Chapter 6: Finish in the Marianas
By any rational standard, the most devastating cost of war is the lives of the men it kills and maims. In these terms, the price of Guam came high. In 21 days of battle Marine units of the Southern Troops and Landing Force lost 1,190 men killed and 377 died of wounds and suffered 5,308 wounded in action; the 77th Infantry Division casualties were 177 men killed and 662 wounded.1 In the same period, 10,971 Japanese bodies were counted.2 Sealed in caves and bunkers by shellfire and demolitions lay hundreds more of the enemy dead.
Perhaps as many as 10,000 Japanese were still alive in the jungles of Guam on 10 August. Except for the doomed group defending the enemy headquarters at Mt. Mataguac, there was little cohesion among the men that survived. In the months to come, when American troops in training for combat sharpened their skills in a perpetual mopping-up action, all Japanese efforts at counterattacks and guerrilla warfare floundered in a bitter struggle for survival. Starvation was a constant specter to the men hidden in the vast stretches of jungle, and many of those that were later captured or killed were too weak to fight or hide any longer. For these survivors of the Thirty-first Army, Guam became a nightmare.
Change of Command3
On 8 August, Admiral Nimitz informed Admiral Spruance of the future plans for the troops and commanders involved in the fighting on Guam. General Geiger and his staff were needed as soon as the campaign was ended to take charge of the landing force preparations for the operations pending against the Palau Islands. General Holland Smith was to be relieved as Commanding General, Expeditionary Troops and returned to Pearl Harbor to assume his duties as Commanding General, Fleet Marine Force, Pacific. General Schmidt and his VAC headquarters were to assume command of all assault troops remaining in the Marianas. In discharging this responsibility, Schmidt was to report to Admiral Spruance and later when directed, to the Commander, Forward Area, Central Pacific, Vice Admiral John H. Hoover.
For the time being, the assault troops of IIIAC were to remain on Guam, but the 1st Provisional Marine Brigade was to depart soon for Guadalcanal, where it would join the 29th Marines and other reinforcing units to become the 6th Marine Division. Corps troops were scheduled to load out for training and staging areas in the South Pacific as shipping became available. The 77th Infantry Division, now blooded in combat and veteran in outlook, was to reorganize and refit as quickly as possible at Guam and prepare for early employment in another operation. Only the 3rd Marine Division was due to remain for an extended period on the island it helped capture, but this unit, too, would be in battle again before seven months went by.
At 1030 on 10 August, shortly after the 2nd Battalion, 3rd Marines had accounted for the Japanese armor near Tarague, the Indianapolis arrived at Guam and dropped anchor in Apra Harbor. In the afternoon at 1635, Admiral Nimitz and his party, including the Commandant of the Marine Corps, Lieutenant General Alexander A. Vandegrift, landed at Orote airfield and immediately boarded the Fifth Fleet flagship for the first of a series of conferences among senior officers concerning future operations in the Pacific. On the 11th, Nimitz and Vandegrift inspected combat troops and supply installations, and before returning to Pearl, conferred with General Larsen regarding base development plans for the island.
Most of the ships that had taken part in FORAGER had already departed by the time Guam was declared secure. At noon on the 10th, Admiral Conolly turned over his responsibilities as CTF 53 and Senior Officer Present Afloat (SOPA) to Admiral Reifsnider. Conolly then flew to Pearl Harbor with key staff members to begin again the intricate task of planning an amphibious operation. Ten days later, Reifsnider in turn relinquished SOPA duties to a deputy of Admiral Hoover and sailed in the George Clymer for Hawaii. On his departure, Task Force 53 was dissolved.
General Geiger and his staff flew to Guadalcanal early on 12 August, turning temporary command of STLF over to General Turnage. On the same day, General Schmidt, at sea en route to Guam, reported by dispatch to assume command of all assault troops on the island. The VAC CP opened near Agana at 1430 on the 13th.
On 15 August, Admiral Nimitz’ defense and development plan for the Central Pacific became effective at Guam. Admiral Turner’s Joint Expeditionary Force was dissolved, and Admiral Hoover was assigned responsibility for operations at Guam as he had been for Saipan and Tinian on the 12th. On the 15th, as part of the changeover, General Larsen assumed his duties as island commander.
One more step remained to be taken before the campaign for the capture of the southern Marianas became a matter of history. On 26 August, Admiral Spruance was relieved of responsibility for the Forward Area, Central Pacific and all forces under his command by Admiral William F. Halsey. For a time, Halsey’s Third Fleet, using most of the ships and many of the men that had fought under Spruance, would carry on fleet operations against Japan.
As Halsey characterized the change: “Instead of using the stagecoach system of keeping the drivers and changing the horses, we changed the drivers and kept the horses. It was hard on the horses, but it was effective.”4 Spruance and his veteran staff and senior commanders would resume direction of the planning and preparations for the major amphibious campaigns aimed at the inner circle of Japanese defenses.
