$Unique_ID{USH00939} $Pretitle{87} $Title{The War Against Japan Section III The Offensive - 1941} $Subtitle{} $Author{Greenfield, Kent Roberts, General Editor} $Affiliation{US Army} $Subject{islands enemy island air japanese forces naval new troops area} $Volume{CMH Pub 12-1} $Date{1988} $Log{Specialized Training*0093901.scf Waterproof Jeep*0093902.scf Gun Emplacement*0093903.scf Enemy Plane*0093904.scf Tokyo Local*0093905.scf Questioning the Enemy*0093906.scf Buffalo*0093907.scf Water Depot*0093908.scf } Book: The War Against Japan Author: Greenfield, Kent Roberts, General Editor Affiliation: US Army Volume: CMH Pub 12-1 Date: 1988 Section III The Offensive - 1941 The battle of production and supply, designed to build a foundation to support unprecedented Allied air and naval power, was won during 1942 and 1943, while Japanese air and naval power greatly diminished. Hawaii, the most important naval base in the Pacific, had become a training center and staging area for U.S. troops as well as one of the many important supply bases. In 1944, the strategic offensive against Japan began. Following the invasion of the Gilberts in late 1943, U.S. forces prepared for an assault in the western Marshalls, the principal objective being Kwajalein and Eniwetok Atolls. According to plans for the assault on the western Marshalls, a Marine division was to seize the northern half of the Kwajalein Atoll, principally the islands of Rol and Namur; Army ground forces units were to capture the southern half of the atoll, including the island of Kwajalein, and to occupy Majuro Island, one of the finest naval anchorages west of Pearl Harbor. Supporting naval and air bombardment and artillery fire (the artillery had been ferried ashore on the small near-by islands) were brought to bear on the selected landing beaches of Kwajalein and Roi Islands of Kwajalein Atoll. Unopposed landings were made on both islands on 1 February 1944, with slight resistance developing after advance was made inland. Six days after the main landings, all the islands of the Kwajalein Atoll were in U.S. hands and Majuro had been occupied. On 17 February landings were made on the islands of Eniwetok Atoll; resistance was wiped out five days later. A two-day strike against Truk, 16 and 17 February, was executed by a large carrier task force to screen the assault of the Eniwetok Atoll and to test strength of the Japanese base there. Although the strong enemy island bases in the eastern Marshalls were bypassed, the air forces maintained continual attacks on them throughout the year. Conquest of the western Marshalls provided air bases and a new forward fleet base in the Pacific. The Mariana Islands, the next objective in the Central Pacific, differ from the coral atolls of the Marshalls and Gilberts. The individual islands are much larger and the distinguishing terrain features are precipitous coast lines, high hills, and deep ravines. Plans were made, ships and supplies collected, and the troops given special training for the invasion; meanwhile Japanese air and ground reinforcements poured into the Central Pacific. An intense air offensive against enemy installations in the Marianas began on 11 June 1944 and a naval bombardment of Saipan began on the 13th, two days before the landings on the 15th. Opposition was heavy at first, but by the 25th U.S. troops, supported by tanks, heavy artillery, renewed naval gunfire, and aerial bombardment, drove the enemy from the high ground on the central part of the island. Again advances were slow and difficult with heavy troop losses. On 9 July the mission was completed, except for mopping-up operations which continued for nearly two months. On the morning of 24 July an attack was made on Tinian, supported by artillery on Saipan. Enemy resistance, slight for first two days, increased when high ground was reached in the central part of the island. The entire island was overrun by 1 August. Meanwhile, Guam had been invaded on 21 July by U.S. forces in two separate landings. This invasion was preceded by a thirteen-day aerial and naval softening-up process. The two beachheads were joined after three days of fighting. The troops, greatly hampered by heavy undergrowth, concentrated on the high ground in the northern part of the island and, except for resistance from small groups of scattered Japanese, were in command of the island by 10 August. A force of nearly 800 ships from the Guadalcanal area sailed for the Palau Islands, the next hop in the Central Pacific. Marines landed on Peleliu Island on 15 September while Army units landed on Angaur on the 17th. These were the two southernmost islands of the Palau group. Opposition on Angaur was relatively light. Much stiffer resistance was met on Peleliu, which contained the site of the major Japanese airfield on the islands. The troops succeeded, by 12 October, in pushing the enemy into a small area in the central hills of Peleliu, but many more weeks were spent destroying the remaining opposition. During the fighting in the southern Palaus, Ulithi Atoll in the western Carolines was taken to secure a naval anchorage in the western Pacific. Air attack against bypassed islands was maintained. Meanwhile, huge air bases were being developed in the Marianas for use by B-29 bombers. On 24 November B-29's operating from Saipan made the first of a series of attacks on Tokyo. Concurrent with the operations in the Marshalls, Marianas, Palaus, and Carolines, forces of the Southwest Pacific Area moved swiftly along the northern coast of New Guinea, jumped to Vogelkop Peninsula, and then to Morotai and on into the Philippines. The first amphibious advance of 1944 in this area was made on 2 January at Saidor, to capture the airport there. The next major advance was begun early on the morning of 29 February when a landing was effected on Los Negros in the Admiralty Islands. The Japanese sent reinforcements from Manus Island, separated from Los Negros by only 100 yards of water. Except for isolated groups of