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World War II - War in the Pacific

The loss of the Philippines in May of that year, after the disaster that befell the U.S. Pacific Fleet at Pearl Harbor, rendered obsolete the American prewar plans for action in the Pacific in the event of war with Japan. In practice, operational control of the Pacific theater was vested in the American JCS, since there were no British Naval units in area.

Churchill argued for defeating Germany first, and Australia's prime minister, John Curtin, was equally insistent on receiving support in maintaining the sea lines of communication open to Australia and New Zealand, and blunting a potential Japanese invasion. Complicating Roosevelt's strategic dilemma was an American public which was thirsty for vengeance after Pearl Harbor. Development of any kind of cohesive strategy was hindered by inter-service rivalry, doctrinal differences, and strong personality conflicts.

At the Pacific theater level, the Army was represented by General Douglas MacArthur, an officer of enormous ambition, popularity, and political influence, who was intensely disliked within Navy circles. MacArthur's vision of conquest in the Pacific consisted of major land battles in the large island masses of the South West Pacific, culminating in the invasion of first the Philippines, then Japan.

MacArthur's in-theater Navy counterpart was the somber, and intensely professional, Admiral Chester Nimitz, later joined by the flamboyant and appropriately nick-named Admiral William "Bull" Halsey. Both officers lacked MacArthur's political influence. These men became disciples of Navy chief Admiral Ernest J. King's vision that victory in the Pacific was a function of a central island hopping campaign against smaller Japanese garrisons, with a strategic blockade of the Japanese homeland. This plan provided a better opportunity for threatening Japan's sea lines of communications, and bringing the Japanese fleet to battle.

Because of his popularity and seniority, the Army felt that MacArthur would be the logical choice for this command. This option was equally unacceptable to the Navy, who viewed MacArthur as a prima donna with an unimpressive track record. Eventually, the Joint Chiefs reached a compromise solution, dividing the theater into a South-West Pacific region under MacArthur, and a Northern and Central region under Nimitz.

Despite Churchill's insistence on giving priority to the European theater, King's position for strengthening the Pacific gained momentum in February of 1942, when Roosevelt agreed to support Curtin's request for the American defense of Australia and New Zealand. After the crushing Japanese defeat at Midway in June of 1942, Nimitz argued for the "Navy Plan" -- an island hopping thrust across the Central Pacific, while MacArthur advocated the "Army Plan .... a drive from the South-West Pacific through the Dutch East Indies Islands. The choice of routes implied subordinating one service to another, an unacceptable option to either service. After stormy debate, a compromise was reached in July 1942 -- the Southern route was chosen and divided into two regions. The Navy and Marines under Halsey were assigned the objective of advancing through the Solomons Islands; and the Army, under MacArthur, was assigned the objective of advancing into New Guinea.

King, over MacArthur's objection, finally gained approval for the Navy's Central Pacific Island hopping campaign at the Casablanca conference in January of 1943. But King's proposal for the accelerated reinforcement of the Pacific was outvoted by Marshall and Arnold in March of 1943.

By the late spring of 1943 the U.S. Joint Chiefs of Staff (who, by agreement of the U.S.-British Combined Chiefs of Staff, were responsible for the conduct of the war in the Pacific) had developed a new strategic plan for the defeat of Japan. The plan was neither sacrosanct nor immutable-it was not intended to be-but its underlying concepts governed the planning and execution of operations in the Pacific during a year and a half of debate over the relative priority of Luzon and Formosa as primary objectives of an Allied drive into the western Pacific.

The plan was premised upon the concept that the Allies might very well find it necessary to invade Japan in order to end the war in the Pacific. The Joint Chiefs of Staff foresaw that intensive aerial bombardment of the Japanese home islands would be prerequisite to invasion, and that such bombardment would have to be co-ordinated with combined air, surface, and submarine operations aimed at cutting Japan's overwater lines of communication to the rich territories she had seized in the Netherlands Indies and southeastern Asia.

The Joint Chiefs believed that the Allies could best undertake the necessary bombardment of Japan from airfields in eastern China. They decided that to secure and develop adequate air bases in China, Allied forces would have to seize at least one major port on the south China coast. The Allies would require such a port to replace the poor overland and air routes from India and Burma as the principal means of moving men and materiel into China.