Island Command Activities5
As the assault phase on Guam drew to a close, General Larsen assumed increasing responsibility for operations on the island. On 2 August, control of Orote Peninsula and Cabras Island passed to Island Command, and on the 7th, Larsen took over the operation of all extended radio circuits and a joint communications center. Supervision of all unloading activities was assigned to Island Command on 9 August. As garrison shipping arrived, the number and complexity of troops reporting to the island commander increased steadily.
General Larsen’s initial task organization for base development included an advance naval base force, Lion 6, which was hard at work developing Apra Harbor as the center of a vast naval operating base. Airfield and road construction and stevedoring duties were the principal assignments of elements of the 5th Naval Construction Brigade, which included 12 Seabee battalions and 1 Marine and 4 Army battalions of aviation engineers. Supply activities were concentrated in the dumps and salvage and repair facilities developed and manned by the 5th Field Depot. For air defense, Larsen had MAG-21 and four antiaircraft battalions. V Amphibious Corps assigned him the 3rd Marine Division for ground defense.
To this myriad of responsibilities for building Guam into a major staging, supply, and training base for future Pacific operations, General Larsen added the mantle of de facto governor of the Guamanians. The civil affairs section of Island Command had approximately 21,000 men, women, and children to care for, and to start back on the road to self-sufficiency. The cultivation of native gardens and the revival of native industries were actively fostered, and hundreds of men and women were employed as laborers and clerical workers in the burgeoning port, airfield, and supply facilities.
To protect and supervise the Guamanians, Admiral Nimitz authorized the formation of an island police, successor to the prewar Insular Patrol Force. Formed from a nucleus of former members plus military policemen from Island Command, all under a Marine officer, the new Local Security Patrol Force performed normal civilian police functions. In addition, however, these men, and many other Guamanians who volunteered as guides to American patrols, took an active part in hunting the Japanese. Isolated native villages and
farms were particularly vulnerable to foraging raids by the harried enemy troops, who were trying to keep alive in the jungle.
Soon after assuming responsibility for the assault troops on Guam, General Schmidt directed that the 3rd and 77th Divisions each maintain an infantry regiment and an artillery battalion in the northern part of the island with a mission of killing or capturing the remaining Japanese. The 21st Marines and the 306th Infantry, which drew the initial patrol assignments, accounted for an average of 80 enemy a day between them in the last two weeks of August. On the 22nd, the 3rd Division passed to Island Command control for garrison duty and took over sole responsibility for the conduct of mopping-up operations; the 306th Infantry was relieved on 26 August to return to the 77th Division base camp.
While the patrol operations continued without letup, the majority of the assault troops under VAC command either shipped out from the island or settled into a rehabilitation and training routine with the emphasis on readying the men for early employment in combat again. The III Corps Headquarters and Service Battalion and the Signal Battalion left for Guadalcanal on 15 August. On the 21st, elements of the 1st Brigade began loading ship, and the veteran troops destined to form the new 6th Division sailed for the South Pacific on the 31st. In areas assigned by Island Command, the 3rd Marine Division established its unit camps along the east coast road between Pago Bay and Ylig Bay, and the 77th Division encamped in the hills above Agat along Harmon Road.
The preparations of the 3rd and 77th Divisions for further combat highlighted the role that Guam was to play during the remainder of the war. In addition to its development as a major troop training area, the island was transformed into a vast supply depot and a major naval base, and was eventually the site of Admiral Nimitz’ advance fleet headquarters. On the plateau of northern Guam, where the final pitched battles had been fought, two huge airfields and a sprawling air depot were wrested from the jungle to house and service B-29s of the Twentieth Air Force, which struck repeatedly at Japan. A little over a year after the date that General Geiger had declared the island secure, it housed 201,718 American troops: 65,095 Army and Army Air Forces; 77,911 Navy; and 58,712 Marine Corps. Reunited on Guam for operations against the Japanese home islands were the 3rd and 6th Marine Divisions, the former returned from the fighting on Iwo Jima and the latter from the battle for Okinawa.
During the period when the American forces on Guam were settling into a bustling routine of preparation for future operations, the situation of the Japanese hold-outs steadily deteriorated. Many of the men that hid out in the jungle were weaponless, few of those that were armed had much ammunition, and virtually none that had the means to fight showed any disposition to engage the Marine patrols. The overwhelming obsession of the enemy troops was food, and starvation forced many of them to risk their lives in attempts to steal rations. Gradually, as the months wore on, two
officers among the survivors, Lieutenant Colonel Takeda and Major Sato, were able to establish a semblance of organization, but for the most part, the Japanese that lived did so as individuals and small groups, fending for themselves and avoiding all contact with the Americans.
