable to cross the reefs. At Iwo Jima, there was a sufficiency of the correct type of landing craft.
Landing Force Communications. Development of better material and the impetus of individual combat experience had evolved more suitable radio equipment and generally more complex organization of communication nets, channels, and systems. At Tarawa much trouble was encountered from immersion of radio equipment; at Iwo Jima this factor was greatly minimized.
Assault technique and tactics. At Iwo Jima and at Tarawa, the fighting ability of the individual Marine came into sharp and bitter focus. On each occasion the battle was one of frontal assault and very close combat against fortified positions. Before Tarawa, although such amphibious assaults had been projected in theory, one had never been executed. Tarawa demonstrated that the doctrines were sound. At Iwo Jima the troops could reap the benefit of Tarawa's experience in the form not of a theory, but of tested combat-experience. Without Tarawa, the even greater assault of Iwo would not have been possible. For that matter, however, without the years of study, experiment, and development at Quantico, neither Tarawa nor Iwo could have been carried through to success.
By the end of the war, the Fleet Marine Force was poised for invasion of the Japanese homeland. As a result, both the III and V Amphibious Corps were utilized for occupation of conquered or liberated territories in Japan and China. Concurrently, as the situation permitted, their orderly demobilization was carried out, unmarred by indiscipline or untoward incident.
During the past two years, in addition to occupation missions carried on by the Marine Corps, the shaping of the postwar Fleet Marine Force has progressed.
In keeping with the now established U. S. naval concept that every major fleet requires its expeditionary force of Marines, the FMF as such now consists of two major forces: Fleet Marine Force Pacific ("FMFPac") and Fleet Marine Force Atlantic ("FMFLant"), for service respectively as components of the Pacific and Atlantic Fleets.
Each of these Fleet Marine Forces embodies at least one Marine division, supporting logistic elements, and Marine aviation units for close air support. At the present, certain changes in organization are under consideration with the objective of shaping the ultimate organization of Marine Corps tactical formations to meet the prospective demands of ultra-modern war so that, regardless of changes in technique or weapons, the FMF may be able to carry out its basic functions, which of course are simply stated and remain unchanged.
One possibility along these lines, however, remains relatively unexplored. This is the thought, often informally expressed, that the readiness and mobility of the Fleet Marine Force would lend itself excellently to its employment as the United States component of United Nations security forces. Since, in the past, Marines have carried out a traditional function, in effect, as "State Department troops"—that is, as expeditionary forces for the projection of U. S. foreign policy abroad in times of peace—it would appear entirely logical that they should carry on this role within the framework of the U.N.
Regardless, however, of the turn of events, the Marine Corps will continue its studies and will continue to strive for quality, elan, and esprit. Now firmly embodied in the structure of U. S. sea power, the Fleet Marine Forces will remain in readiness so that the amphibious spearhead of the Fleet may never be blunted.
Entering the Marine Corps from Yale University and the NROTC, Major Heinl served in South America and the Caribbean, fought at Pearl Harbor on December 7, 1941, and served in the South and Central Pacific campaigns, including Iwo Jima and the occupation of Japan. He was successively naval gunfire officer of the 3d Marine Division, V Amphibious Corps, and finally of the Fleet Marine Force, Pacific. He is now on duty at Marine Corps Headquarters, Washington, D. C.
1 The official definition of the term "Fleet Marine Force" is as follows:
"A fleet marine force is defined as a balanced force of land, air, and service elements of the U. S. Marine Corps which is integral with the United States Pacific and/or Atlantic Fleet. It has the status of a full type-command and is organized, trained, and equipped for the seizure or defense of advance naval bases and for the conduct of limited amphibious or land operations essential to the prosecution of a naval campaign."—Navy Department General Order 245, para. 10(a) (4), dated November 27, 1946.
2 Guantanamo Bay, one of the great natural harbors of the Caribbean, lies in southeastern Cuba, some 40 miles east of Santiago, where Admiral Cervera's fleet was based. Despite its great strategic importance, the Bay was defended only by one fort and a Spanish field force; and its seizure was accomplished by the Marine battalion after a week's operation during which Sergeant John Quick won the Medal of Honor for calling in and controlling ships' gunfire support by semaphore while under intense Spanish rifle fire.
3 For a detailed narrative of the Iceland operation, see The 1st Marine Brigade (Provisional), Iceland, 1941-1942, by John Zimmerman, Historical Division, U.S. Marine Corps Headquarters.
4 In the Pacific, where this form of support was more extensively used than elsewhere, some 129,000 tons of naval gunfire was delivered against shore targets incident to support of Fleet Marine Force operations.
5 The defense battalion was really a virtual regiment embodying in capsulized form the minimum elements required for the antiaircraft and surface defense of an advanced base. Its mission was to retain high strategic mobility for rapid movement by sea and equally rapid defensive development and organization of advanced bases. The unit contained antiaircraft guns, seacoast defense guns of medium calibre, machine-guns for beach-defense and light AA missions, and enough service and logistic elements to maintain the battalion independently. Its strength was approximately 1,000, and a prime example of its utility was the heroic defense of Wake by elements of the 1st Defense Battalion, FMF, (less than half of which was present during the siege).