The fall of Japan’s first line of defense in New Guinea, the Marshalls and the Marianas allowed the Allies to move on to strongholds in Japan’s second defensive line. The Palau Islands were stepping stones in Army General Douglas MacArthur’s plan to invade the Philippines. While it is still debated whether the capture of the Palaus was necessary to protect Gen MacArthur’s flank, the battle of Peleliu was one of the toughest to be fought during the entire Pacific war.
On 10 May 1944, the Commander in Chief, Pacific Fleet/Pacific Ocean Areas, Admiral Chester W. Nimitz, USN, issued the first planning orders for the assault on the Palau Islands of Peleliu and Angaur. Peleliu would be the primary target of the operation, which was code-named Stalemate II. The U.S. commanders of the campaign were assigned as follows:
–Vice Admiral Theodore S. Wilkinson, USN, commanded the Third Amphibious Force.
–Major General Roy S. Geiger, USMC, commanded the III Amphibious Corps, comprised of ground troops from the 1st Marine Division (Peleliu) and the Army’s 81st Infantry Division (Angaur).
–Major General William H. Rupertus, USMC, commanded the 1st Marine Division. Under his command were 1st Marines commander Col Lewis B. “Chesty” Puller, 5th Marines commander Col Harold D. Harris, 7th Marines commander Col Herman H. Hanneken and 11th Marines commander Col William H. Harrison.
–Major General Paul J. Mueller, USA, commanded the 81st Infantry Division.
D-Day on Peleliu was set for 15 September 1944. On that day, the 1st Marine Division planned to land on the western beaches of Peleliu three regiments abreast. The 1st Marines were to assault the beaches on the left, which were designated White 1 and White 2, and push through the enemy toward the northwestern peninsula of the island. In the center, the 5th Marines were to land on Orange Beaches 1 and 2 and drive across to the island’s eastern shore. They would be responsible for securing the island’s airfield before moving to seize the northeastern part of the island.
The 7th Marines on the right were to assault Orange Beach 3 and move to take the southern tip of the island.
The U.S. Navy demonstrated the value of sea power by blocking the Japanese access to sea lanes that would have enabled them to reinforce and resupply their men on Peleliu.
Three days of naval gunfire preceded the Marines’ landing, but it proved inadequate against the type of Japanese defenses created on the island. The Japanese took advantage of the rugged, ridged terrain around Umurbrogol Mountain (unreported by American reconnaissance units) to construct a series of interlocking underground shelters and well-concealed concrete bunkers. As U.S. troops came ashore, they faced enfilading fire from these bunkers and from the high ground above the beaches.
The enemy fought tenaciously to prevent the Marines from securing a beachhead. The first night ashore was grueling; small infiltration parties hit the Marine lines repeatedly. The cruiser Honolulu and three destroyers provided star shell illumination to help the Marines turn the infiltrators back, but the rest of the fleet withdrew to avoid enemy submarines. The Marines fought throughout the night, well dug in their foxholes. Water was in short supply as there were no natural sources the Marines could tap. According to one observer, by the morning 16th September, the Marines were “mean and thirsty.” That day, the 5th and 7th Marines advanced relentlessly; the 1st Marines more slowly, encountering fierce resistance from the northern ridges they were assigned to take.
Temperatures on Peleliu rose as high as 115 degrees, and drinking water was scarce during the initial combat. Marines on the front lines were parched, pleading for water. Hearing this, the crews of some of the ships offshore, to the surprise and delight of many Marines, sent cases of fruit and tomato juices ashore for the front line troops.
Brigadier General Oliver P. Smith, assistant 1st Marine Division commander, said of the first week of fighting, “Seven days after the landing, all of the southern end of Peleliu was in our possession, as well as the high ground immediately dominating the airfield. All the beaches that were ever used were in use. There was room for the proper deployment of all the artillery, including the Corps’ artillery. Unloading was unhampered except by the weather and hydrographic conditions. The airfield was available and essential base development work was underway.”
The battle for Peleliu provided an opportunity for Marines to practice and perfect their skills in close air support. Marine aviators demonstrated ingenuity and courage, but their efforts would have little effect on the underground fortresses built by the Japanese. Following the fighting, one report estimated the existence of more than 500 caves. Long-range flame throwers mounted on amphibian tractors, employed for the first time on Peleliu, proved to be the most effective weapon against these well-fortified caves.
In later phases of the operation, the seizure of Umurbrogol Mountain and the northern area of Peleliu were among the most difficult assignments faced by the Marines. This move was tactically important as a means to bypass and isolate enemy pockets of resistance. The northern ground was also to be used as a platform to attack the neighboring small island of Ngesebus. Ngesebus, connected to Peleliu by causeway, was an objective because of its unfinished fighter air strip.
The seizure of Umurbrogol Mountain took five regiments close to two months of battle to accomplish. Indeed, the 1st Marines suffered so many casualties as it fought to achieve its objectives that the Army’s 81st Infantry Division, known as the “Wildcats,” was called in to relieve them. The Wildcats’ initial mission to seize Angaur had been accomplished on 21 October when the division overran Angaur’s remaining resistance and the island was declared secure.
The Wildcats then began the tough job of relieving the 1st Marines and isolating the enemy pockets of resistance on Umurbrogol Mountain. Over the next weeks, the Wildcats would advance slowly around the Umurbrogol pocket, gradually eliminating all enemy resistance. Unlike earlier battles, the Japanese defenders did not attempt banzai (suicide) charges but continued to fight to the bitter end, hoping to inflict the greatest amount of damage to the American forces.
On 27 September, MajGen Geiger declared the island secure and ordered the American flag to be raised over the battlefield. Operation Stalemate II had become the Pacific’s largest amphibious operation thus far, involving more than 800 vessels and 1,600 aircraft.
Throughout the battle, U.S. naval forces had prevented the Japanese from reinforcing their troops on Peleliu, which assisted U.S. ground troops to gain a victory over the well-entrenched enemy force. Victory on Peleliu denied the Japanese a staging area for attacks on the U.S. fleet in the South Pacific and denied them as well the ability to communicate with their forces in the Philippines. The cost of taking the island, however, was high. On Peleliu, Marine casualties were 1,336 killed and 5,450 wounded while the 81st Infantry Division suffered 1,393 casualties including 208 killed in action. On Angaur, the 81st Infantry Division had 1,676 casualties, including 196 killed in action. The Japanese lost an estimated 10,695 men, with an additional 301 taken as prisoners of war.