In the latter stages of the war, psychological warfare teams of Island Command were increasingly successful in overcoming the Japanese reluctance to surrender. On 11 June 1945, Major Sato, convinced of the futility of holding out any longer, turned himself in and brought with him 34 men. By the end of August, records showed that 18,377 dead had been counted since W-Day and that 1,250 men had surrendered. After the Emperor had ordered all his troops to lay down their arms, the Americans were successful in convincing Lieutenant Colonel Takeda that he should come in. On 4 September, Takeda marched out of the jungle near Tarague, bringing with him 67 men. A week later he was able to persuade another group of 46 men to surrender, the last unified element of the garrison that had defended Guam. Individual Japanese continued to hide out in the jungle for years after the war was over, despite repeated efforts to convince them that Japan had surrendered.
Lessons of Guam6
The operations leading to the recapture of Guam, as an integral part of the overall Marianas campaign, suffered and profited as did those at Saipan and Tinian from the state of progress in amphibious warfare when FORAGER was launched. In one respect, the extent of the prelanding naval bombardment, a standard was set that was never again reached during the war. In the Palaus and the Philippines, at Iwo Jima and Okinawa, gunfire support ships never again had the opportunity for prolonged, systematic fire that Admiral Conolly exploited so successfully.7 The destruction of Japanese positions led the IIIAC naval gunfire officer to observe:–
The extended period for bombardment plus a system for keeping target damage reports accounted for practically every known Japanese gun that could seriously endanger our landings. When the morning of the landing arrived, it was known that the assault troops would meet little resistance [from enemy artillery or naval guns.]8
Although a few coast defense artillery pieces and antiboat guns did manage to weather this shelling and the accompanying carrier air strikes, most were knocked out as soon as they revealed themselves. The devastation wrought among the 1st Brigade assault waves by one undetected 75-mm gun at Gaan Point illustrated the probable
result of a less comprehensive target destruction plan. Where the enemy guns had not been destroyed, as was the case with a pair of 6-inch naval guns in the 3rd Division landing zone, the murderous effect of area neutralization fires prompted crews to abandon their exposed emplacements.
The 1st Brigade, in its comments on naval gunfire, summed up the case for the assault troops—the more preparation, the better. General Shepherd recommended:–
... in future operations the amount of naval gunfire placed on a well-defended beach upon which troops are to be landed be no less than that fired in the Agat area of Guam. If possible, a greater amount of ammunition should be fired. The same amount of ammunition fired over a longer period of time seems to be more effective than that amount fired in a short period.9
Once the III Corps had landed, the use of naval fire support was continuous and generally effective. In particular, every assault unit was high in praise of the system of providing frontline battalions a ship to fire and illuminate throughout the night. Star shells were as popular with American combat troops as they were hated by the Japanese. Marine ground commanders were impressed with the need for a greater supply of illumination ammunition; General Turnage asked that “more stars be made available for future operation,”10 and General Shepherd stated that it would be necessary to have “at least ten times the number of star shells in a future operation covering the same period of time as was allowed for the Guam operation.”11
Carrier aircraft were equal partners with gunfire support ships in the prelanding bombardment; they shared with land-based planes flying from Saipan the deep support missions delivered for the troops once ashore. During the operation, IIIAC noted that at least 6,432 sorties were flown, with 3,316 strafing runs made and 2,410 tons of bombs dropped. The scout, torpedo, and fighter bombers were most effective against targets that could not be reached by the flat trajectory fire of naval guns, such as the defiladed areas of Fonte Plateau from which Japanese artillery and mortars fired on the beaches and where enemy troops assembled for counterattacks. When the target area was close to the front line, opinions on the effectiveness of air support were varied and frequently critical. Admiral Turner characterized close air support at Guam as “not very good.”12
General Shepherd noted that because most vehicular radios, the only ones capable of operating on the Support Air Direction (SAD) net, were damaged by salt water, the brigade air liaison parties directed relatively few air strikes. Those that did take place were kept beyond a bomb safety line, 1,000 yards from the Marine front lines, because of “rather severe casualties to our troops from bombing by our supporting
aircraft.”13 The 77th Division had only one air strike directed by its air liaison parties, but the 3rd Division made frequent use of ground-controlled strikes within 500 yards or less of its assault troops. On four occasions division troops were the target of misdirected bombing and strafing, and General Turnage recommended more accurate briefing of pilots to prevent repetition of such incidents.