enemy troops, Los Negros was cleared on the 23d and Momote airfield, on the east coast, was ready for operation. Manus Island was invaded on 15 March, after the seizure of a few smaller islands, and an airfield there was captured the next day. At the end of April most of the enemy had been cleared from the Admiralties. In New Britain the beachheads established in 1943 were expanded. On 6 March another landing took place on Willaumez Peninsula on the north coast. This operation, together with the establishment of airfields in the Admiralties and the occupation of Green and Emirau Islands, completed the encirclement and neutralization of Rabaul, the once powerful Japanese base. On 26 November U.S. units left New Britain, the enemy being contained on the Gazelle Peninsula by the Australians. In New Guinea, after the Saidor operation, the enemy organized his defenses in the coastal area between Wewak and Madang. Surprise landings by U.S. troops were made at Aitape and Hollandia, both west of Wewak, on 22 April. Within five days the airfields at Hollandia and Aitape were in Allied possession. In July 1944 the Japanese Army, which had moved up the coast from Wewak, attacked the Allied perimeter at Aitape. Within a month the Japanese had been thrown back toward Wewak. At the end of the year Australian troops, which had begun relieving U.S. forces at Aitape in October, started a drive on Wewak from the west. While the enemy was bottled up in this area, the Allies continued to leap-frog up the New Guinea coast. On 17 May forces debarked at Arare, 125 miles northwest of Hollandia, and established a strong beachhead. Wakde Island, just offshore, was assaulted the next day and was secured by the 19th. Other units assaulted the island of Biak on 27 May to seize additional air base sites. Here considerable resistance was met and the island with its airfields was not secured until August. Noemfoor Island, where three airfields were located, was invaded on 2 July by troops which landed at points where reefs made invasion hazardous. The Noemfoor airstrips were captured by night of the 6th. The last landing on New Guinea was an unopposed one made on 30 July in the Cape Sansapor area, on the northwestern coast of the Vogelkop Peninsula. The Japanese in New Guinea had been eliminated from the war. Another air base site on the southern tip of Morotai Island, northwest of the Vogelkop Peninsula, was seized on 15 September at slight cost. The invasion of Morotai, lying between New Guinea and the Philippines, was the last major operation undertaken by Southwest Pacific forces before the attack on the Philippines in October. Prior to the invasion of the Philippines a seven-day air attack, beginning on 10 October, was undertaken against enemy bases on the Ryukyu Islands, Formosa, and Luzon. On 17 October, Suluan, Homonhon, and Dinagat Islands, guarding Leyte Gulf where the main invasion was to be made, were captured. Despite all this activity, strategic surprise proved complete when, on 20 October 1944, the assault forces landed on Leyte. Heavy opposition was encountered on only one of the many beaches. Throughout the entire campaign, opposition at times was fierce although it came from relatively small units or from separate defense positions. Between 23 and 26 October the naval battle for Leyte Gulf took place. The enemy made every effort to hold Leyte; reinforcements were rushed in by every means available to them and during November an all-out struggle for Leyte developed. Bad weather conditions in November seriously interfered with the supply of U.S. forces and with air operations. On 7 December U.S. troops landed on the west coast of Leyte at Ormoc to place new strength at the rear of Japanese forces holding out in northwestern Leyte and to prevent the Japanese from landing any more reinforcements in the Ormoc area. By 26 December Leyte was declared secured but mopping up against strong resistance continued for several months. [See Specialized Training: Hip-shooting with 30-caliber machine guns during jungle training. Emphasis was placed on specialized training in patrolling, ambushing, hip-shooting, stream-crossing expedients, and jungle living. Training was also given in the assault of fortified areas, hand-to-hand combat, and the use of demolitions. As the varied problems of assaulting the Pacific islands arose, the training was changed to suit the particular requirements.] [See Waterproof Jeep: WATERPROOFED JEEP heading from ship to shore during the Kwajalein battle. Jeeps were prepared for fording by sealing the individual components and extending air and exhaust vents above the water level. Artillery that was ferried ashore on the smaller islands registered its fire on the selected landing beaches of Kwajalein and Roi, shifting fire inland two minutes before the leading assault waves hit the beaches.] [See Gun Emplacement: A .50-CALIBER MULTIPLE MACHINE GUN EMPLACEMENT] [See Enemy Plane: A single-engine Japanese fighter plane found on Saipan. Japanese aircraft markings usually consisted of a large red disc on the top and bottom of the outer section of each wing and on each side of the fuselage. The side marking was omitted on their Army aircraft but retained on Navy aircraft. Occasionally the red disc was surrounded by a narrow white line.] [See Tokyo Local: BOEING B-29 SUPERFORTRESS, the "Tokyo Local," taking off from Saipan to bomb Tokyo. Superfortress made the first of a series of attacks on Tokyo on 24 November 1944, operating from Saipan.] [See Questioning the Enemy: CAPTURED ENEMY SOLDIER BEING QUESTIONED at Aitape. The operation there gave the Allies another airstrip.] [See Buffalo: LAKE SENTANI NEAR HOLLANDIA. Men in a "Buffalo," LVT(A) (2), are firing a machine gun at enemy riflemen hidden in the bushes.] [See Water Depot: WATER SUPPLY POINT set up near a beach on Leyte, 21 October; note the collapsible water tank. By the end of the 21st, Tacloban, San Jose, Dulag, and two airfields were captured. Heavy fighting continued at palo.]