Although no specific islands were named in the Strategic Plan, the Philippine Archipelago, because of its strategic position and long possession by the United States, naturally loomed large in the planning. The Philippines lie athwart all sea routes south from Japan to the economically important Netherlands Indies—rich in rubber, tin, oil, and rice. The capture of the Philippines would help to sever this line of communications and would furnish an excellent staging area for attacks against China, Formosa, or Japan. Aside from strategic considerations, the liberation of the Islands was important for reasons of Far Eastern politics and prestige.[6] The obligation of the United States to the subjugated Filipino people could not be lightly ignored. Furthermore, General MacArthur was imbued with a burning determination to return to the Philippine Islands and avenge the humiliating defeats suffered by the American forces in 1941 and 1942.
By the spring of 1944 the operations in the Pacific were going so well that the successes had exceeded even the most optimistic hopes of any of the planning officers. On 12 March the Joint Chiefs ordered General MacArthur to prepare plans for a return to Mindanao, southernmost island of the Philippines, with a target date of 15 November 1944.[7] General MacArthur on 15 June issued a plan for his future operations. The entrance into the Philippines was to be accomplished in two phases. The first would be a preliminary operation on 25 October into the Sarangani Bay area in southern Mindanao in order to establish land-based air forces to augment the carrier-based air support for the principal effort. The major effort was to be an amphibious landing operation with forces mounted from New Guinea for the seizure on 15 November of airfields and bases on Leyte.[8] The latter was to follow quickly on the heels of the first operation in order to take full advantage of the surprise tactics.
Leyte occupies a commanding position in the Philippine Islands. Because of its central location, its repossession by the United States would not only divide the Japanese forces in the Philippines but would also provide an excellent anchorage in Leyte Gulf, together with sites for bases and airfields from which land-based aircraft could bomb all parts of the Philippines, the coast of China, and Formosa. To an even greater extent than Mindanao, Leyte could be made into an excellent springboard from which to launch subsequent operations against the Japanese in Formosa or in the rest of the Philippines.
In his planning, General MacArthur recognized that the Leyte operation, his most ambitious to date, would require “massed carrier-based air support” and all of the “combined amphibious and naval forces available at the time.”[9]
By June 1944 General MacArthur’s forces had pushed up the New Guinea coast to the island of Biak, about nine hundred nautical miles southeast of Davao, Mindanao, while those of Admiral Nimitz were poised to strike at Saipan some twelve hundred miles northeast of Davao. In most of their previous campaigns the Americans had struck with overwhelming force at weakly held Japanese garrisons. Since the tide of war was now so favorable to the Allied cause, the Joint Chiefs thought that the Pacific timetable of pending operations might be accelerated. On 13 June they had therefore asked MacArthur and Nimitz their opinions with regard to three ways proposed for speeding up operations: “(a) By advancing target dates of operations now scheduled through operations against Formosa; (b) By by-passing presently selected objectives prior to operations against Formosa; and (c) By by-passing presently selected objectives and choosing new ones including the home islands.” Although the Philippine Islands were not explicitly named as targets that might be bypassed, they were certainly included by implication.[10]
On 18 June General MacArthur replied to the query of the Joint Chiefs,[11] and on 4 July Admiral Nimitz made known his opinions.[12] On the advancement of the target dates, both commanders were in complete agreement—it was impossible unless certain conditions could be changed. The logistic resources in the Southwest Pacific were being strained to the limit to meet the fixed target dates, while the strengthening of Japanese garrisons made it unlikely that the Central Pacific could make its present scheduled dates.
With respect to bypassing objectives prior to the seizure of Formosa, MacArthur thought it would be “unsound” to bypass the Philippines and launch an attack across the Pacific directly against Formosa—an attack which would have the benefit of no appreciable land-based air support and which would be based upon the Hawaiian Islands, 5,100 miles away. In his opinion it was essential to occupy Luzon and establish land-based aircraft thereon before making any move against Formosa.[13] Nimitz stated that in a series of informal discussions between his and MacArthur’s planning officers, the latter anticipated the seizure in early September of Morotai Island, 300 statute miles southeast of Mindanao. This was to be followed in late October by a limited occupation of the Sarangani Bay area on Mindanao, which was to be used primarily as a base for short-range aircraft. The major operation was to be the occupation of Leyte about 15 November. Nimitz thought that this timing was “optimistic.” He felt that the critical and decisive nature of the Leyte operation required “practically all available covering and striking forces, fire support forces, and all available assault shipping.” If successful, however, the Americans would achieve air supremacy over the Philippines. Therefore, since the inclusion of the Leyte operation with that of Mindanao would expedite subsequent operations, Nimitz considered it “advisable.”[14]
As to the feasibility of bypassing present objectives and choosing new ones, including the Japanese home islands, the two commanders were not in complete agreement. MacArthur pronounced the concept “utterly unsound,” since the available shipping was limited to a seven-division lift and there was insufficient air support. Nimitz thought that no decision should be made until after further developments.
The proposals disturbed General MacArthur, who concluded his message to the Joint Chiefs with the following peroration:
It is my opinion that purely military considerations demand the reoccupation of the Philippines in order to cut the enemy’s communications to the south and to secure a base for our further advance. Even if this were not the case and unless military factors demanded another line of action it would in my opinion be necessary to reoccupy the Philippines.