The most crucial area of air support operations was communications. The SAD net was crowded at all times, and General Turnage observed that very few close support strikes were carried out on time or within limits set by requesting agencies. The method of operation worked out by Commander, Support Aircraft of TF 53 called for all requests from battalion air liaison to clear through regiments. He also frequently checked with divisions “since frontline reports from battalions were not sufficient to establish the whole front line near the target area.”14 Once the air liaison officer had shifted to the SAD frequency, he adjusted the dummy runs made by the flight leader or air coordinator until the plane was on target. Then a single bomb was dropped and if it was accurate, the entire flight would follow and attack. The time consumed in request, processing, approval, and final execution was generally 45 minutes to an hour or more. Although the Commander, Support Aircraft considered the time spent justified by the success of the missions, ground units generally asked for more immediate control of planes by air liaison officers and for a method of operations and system of communications that would ensure a faster response to the needs of assault troops. In this conclusion, that air liaison parties should have more direct contact with supporting planes, the infantrymen got firm backing from the Commander, Support Aircraft, Pacific Fleet, in his comments on air operations in the Marianas.15 He also pointed out there was a need for greater understanding “on the one hand by the Ground Forces of the capabilities and limitations of aircraft, and on the other hand by the pilots of what they are supposed to accomplish.”16 There was undoubtedly generous room for improvement in air support techniques, and this need was sorely felt, because when planes were properly used they proved themselves invaluable in close support.
To General Geiger and many other Marines, a partial solution to air support problems lay in increased use of Marine aviation. The IIIAC air officer pointed out that Marine bombing squadrons had clearly demonstrated their capability in providing close (100 to 500 yards) support to ground troops (notably at Bougainville while working with the 3rd Marine Division). He commented “that troop commanders, whether justifiably so or not, have repeatedly expressed a desire that Marine Bombing Squadrons be used for close support of their troops.”17 In reinforcing this finding with a recommendation
that specially trained Marine air support groups be placed on CVEs, the Expeditionary Troops air officer concluded:–
The troop experience of senior Marine pilots combined with the indoctrination of new pilots in infantry tactics should insure greater cooperation and coordination between air and ground units.18
In assessing the operations of another supporting weapon, armor working directly with the infantry, both the 3rd Division and the 1st Brigade were unanimous in praising the medium tank as the most effective weapon for destroying enemy emplacements. Point-blank fire by the 75-mm guns collapsed embrasures, cave defenses, and bunkers even after enemy fire drove supporting infantry to cover. The 3rd Tank Battalion, which employed flamethrower tanks for the first time, was well satisfied with the new weapon, but found that attempts to mount infantry flamethrowers on tanks were generally unsatisfactory. The 3rd Division recommended that in the future one tank of each platoon be equipped to spew flame. Although the brigade had no flame tanks, it did successfully employ borrowed Army tank destroyers armed with a 3-inch gun which showed great penetrating power in attacking cave positions. Operations in northern Guam demonstrated that armor and dozer blades were an effective combination against the jungle. The Marines frequently employed tanks working in conjunction with bulldozers in breaking trails; the 77th Division found that a dozer with an armored cab was the most effective vehicle for penetrating the heavy brush.
In general, infantry weapons proved reliable despite the weather and prolonged rough usage in the clutching jungle, but flamethrowers were easily damaged, with the firing mechanism a particularly sore spot. General Shepherd recommended that sufficient replacement flamethrowers be carried to the target to maintain initial allowances.
During the Guam operation, 3rd Division and 1st Brigade experiments with the use of war dogs produced varied results. The dogs proved effective on night security watch and generally reliable on patrol, although they failed to alert Marines to hidden enemy troops on several occasions. Little need was found for the messenger dogs, for the SCR-300 radio provided reliable communications for isolated units. Patrols of the 3rd Division found a new use for the dogs, though—investigating caves for hidden enemy before Marines entered; this technique proved best suited to the more vicious and aggressive animals.
Marine infantry battalions on Guam operated under a new table of organization, one that included in each rifle company the machine guns and mortars that had formerly been part of separate battalion weapons companies. The change worked well, gave closer support to the riflemen when needed, provided both company and battalion commanders with better control of supporting weapons, and simplified frontline supply channels. Since machine guns were prime targets for enemy fire, casualties among the crews were heavy, but replacements were found more
easily among rifle company personnel. The other important change in infantry organization, the 13-man rifle squad with its three 4-man fire teams, proved to be a harder-hitting and more flexible fighting unit than its 11-man predecessor.
Brigade and division artillery, closely trained with the troops they supported, were an integral part of a tank-infantry-artillery team. Most ground commanders echoed General Shepherd’s comment that “artillery was the most effective weapon employed during the operation.”19 Firing batteries quickly landed, promptly registered, and thundered into action early on W-Day. Whenever the front lines advanced appreciably, the artillery followed. The 12th Marines displaced five times between 1-10 August, the 77th Division artillery battalions made four moves to remain in direct support, and in northern Guam, one of the 75-mm battalions of the brigade moved forward five times and the other four. In all displacements, artillery units were handicapped by the 50 percent reduction in motor transport imposed by reduced shipping space; vehicles were frequently pooled to effect rapid movement and keep the howitzers within supporting distance.