To secure a port on the China coast, and simultaneously to cut Japan's line of communication to the south, the Allies would have to gain control of the South China Sea. Gaining this control, the Joint Chiefs realized, would in turn involve the seizure and development of large air, naval, and logistical bases in the strategic triangle formed by the south China coast, Formosa, and Luzon. But before they could safely move into this triangle, the Joint Chiefs decided, the Allies would have to secure air bases in the southern or central Philippines from which to neutralize Japanese air power on Luzon. The Allies might also need staging bases in the southern and central Philippines from which to mount amphibious attacks against Luzon, Formosa, and the China coast.

In accordance with these 1943 plans, Allied forces in the Pacific had struck westward toward the strategic triangle along two axes of advance. Air, ground, and naval forces of the Southwest Pacific Area, under General Douglas MacArthur, had driven up the north coast of New Guinea to Morotai Island, lying between the northwestern tip of New Guinea and Mindanao, southernmost large island of the Philippine Archipelago. Simultaneously, Admiral Chester W. Nimitz, commander of the Pacific Ocean Areas, had directed the forces of the Central Pacific Area in a drive through the Gilberts, Marshalls, and Marianas to the Palau Islands, some 500 miles east of Mindanao.

One of the thorniest problems of strategic planning for the war against Japan was to decide whether the principal objective of drives that had brought the Allies into the western Pacific should be Luzon or Formosa. The decision was made by the U.S. Joint Chiefs of Staff, since the Pacific was an American area of strategic responsibility. They made it after long debate and careful study of the views of the commanders in the Central and Southwest Pacific theaters. Among the considerations that determined their choice when they finally made it, logistical factors played the major role, but here, as in other connections, they had to take into account the commitments and progress of the Allies in other theaters, and particularly in Europe. It was in this sense a decision in global strategy.

The Joint Chiefs and their subordinate advisory committees concluded that Formosa constituted the most important single objective in the target area. The island possessed so many obvious advantages and was located in such a strategically important position that most planners in Washington believed the Allies would have to seize it no matter what other operations they conducted in the western Pacific. Until they seized Formosa, the Allies would be unable to establish and secure an overwater supply route to China. Formosa, therefore, seemed a necessary steppingstone to the China coast. Moreover, Allied air and naval forces could sever the Japanese lines of communication to the south much more effectively from Formosa than from either Luzon or the south China coast alone. Furthermore, from fields in northern Formosa, the Army Air Forces' new B-29's could carry heavier bomb loads against Japan than from more distant Luzon.

General George C. Marshall, Chief of Staff and Army member of the Joint Chiefs, played a relatively inactive part in the debate until late 1944, but at one time at least seemed inclined toward bypassing both the Philippines and Formosa in favor of a direct invasion of Kyushu in southern Japan. Some officers high in Army councils, including Lt. Gen. Joseph T. McNarney, Deputy Chief of Staff, strongly advocated bypassing the Philippines on the way to Formosa. General Henry H. Arnold, Army Air Forces member of the Joint Chiefs, also appears to have maintained through much of 1943 and 1944 that it might prove desirable to bypass the Philippines.

Other Army planners, including those of the chief logistician, Lt. Gen. Brehon B. Somervell, commander of the Army Service Forces, favored taking the entire Philippine Archipelago before making any move toward Formosa or the China coast. In the field, General MacArthur stood adamant against bypassing any part of the Philippines, a stand in which he had the support of most other ranking Army officers in the Pacific.

Developments in the Pacific, Asia, and Europe between mid-March and mid-June 1944 tended to support those planners who wanted to bypass the Philippines. The U.S. Army had acquired new intelligence indicating that the Japanese were rapidly reinforcing their bastions throughout the western Pacific, including Formosa. Thus, the longer the Allies delayed an attack on Formosa, the more the operation would ultimately cost. Army planners suggested that the Allies might be able to reach Formosa during November 1944 if the Joint Chiefs immediately decided to bypass the Philippines.

