Battle of Peleliu


The Battle of Peleliu, codenamed Operation Stalemate II by the US military, was fought between the United States and Japan during the Mariana and Palau Islands campaign of World War II, from 15 September to 27 November 1944, on the island of Peleliu.
US Marines of the 1st Marine Division and then soldiers of the US Army's 81st Infantry Division fought to capture an airfield on the small coral island of Peleliu. The battle was part of a larger offensive campaign known as Operation Forager, which ran from June to November 1944 in the Pacific War.
Major General William Rupertus, the commander of the 1st Marine Division, predicted that the island would be secured within four days. However, after repeated Imperial Japanese Army defeats in previous island campaigns, Japan had developed new island-defense tactics and well-crafted fortifications, which allowed them to offer stiff resistance and extended the battle to more than two months. The heavily outnumbered Japanese defenders put up such staunch resistance, often fighting to the death in the name of the Japanese Emperor, that the island became known in Japanese as the "Emperor's Island."
In the US, the battle was controversial because of the island's negligible strategic value and the high casualty rate incurred by American troops during the fighting, which exceeded that of all other amphibious operations during the Pacific War. The National Museum of the Marine Corps called it "the bitterest battle of the war for the Marines".

Background

By 1944, American victories in the Southwest and Central Pacific had brought the war closer to Japan, with American bombers able to strike at the Japanese main islands from air bases secured during the Mariana Islands campaign. There was disagreement among the U.S. Joint Chiefs over two proposed strategies to defeat the Japanese Empire. The strategy proposed by General Douglas MacArthur called for the recapture of the Philippines, followed by the capture of Okinawa, then an attack on the Japanese home islands. Admiral Chester W. Nimitz favored a more direct strategy of bypassing the Philippines but seizing Okinawa and Taiwan as staging areas to an attack on the Japanese mainland, followed by the future invasion of Japan's southernmost islands.
The 1st Marine Division had already been chosen to make the assault. U.S. President Franklin D. Roosevelt traveled to Pearl Harbor to personally meet both MacArthur and Nimitz and hear their arguments. In the end, MacArthur's strategy was chosen. However, before MacArthur could retake the Philippines, the Palau Islands, specifically Peleliu and Angaur, were to be neutralized and an airfield built to protect the southern flank of MacArthur's planned landings on the Philippines.