In the initial stages of the assault, the DUKW proved invaluable to the artillery units.20 Not only did the amphibian trucks keep an adequate supply of ammunition close to the firing batteries, they also provided a satisfactory means of getting the 105-mm howitzers ashore early in the fighting. Prior to the FORAGER Operation, the lack of a suitable vehicle to land the 105s in the assault had prompted the retention of the lighter and more maneuverable 75-mm in the Marine artillery regiment. Colonel John B. Wilson, commanding the 12th Marines, now recommended that the remaining 75-mm pack howitzer units be replaced by 105-mm battalions. This exchange would give the division more firepower and simplify ammunition handling and supply.
The key to effective fire support was rapid and efficient communications between forward observers and fire direction centers. Radios were used when necessary, but wire was employed to carry most of the traffic. The 12th Marines found the use of a forward switching central to be “extremely advantageous.”21 Artillery liaison party wire teams were required to maintain lines back only to a switching central in the vicinity of an infantry regimental CP; from there artillery battalion wiremen took care of the trunks to the fire direction center (FDC).
Centralized fire coordination was a feature of the Guam operation. The
corps air and naval gunfire officers worked closely with the Corps Artillery FDC. Once his CP was functioning ashore, the Corps Artillery commander, General del Valle, was assigned operational control of all artillery on the island. This system enabled him to mass fires quickly and assign reinforcing missions as the situation required. In addition, he was able, in the light of the overall campaign picture, to make effective assignment of ammunition priorities, transportation, and firing positions.
General del Valle was not satisfied with the procedures used to get his own corps units ashore. He reported that his battalions were “prevented from entering the action ashore at an early stage with sufficient ammunition and suitable communications to render the desired support to the attack of the Corps during its critical stages.”22 In particular, he noted that the unloading was out of his control and at variance with the planned scheme of unloading and entry into action. He wrote that “as long as this control is vested in other officers, not especially concerned with, nor interested in, the operations of Corps [Artillery] satisfactory results will not be achieved.”23
Ammunition supply was a particularly pressing problem in the first days of the operation when the heavy 155-mm shells and powder began to come ashore in large quantities. Shore parties were hard put to handle the multiple transfers from boat to amphibian, vehicle to truck, and truck to dump. Large working parties of artillerymen were needed to handle their own ammunition on the beaches and in dumps ashore. The general recommended that an ammunition company and a DUKW company be assigned to Corps Artillery in the future to move ammunition directly from ship to battalion and battery dumps ashore.
Since no Japanese aircraft visited the air space over Guam, the antiaircraft batteries of Corps Artillery were not used in their primary function. The versatility of the guns and the destruction wrought by their firepower was clearly demonstrated, however, by their frequent use in support of ground troops. General del Valle drew particular attention to the employment of the 9th Defense Battalion in perimeter defense and in the patrolling in southern Guam as an illustration of the range of usefulness of antiaircraft units.
Many problems in landing troops and supplies at Guam were anticipated; others, as they occurred, were solved by combat team, brigade, division, and Corps Service Group shore parties. The effort to keep the assault troops supplied adequately required thousands of men, a force greater in strength than the 1st Brigade. The 3rd Division had ship unloading details of approximately 1,200 men and shore working parties that numbered 3,300; the 1st Brigade left 1,070 men on board ship and used 1,800 on beach and reef; and the 77th Division, employing three battalions of shore party engineers plus some 270 garrison troops with low landing priorities, had 583 soldiers unloading ships and 1,828 working ashore. Almost one-fifth of the total strength of IIIAC
was engaged in the initial shore party effort.24
In allotting troops for the shore parties, General Geiger assigned the brigade assault forces a replacement unit. This organization, the 1st Provisional Replacement Company (11 officers, 383 enlisted men) was employed as shore party labor when the need was greatest. After the first flood of supplies was manhandled ashore, a fast-paced but orderly routine was established to unload assault and resupply shipping. The manpower requirements of the shore parties lessened, and the replacements were then fed into combat units as required. This use of replacements proved a sound concept, for it cut demands on assault troops for shore party labor and provided a ready source of trained men to fill the gaps caused by casualties. In later Marine operations in the Pacific, replacement battalions moved to the target with the assault echelon for use both as part of the shore party and as fillers in combat units.