The Joint Chiefs were probably also stimulated by the success of the invasion of Normandy in early June and by the impending invasion of the Marianas in the Central Pacific, set for 15 June. At any rate, on 13 June, seeking ways and means to accelerate the pace of operations in the Pacific, and feeling that the time might be ripe for acceleration, the Joint Chiefs asked Admiral Nimitz and General MacArthur to consider the possibilities of bypassing all objectives already selected in the western Pacific, including both the Philippines and Formosa. The Joint Chiefs' subordinate committees, examining the theater commanders' replies and undertaking new studies of their own, reaffirmed the concept that the Allies would have to move into the central or southern Philippines before advancing to either Formosa or Luzon.

Saipan and Tinian in the Marianas lay closer to Tokyo than Nimitz' proposed base area in southern Formosa, and the two islands of the Marianas were secure from Japanese air attack. Finally, assuming that Nimitz could meet the most optimistic target date for the invasion of southern Formosa-1 March 1945-B-29'S could not begin operations from that island until the late spring or early summer. The Army Air Forces was already planing to initiate B-29 operations from the Marianas before the end of 1944. In brief, by mid-September, the Army Air Forces had lost interest in Formosa and had begun to see eye to eye With other Army elements on the disadvantages and drawbacks of the southern Formosa-Amoy scheme.

An obvious political consideration may have had a bearing on the ultimate decision in the Luzon versus Formosa debate. General Mac-Arthur's argument that it would be disastrous to United States prestige to bypass any part of the Philippines could not be dismissed. Perhaps more important, Admiral Leahy took the same point of view. By virtue of his intimate contact with President Roosevelt, it must be presumed that his colleagues of the Joint Chiefs of Staff gave Leahy's opinion careful consideration.

By the end of September 1944 almost all the military considerations-especially the closely interrelated logistical problems concerning troops and timing-had weighted the scales heavily in favor of seizing Luzon. Admiral Nimitz withdrew whatever support he was still giving the Formosa plan. He had concluded that sufficient troops could not be made available for him to execute the southern Formosa-Amoy campaign within the foreseeable future. Accordingly, at the end of September, he threw the weight of his opinion behind the Luzon operation, proposing that plans to seize Formosa be at least temporarily dropped. Simultaneously, Nimitz presented for Admiral King's consideration a planned series of operations designed to maintain steady pressure against the Japanese and carry Allied forces speedily on toward Japan: MacArthur's forces would initiate the Luzon campaign on 20 December 1944; Central Pacific forces would move against Iwo Jima, in the Volcano Islands some 650 miles south of Tokyo, late in January 1945; and the Central Pacific would next attack Okinawa, 850 miles southwest of Tokyo, and other targets in the Ryukyu Islands, beginning on 1 March 1945.

In the Pacific Ocean Areas, the penetration of Japan's outer defense was completed with the seizure and occupation of Saipan, Guam, and Tinian in the Marianas. Operations had been launched in February to reduce the island of Iwo Jima and establish it as a base for fighter planes to support the Marianas-based B-29 bombers. With the capture of this important island in the Bonins a month later, the United States gained possession of a strategic military position only 750 miles from Tokyo and pushed its forces far into Japan's inner line of island fortifications.

The millions of enemy troops in Asia and in the islands of the Pacific could never contract their lines to keep pace with the ever-narrowing arena of conflict. They were unable to conduct an orderly retreat in classic fashion to fall back on inner perimeters with forces intact for a last defense of Japan's main islands. It was a situation unique in modern warfare. Never had such large numbers of troops been so effectively outmaneuvered, separated from each other, and left tactically impotent to take an active part in the final battle for their Homeland.

With his conquest of the Philippines, General MacArthur had thrust a solid wedge deep into the heart of Japan's war-acquired empire. His battling forces in the Pacific had advanced more than 3,000 miles through enemy-controlled sea and land areas without a single defeat.

Despite Nimtz's and Air Force General Curtis LeMay's assertion that a strategic blockade and air offensive would defeat Japan, pressure from MacArthur and Marshall resulted in the development of plans for the invasion of the Japanese mainland. These plans were developed despite estimates of over a million American casualties. In the end, neither the Army nor Navy Plan was implemented. President Truman, responding to increasing domestic pressure for a quick end to the war, authorized the atomic bombings of Hiroshima and Nagasaki in August of 1945.

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Page last modified: 17-03-2021 18:03:22 ZULU