On Luzon, and to a lesser extent in the Southern Philippines, the Japanese proved themselves remarkably adaptable, quick to make the best of an adverse situation, possessed of an excellent feel for terrain, tenacious to the point of fanaticism on the defense, and, contrary to general opinion, sufficiently flexible to change plans and dispositions at a moment’s notice. The tactical flexibility of Yamashita’s plans and maneuvers throughout northern Luzon, considered within the framework of his defensive concepts, is certainly notable. It is, indeed, possible to raise questions concerning the Sixth and Eighth Armies’ flexibility as compared to that of 14th Area Army and, in some instances, to that of Filipino guerrilla forces. The record suggests that in many respects the Japanese and the guerrillas may have adapted themselves more effectively than the Sixth and Eighth Armies to the conditions of ground warfare obtaining throughout most of the Philippine archipelago.
Such a comparison raises questions that do not necessarily concern leadership or command, but rather involve the training and generally ponderous organization of the mechanized forces that the United States put into the field. In previous campaigns throughout the Southwest Pacific Area, American ground forces had proved themselves equal or superior to the Japanese in flexibility and adaptability. In those campaigns, the U.S. armies had employed comparatively light forces to seize island perimeters or to clear small islands. But in the Philippines, and on Luzon especially, American forces were faced with the necessity of seizing and clearing relatively large land masses. In these operations, therefore, the Sixth and Eighth Armies had to bring into play mass and maneuver, and had to apply other concepts and methods, including those entailing logistical operations, that the U.S. Army had developed for waging continental land warfare. The application of these concepts had an inevitable effect upon flexibility. On the other hand, the record of the campaigns for the reconquest of the Philippine archipelago raises the question whether the Sixth and Eighth Armies, confronted with the more obvious requirements of ground operations in the Philippines, may not have moved too far toward the adoption of the methods and concepts of continental ground warfare. It also seems legitimate to suggest that the two armies might have employed these concepts and methods, as well as the power under their control, more resourcefully had their previous experience in the Southwest Pacific Area prepared them for the type of warfare required on the land masses of the Philippines.
For American forces, departures from the norm of combat (if such a thing ever existed) involved the development and employment of field expedients to meet special situations. Noteworthy in this category was extensive and effective employment of antiaircraft artillery—both 90-mm. guns and automatic weapons— against ground targets in the mountainous Kembu, Shimbu, and Shobu strongholds and on northern Negros as well. It should also be noted that a few antiaircraft units that were not needed in their normal role came to serve creditably as Infantry.
Another notable departure from normal operating procedure was the varied use to which the artillery liaison plane was put. This versatile light aircraft served not only as the eyes of the artillery but also was employed in a general intelligence role. It evacuated casualties from remote mountain airstrips and was often even pressed into service for supply drops.
Other field expedients are worthy of mention. LVT’s and Dukws were employed for long, overland supply hauls, a task for which these vehicles were not designed; flanged wheels were mounted on jeeps to haul supplies over the railroads of Luzon until conventional engines could be found and placed in service; Carabaos were used to haul supplies over muddy trails that wheeled or tracked vehicles could not negotiate and over which infantrymen could barely slog carrying rifles; and, finally, Army engineer LCM’s, as well as Navy craft of various types, were employed on the rivers of Mindanao. None of these field expedients originated in the Philippines, nor were some of them original with U.S. forces. However, in the Philippines American combat and service units developed these and other field expedients to such a degree that they became, in effect, part of the Army’s standing operating procedure.
The road to triumph in the Philippines was not, of course, solely the story of the Infantry. The contributions of the air forces, the naval forces, the artillery, other supporting arms, and the service echelons were indispensable.
An evaluation of air support operations is difficult. Generally, long-range bombing attacks, by whatever air element, were executed with dispatch, accuracy, and good effect. The story of close ground support operations presents a different picture. Ground combat units that at one time or another had close support from both U.S. Army and U.S. Marine Corps aviation were virtually unanimous in preferring the latter, at least during the earlier months of the campaigns. Later, when Fifth Air Force units became more experienced in close ground support activity and began to work more closely with the ground combat forces, confidence in the Army’s air arm grew. Nevertheless, the campaign ended with almost all ground units still hoping for an improved, more effective air-ground liaison system insofar as Army air echelons were concerned, and also seeking methods by which to establish a closer, more effective working relationship between the Army’s ground and air units.
Any evaluation of the effectiveness of close air support as opposed to artillery support is difficult. Each type of support had capabilities not possessed by the other, and it was normal practice if both were available to employ whichever could best do the job. The Japanese are not of much help in making a determination. Interrogated after the surrender by a ground forces officer, a Japanese might say that artillery was the more effective; interrogated by an air officer the same Japanese might say that air bombardment was more effective. On the other hand, the Japanese pointed out that aircraft could conduct strikes against positions that artillery bombardment could not reach. Moreover, Allied air superiority in the Philippines severely inhibited Japanese movements, forcing them to undertake marches under cover of darkness or to make long, exhausting detours through woods and forests. The sight of an artillery liaison plane in the sky normally prompted every Japanese for miles around to seek cover.