Once the round-the-clock labor of the first 48 hours of unloading ended, the major portion of the task of handling supplies from ship to beach dumps fell to the specialists, the Army shore party engineers and the Marine pioneers. The Marine units proved adept at improvisation and in making-do with what they had plus what they could borrow, but they needed more heavy equipment. Corps reported that the pioneers:
... are grossly ill-equipped when there are any beach difficulties or obstacles to overcome. The organizations attached to Corps for this operation had insufficient equipment for reef transfer of cargo, clearing beaches, and building access roads thereto. Even though an additional 25 Trackson cranes were provided, these were insufficient for reef transfer, beach, and dumps. A large number of lifts were beyond the capacity of any cranes belonging to the organizations mentioned. Some organizations totally lacked lighting equipment, others had antiquated equipment with run-down batteries which could not be used when beach operations were put on a 24-hour basis. Fortunately, Army Shore Party Battalions had sufficient equipment to meet minimum requirements for all Corps beaches.25
A good part of the construction work that was necessary to maintain and improve the beach areas and dumps fell to the Seabees, who operated as part of the shore parties in both beachheads. Division and brigade engineers were primarily concerned with direct support of the combat teams. Road and trail construction in forward areas, mine clearance, demolitions of obstacles and enemy defenses, and the operation of water points were all part of combat engineering tasks.
One responsibility shared by Seabees, engineers, and pioneers was the maintenance of an adequate network of roads. Under the impact of heavy traffic, the existing roads disintegrated. There was a constant struggle to repair the main arteries and to build new roads required by combat operations. The restriction on cargo space had hit the engineer units as hard as any
organizations on the island, for much needed equipment had been left behind in the Solomon and Hawaiian Islands. Even when Corps Artillery prime movers equipped with angle dozer blades were borrowed, there were insufficient bulldozers and road-graders to handle the tremendous road-building task. Frequent rains complicated all road operations, for mud prevented coral surfacing from binding and drainage problems caused an epidemic of floods.
Provident but temporary help was provided in this situation by the garrison force Seabee and engineer battalions, whose main mission was airfield construction. The profusion of difficulties faced by equipment-short assault units prompted the corps engineer to recommend that in future operations:
... a minimum of one engineer battalion with heavy grading equipment (a Naval Construction Battalion, a Marine Separate Engineer Battalion, or an Army Aviation Engineer Battalion) be included in the assault echelon of each Marine or Army division, or fraction thereof, in the assault forces.26
The limitations posed by the lack of good roads and the chronic shortage of transportation hampered supply operations to some extent. Nowhere, however, was the course of combat endangered by this situation. When assault troops started moving north, units attempted to maintain a 5-day level of stocks in forward supply dumps, but there were never enough trucks available to meet this goal. The 5th Field Depot was able to supply all units and build up reserve stocks to 20-day levels in most categories. The necessity of feeding thousands of natives ate into the resupply rations, however, and the depot was never able to attain much more than a 10-day level of reserve food. Considered as a whole, logistics problems were competently handled and “the supply system on Guam worked smoothly and efficiently.”27
One of the most heartening aspects of the operation, as indeed it was of other American assault landings, was the effectiveness of the medical treatment of casualties. If a man was hit, he knew that a Navy corpsman or an Army aidman would be at his side as soon as possible. Whatever the difficulties, evacuation was prompt; in the assault phase, the system of routing casualties from forward aid stations through beach and shore party medical sections to ships offshore brought wounded men on board specially equipped LSTs and APAs within an hour after the first wave landed.28 Once field hospitals were set up ashore, many of the less seriously sick and wounded were treated on the island, but there was a steady flow of casualties via ship to base hospitals. Transports with specially augmented medical staffs and facilities for casualty care evacuated 2,552 men from Guam, and the hospital ships Solace and Bountiful carried 1,632 more.
The risks taken by the corpsmen, aidmen, and doctors in their concern for the wounded were great. The frequent
flurries of activity around aid stations, which were usually located on the natural routes of approach to the front lines, often drew Japanese mortar and artillery fire. Enemy small arms fire often seemed to be centered on the men that were trying to save the lives of assault troop casualties. In the course of the Guam campaign, the 3rd Division had 3 medical officers and 27 corpsmen killed in action and 12 officers and 118 corpsmen wounded; the 1st Brigade had 1 officer and 9 corpsmen killed and 1 officer and 35 corpsmen wounded. The 77th Division lost 10 medical aidmen killed and had 35 wounded in action.
