The Joint Chiefs of Staff had directed Admiral Nimitz to support General MacArthur’s operation against Leyte. Admiral Nimitz ordered Admiral Halsey’s Third Fleet to “destroy enemy naval and air forces in or threatening the Philippine Area.” The Third Fleet was also to protect the air and sea communications along the Central Philippines axis. If an opportunity to destroy major portions of the Japanese Fleet should arise or could be created, such destruction was to be the primary task of all naval forces from the Central Pacific. Admiral Halsey and General MacArthur were to arrange the necessary measures for the co-ordination of their operations.[22]
In support of the Leyte operation the Third Fleet was to contain or destroy the Japanese Fleet and to destroy enemy aircraft and shipping in the Formosa, Luzon, Visayan, and Mindanao areas from 9 October through 17 October, and from A Day for as long as necessary during the next thirty days, in order to “maintain their continued neutralization.” From 18 October until such time as the escort carriers could assume direct support, the Third Fleet was to destroy enemy ground defenses and installations in Leyte and adjacent areas. Finally, the Third Fleet was to provide direct support by fast carrier aircraft for the landing and subsequent operations.[23]
Submarines from both the Southwest Pacific and Central Pacific were to support the operations by maintaining an offensive reconnaissance over the most probable Japanese route of advance, maintaining observation and lifeguard services and furnishing weather reports and strategic patrols. Submarines from the Central Pacific were to patrol in the Formosa, Luzon, Tokyo Bay, and Sasebo areas, while those from the Seventh Fleet patrolled in the area of Makassar Strait, the Celebes Sea, and the Sulu Sea. Submarines from both areas were to maintain a strong patrol in the Hainan—northern Luzon areas.[24]
The naval gunfire, the air support, and the artillery fire were to be carefully co-ordinated. At every level from battalion to army representatives from each support arm were to co-ordinate the use of their support arms against targets in their respective zones of action. Requests for support were to be screened as they passed through the various echelons for approval. Commanders in the field felt that the passage of requests through many channels was time consuming and consequently sometimes nullified what might have been an immediate advantage. However, requests for support were usually acted upon within an hour.
The Ground Forces
The ground forces designated for the Leyte operation came from two different theaters—the X Corps from the Southwest Pacific and the XXIV Corps from the Central Pacific. The XXIV Corps, originally intended for the Yap operation, had been substituted for the XIV Corps, originally intended for Leyte. As the new assignment of the XXIV Corps placed it under the operational control of General MacArthur, it was necessary that agreements on the co-ordination of operations be reached by the commanders in chief of the two areas. The XXIV Corps, with its original shipping, had been turned over to General MacArthur. During the combat phase at Leyte, General MacArthur was to furnish the replacements required by the XXIV Corps, but subsequent replacements were to be supplied by Admiral Nimitz.[25]
The initial assault for the island of Leyte was to begin in the dim half dawn of 17 October, when elements of the 6th Ranger Infantry Battalion were to land under the protection of naval gunfire and seize the small islands that guarded the entrance to Leyte Gulf. ([Map 3]) Harbor lights were to be placed on Homonhon Island and the northern tip of Dinagat Island in order to guide the passage of the convoy into the gulf. Since it was believed that there were valuable mine charts on Suluan, that island was added to the objectives of the 6th Rangers.
General Krueger had wanted to use either the reinforced 158th Infantry Regiment or the reinforced 112th Cavalry Regimental Combat Team to secure the island approaches to Leyte Gulf and the Panaon Strait area. The 21st Infantry, which was assigned the mission of securing the Panaon Strait area, then could have remained with the 24th Division, its parent unit, and the 6th Ranger Battalion could have been used wherever and whenever needed. In addition, these missions would have been put in the hands of a general officer who had an experienced staff to assist him. Neither of the desired regiments, however, could be made available for the Leyte operation because of shortage of troops and previous commitments.[26]
MAP 3 C. A. Frost