There can be no denying the effectiveness of artillery in the battle for Manila. Whether the air arm could have done the job more effectively and more rapidly is, of course, and unanswerable question —General MacArthur denied it the chance. One of the major air successes, probably, came in the support provided the 43d Infantry Division during that unit’s drive to capture Ipo Dam. Aerial bombardment and close support certainly contributed in large measure to the success of the 503d Parachute RCT’s risky undertaking at Corregidor, and it is not possible to dismiss the air arm’s contribution without mentioning once again the fact that the 1st Cavalry Division’s exposed left flank was protected during the dash to Manila only by aircraft. Finally, one of the most effective weapons throughout the entire campaign to recapture Luzon and the Southern Philippines was the napalm all air elements dropped.
The campaign produced no insoluble logistical problems, and there were no persistent, critical shortages of supplies of any type. As might be expected, there were many logistical difficulties, beginning with the adverse surf conditions at Lingayen Gulf that upset supply operations during the first week on Luzon and brought to light weaknesses in the planning and execution of the amphibious undertaking. Most of the supply problems the Sixth and Eighth Armies encountered during the campaign, however, grew out of transportation difficulties. These in turn resulted from destruction of rail and highway bridges, lack of railroad rolling stock, problems inherent in moving supplies over the rugged, trackless terrain where much of the fighting took place, the poor condition of many roads, and the fact that limitations on shipping space made it impossible for most units to bring forward all their organic transportation during the early stages of the operation. Field expedients already mentioned solved some of the transportation problems. Other solutions, on Luzon, included the leapfrogging of bridging equipment, and, throughout the islands, the extensive employment of Filipino hand-carrying parties.
A theatre-wide shortage of artillery ammunition (and of some types of mortar ammunition) compelled Sixth Army on Luzon to impose a rather strict rationing system. The rationing, in a larger sense, did not affect the ultimate outcome of the campaign, although some units may have lacked the artillery support they desired for a specific attack. But it must be remembered that it is almost a principle of warfare that no infantry commander ever gets the artillery support he wants or thinks he needs.
Shortages of other types of supplies were invariably temporary and usually stemmed from transportation problems. Whatever their causes, solution of the multitude of major and minor logistical problems involved in a campaign of the magnitude of the Luzon-Southern Philippines operations demanded round the clock work. It is doubtful that the service forces put in longer hours on any American battleground of World War II than they did on Luzon and in the Southern Philippines.
One phenomenon of the reconquest of the Philippines was certainly far different from any other experience of the war in the Pacific. That was the presence of a large, organized guerrilla force backed by a generally loyal population waiting only for the chance to make its contribution to the defeat of Japan. It is debatable whether American headquarters were adequately prepared to make the most effective use of the guerrilla forces that existed on Luzon and in the Southern Philippines; it is also questionable whether American forces made the best possible use of the guerrillas after the campaign began. From GHQ SWPA on down through infantry divisions in the field, the orders and plans concerning the guerrillas, as well as the machinery set up at various echelons to control and supply the guerrillas, indicate that before the invasion of Luzon U.S. forces expected little more of the guerrillas than the acquisition of tactical intelligence and certain types of service support. It appears that in many instances American commanders were reluctant to assign guerrilla units specific combat missions of even the most innocuous sort. Sometimes guerrilla units acquired a combat mission only after they had launched an operation themselves; sometimes, as seems to have been the case with Sixth Army vis-à-vis USAFIP(NL), the combat mission came only after American headquarters realized that they did not have sufficient regular forces to undertake assigned tasks. In any case, it is certain that both the Sixth and the Eighth Army ultimately made more extensive use of guerrillas than was originally contemplated.
It is unfortunately impossible to measure in concrete terms the contribution of guerrilla forces to the outcome of the campaigns. Some units were good; some were not. An occasional guerrilla force, with political aims or under a leader with delusions of grandeur, caused more trouble than it was worth. In the end, however, almost all served in one way or another to the limits of their capabilities. Beyond the shadow of a doubt the guerrillas saved many thousands of American lives.
The story of the Filipino contribution to the final triumph in the Philippines does not end with mention of guerrillas, for thousands of other Filipinos aided the U.S. Army in many capacities. Filipinos contributed services of all types, as railroad men, truck drivers, engineers, clerks, government officials and employees, guides, spies, and carriers who often risked their lives hand-carrying supplies to the front lines. There is no doubt that the guerrillas and the other Filipinos made the task of the U.S. Army infinitely less difficult. It is, indeed, difficult to imagine how the Southwest Pacific Area could have undertaken the reconquest of the Philippines in the time and manner it did without the predominately loyal and willing Filipino population.
Though the end of the war came before the Philippines (and the Filipinos) could fulfill the roles planned for them in Japan’s inevitable defeat, the fact of Japan’s sudden collapse in no way detracts from the significance of the triumph in the Philippines. Hindsight arguments about the desirability and necessity of tying up strong American forces—sixteen divisions, or equivalent, in ground combat troops alone—in the reconquest of Luzon and the Southern Philippines may rage for decades to come, with justice and logic undoubtedly to be found on both sides of the argument. The fact remains that it was the consensus of military planners in the fall of 1944, when they decided to seize Luzon and bypass Formosa in favor of a jump to Okinawa, that the successful prosecution of the war against Japan demanded the reoccupation of Luzon. In the military-political milieu of October 1944, it is hard to imagine that the planners could have reached any other decision.