An analysis of the lessons learned by Americans at Guam seems incomplete without the viewpoint of the Japanese on their own operations. A postwar study of their role concludes with the judgment:
... that Japanese troops on Guam took charge of the most extensive front as a division under the absolute command of sea and air by the enemy and checked the enemy from securing beachheads by organized resistance in the coastal area for the longest period, in spite of heavy enemy bombing and shelling for the longest time. In view of this, it is no exaggeration to say that this result was the best in the history of the war.29
A further comment based on this study by a present-day Japanese general, writing in an article authored jointly with a Marine veteran of the Guam operation, points out a principle by which the defense might have been even more effective:
With no attempt to distract from the ability of the Japanese commanders, they were forced by Imperial General Headquarters policy to ‘defeat-the-enemy-on-the-beach,’ and accepted battle on two widely separated, and not mutually supporting, fronts. Their fighting strength was sapped by Col Suenaga’s, and subsequent, counterattacks. These attacks, launched piecemeal, could only be indecisive. If Gen Takashina had defended the vital area of Guam, Apra Harbor, he would have seriously delayed subsequent U. S. operations. By so doing he could have delayed the devastating B-29 raids on his homeland. Instead he located his forces behind the landing areas and thus violated the cardinal rule of island defense—defend the vital area.30
Central Pacific Proving Ground
In a little more than nine months, November 1943 to August 1944, the art and science of amphibious warfare made enormous progress. The knowledge gained had been dearly won by the thousands of Americans killed and the many wounded between D-Day at Tarawa and the end of organized resistance at Guam. Each step of the way revealed weaknesses which required correction and problems which required answers. This crucial period of the war was a time when the officers and men of the Pacific Fleet and the Pacific Ocean Areas discovered—by trial and error—the most effective means of wresting a stubbornly-defended island from enemy hands.
Tarawa was the primer, and from the analytical reports of the commanders there and from their critical
Corsairs of MAG-21 taxi down the airstrip of Orote Peninsula, 10 days after the island was secured. (USMC 92396)
B-29s returning from a strike on Japan approach North Field, which was wrested from the jungle battleground of northern Guam. (USAF 59056AC)
evaluation of what went wrong, of what needed improvement, and of what techniques and equipment proved out in combat, came a tremendous outpouring of lessons learned. The development of the LVT(A) was expedited to provide close-in fire support for assault waves, and the value of the LVT was emphasized and its role expanded in future operations. Deficiencies in naval gunfire and aerial bombardment were pinpointed, and measures were taken to improve the delivery and effectiveness of both prelanding bombardment and fire support once the assault troops were ashore. The shortcomings of communications between ship and shore and air and ground drew particular attention, and the training and equipment of air and naval gunfire liaison teams was improved and intensified.
The performance of the fast carrier task forces in the Gilberts campaign clearly demonstrated that Americans had the power to isolate a target area, protect the amphibious forces, and permit a longer and more thorough softening-up of the objective. The carriers provided the means to keep the enemy off-balance, and with the voracious submarines that ranged the Japanese shipping lanes, choked off reinforcements and defensive supplies. From Tarawa onward, as one Japanese admiral said: “Everywhere, I think, you attacked before the defense was ready. You came more quickly than we expected.”31
The carrier attack on Truk convinced the enemy that its vaunted naval base was vulnerable and therefore useless, and the fact that Truk was of no value to the Japanese meant “that its seizure was abandoned as a U. S. objective.”32 The momentum generated by the drive into the Marshalls at Kwajalein and the quickly planned and executed capture of Eniwetok was rewarding. The time of the attack on the Marianas was advanced by months. The swiftly rising power of Admiral Nimitz’ forces, born as much of experience as of new strength, gave meaning to the principle formulated by the foremost naval historian of the war, Rear Admiral Samuel Eliot Morison, who stated that “the closer that one offensive steps on another’s heels, the greater will be the enemy’s loss and confusion, and the less one’s own.”33
Problems of coordination and control in the ship-to-shore movement and in operations ashore cropped up in the Marshalls as they had in the Gilberts, but the difficulties had less effect and pointed the way to better solutions. Naval gunfire was measurably more effective, artillery was used to good account from offshore islands at most objectives, and prelanding aerial strikes were better briefed and executed. Air support techniques and communications procedures remained a worrisome trouble spot in need of improvement. As the LVT had starred at Tarawa, the DUKW shone at Kwajalein, where its performance marked the growth of a family of amphibious vehicles which eased the problems posed by Pacific reefs.
A floating service squadron based in the Marshalls, which could replenish
and repair fleet units, vastly extended the range and duration of fast carrier operations and justified the decision to expedite the decisive thrust into the Marianas. Amphibious planners, sparked by Admirals Spruance and Turner, merged assault and base development plans into a unified whole which ensured a continued rapid advance to the ultimate objective, Japan. The spring and summer of 1944 saw the flowering of a vital skill, logistics planning, whose incredible complexity met the need to sustain massive assaults and at the same time provided a continuous flow of men, supplies, and equipment for a host of existing and future requirements.
The attack on Saipan and the following operations at Tinian and Guam demonstrated the ability of a Marine headquarters to operate above corps level and to prosecute successfully a variety of land campaigns on objectives larger than the fortress atolls. Admiral Spruance’s plan, like all Fifth Fleet operations plans in amphibious campaigns, provided for action to be taken in case of attack by a major enemy naval force.34 This foresight was in good part responsible for the favorable result of the Battle of the Philippine Sea, which Admiral King noted:–
... crippled Japanese naval aviation for the remainder of the war. Planes could be replaced, pilots could not, and, as was discovered later in the year at the Battle for Leyte Gulf, the Japanese no longer had the trained and seasoned aviators that were necessary for successful operations against our fleet.35
The fact that the attack on Saipan lured the Japanese carriers to defeat might alone be enough to call it the decisive operation of the Central Pacific campaign. The capture of the island, however, meant far more. It toppled the war party government of Premier Tojo in Japan, ensured the success of operations against Tinian and Guam, and secured the prime objective—the very long range bomber fields from which B-29s could ravage Japan.
A new pattern of Japanese defense, made possible by room to maneuver, emerged on Saipan. After beach positions fell, the enemy withdrew fighting to final defenses with the sole aim of making the battle as costly as possible to the Americans. The losses suffered by VAC were heavy but unavoidable against a determined foe. When the turn of Tinian came, every effort was bent towards improving the fire support from air and naval gunfire to limit American casualties. Artillery pounded the smaller island for days, and, under the cover of intensive supporting fires, a masterful shore-to-shore assault hit the Japanese defenses from an unexpected front. The result was a quick ending to a battle that might well have claimed the lives of many more Marines than those that did fall.
Intelligence gained at Saipan of the strength and probable defensive tactics of the 29th Division on Guam was instrumental in lengthening and increasing
the effectiveness of preliminary air and naval gunfire bombardment against the largest of the three Marianas target islands. Contemporary Japanese testimony amply supports the conclusion that this fire severely disrupted defensive preparations. Although the dual landings and subsequent operations in the rugged terrain ashore posed difficult problems of coordination and control, IIIAC units readily adapted their tactics to meet the enemy defense. The seizure of this island gave the Navy a base that by the end of the war was capable of supporting one-third of the Pacific fleet and provided the Army Air Forces additional B-29 bases for the aerial campaign against Japan.
In the Marianas as well as in the Gilberts and Marshalls, one aspect of the operations remained unsatisfactory—air support of ground troops. The complex and crowded communications setup caused multiple problems, inadequate pilot briefing led to inaccuracy, and, most important from the point of view of ground commanders, slow response to strike requests made air a far less effective supporting weapon than it might have been. The recognition of the need for improvement was not confined to the men that were supported, for a veteran Navy bombing squadron commander reported to CinCPac:–
In the Guam and Saipan operations, close support was actually almost nonexistent. Beyond tactical support by bombing before the troops landed, and some strategical bombing of rear areas and communications during the battles, little help was actually given the troops on the front lines. It is believed that the entire system must be changed and streamlined to make possible the real Close Support that we are capable of giving the troops.36
Marine commanders pressed hard for increased use of Marine air in close support. They wanted pilots, planes, and a control system oriented to ground needs and quickly responsive to strike requests. The winds of change were in the air in the summer of 1944 and refinements in close support techniques were coming, Operations later in the year saw planes bombing and strafing closer to frontline positions and evidenced a steady increase in the employment of Marine squadrons in this task as well as in air-to-air operations. Admiral Nimitz, in his comments on operations in the Marianas, noted:–
Four CVE’s have been designated for close (troop) support and will embark Marine aircraft squadrons. It is not anticipated that Marine squadrons will furnish all close air support but they will be used with Marine divisions when the situation permits. In addition a certain number of Marine aviators are being assigned to the various amphibious force flagships to assist in the control of support aircraft.37
At the conclusion of the Marianas campaign, senior commanders were generally satisfied that their forces were experts in the techniques of the amphibious assault and veterans in the flexibility of response it required. The admirals and generals were far from complacent, however, for the operations ahead promised to be even “more demanding, bigger in scope, and perhaps tougher and more costly. In joint operations, despite occasional and human friction, forces of the Army, Navy, and Marine Corps had worked well together and learned from each other. There was a will to win that overrode every disagreement and setback, a pervading spirit of “let’s get on with the job.”
In assessing the performance of the Marines in this period, General Vandegrift, writing as Commandant to his predecessor, General Thomas Holcomb, summarized an inspection trip in the Pacific, pointing out that he had:–
... covered 22,000 miles in eighteen days, saw all the force, corps, and division commanders and practically all the regimental and battalion commanders in the field. I went to Saipan, Tinian, and Guam, getting to Guam just before the show was over. Our people did a superb job on all three of those islands. ...38
That comment could as well apply to every man, of whatever service, that played a part in the success of GALVANIC, FLINTLOCK, CATCHPOLE, and FORAGER. Our people did a superb job.
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