Preparations

Japanese

By 1944, Peleliu was occupied by about 5,500 Japanese troops of the 14th Infantry Division. Considered a crack unit, the division had been detached from the Kwantung Army in Manchuria to garrison Peleliu after the fall of the Marshall Islands earlier in 1944, and had arrived on the island in May. Colonel Kunio Nakagawa, commander of the division's 2nd Regiment, led the preparations for the island's defense. In addition to these, there were about 4,000 naval troops, of whom about 1,500 of the 45th Base Guard Force were trained in the infantry role, the remainder were maintenance staff, air crews and other miscellaneous support troops. In addition to this, there was a large contingent of Korean and Japanese construction personnel.
After their losses in the Solomons, Gilberts, Marshalls and Marianas, the Imperial Japanese Army assembled a research team to develop new island-defense tactics. Previously, Japanese island garrisons had heavily contested enemy landings on the beach itself, rendering them vulnerable to naval bombardment. The Japanese formulated new tactics that envisioned only a token defense of the landing beaches, instead protracting the conflict by holding defensible terrain in the island interior. Peleliu's steep, twisting coral ridges were ideal for such a defense in depth. Colonel Nakagawa used this rough terrain to his advantage by ordering the construction of heavily fortified bunkers, caves, and other subterranean positions, all interlocked in a "honeycomb" system. Traditional "banzai charge" attacks were to be discontinued, as they wasted manpower and were ineffective. These changes in tactics were designed to force the Americans into a war of attrition, compelling them to spend more troops, materiel and time to secure Japanese island garrisons.
Nakagawa's defenses were centered on Peleliu's highest point. Located at the center of Peleliu, the hills and steep ridges of Umurbrogol Mountain overlooked much of the island, including its crucial airfield. The Umurbrogol contained some 500 limestone caves, connected via tunnel by Japanese engineers. Many of these caves were former mine shafts developed by Nanyo Kohatsu Kaisha, a Japanese firm established in 1921 primarily to develop the sugar industry in Saipan, where its headquarters were located. However, the company also owned and worked the phosphate deposits on Peleliu. The phosphate material was mined with native labor and transported via narrow gauge railcars operated by manpower to a phosphate refinery located at the wharf on Peleliu.
The mines and caves were turned into defensive positions. Engineers added sliding armored steel doors with multiple openings to many cave entrances, providing extra protection and concealment for artillery and machine guns. Cave entrances were opened or altered to be slanted as a defense against grenade and flamethrower attacks. The caves and bunkers were connected to a vast tunnel and trench system throughout central Peleliu, which allowed the Japanese to evacuate or reoccupy positions as needed, and to take advantage of shrinking interior lines.
The Japanese garrison was well armed with Type 97 81 mm infantry mortar| and mortars and Type 98 20 mm AA Machine Cannon| anti-aircraft cannons, backed by a light tank unit and an anti-aircraft detachment. The Japanese also used the beach terrain to their advantage. The northern end of the landing beaches faced a coral promontory that overlooked the beaches from a small peninsula, a spot later known to the Marines who assaulted it simply as "The Point". Holes were blasted into The Point to accommodate a gun and six 20 mm cannons. The positions were then sealed shut, leaving only a thin slit to fire on the beaches. The Japanese constructed similar positions along the stretch of landing beaches on the western shore of Peleliu.
The beaches were also filled with thousands of obstacles for the landing craft, principally mines and a large number of heavy artillery shells buried with the fuses exposed, designed to explode when they were run over. Nakagawa placed a battalion along the beach to defend against the landing, but this unit was meant to merely delay the inevitable American advance inland. Neither Nakagawa nor his superior officers expected the garrison to survive if Peleliu was attacked, and Japanese military planners made no contingencies to evacuate any survivors.

American

Unlike the Japanese, who drastically altered their tactics for the upcoming battle, the American invasion plan was unchanged from that of previous amphibious landings, even after suffering 3,000 casualties and enduring two months of delaying tactics while overcoming entrenched Japanese defenders at the Battle of Biak. On Peleliu, American planners chose to land on the southwest beaches because of their proximity to the airfield on south Peleliu. The 1st Marine Regiment, commanded by Colonel Lewis B. "Chesty" Puller, was to land on the northern end of the beaches. The 5th Marine Regiment, under Colonel Harold Harris, would land in the center, and the 7th Marine Regiment, under Colonel Herman Hanneken, would land at the southern end.
The division's artillery regiment, the 11th Marines under Colonel William Harrison, would land after the infantry regiments. The plan was for the 1st and 7th Marines to push inland, guarding the 5th Marines' flanks and allowing them to capture the airfield located directly to the center of the landing beaches. The 5th Marines were to push across to the eastern shore, cutting the island in half. The 1st Marines would push north into the Umurbrogol, while the 7th Marines would clear the southern end of the island. Only one battalion was held in reserve, with the U.S. Army's 81st Infantry Division available for support from Angaur, just south of Peleliu.
On 4 September the Marines shipped off from their station on Pavuvu, north of Guadalcanal, a trip across the Pacific. A Navy Underwater Demolition Team cleared the beaches of some obstacles as warships began their pre-invasion bombardment of Peleliu on 12 September.
The battleships,,, and, heavy cruisers,, and, and light cruisers, and, led by the command ship, subjected the island to a massive three-day bombardment, pausing only to permit air strikes from the three aircraft carriers, five light aircraft carriers, and eleven escort carriers that sailed with the attack force. A total of 519 rounds of shells, 1,845 rounds of shells and 1,793 bombs pounded Peleliu during this period.
The Americans believed the bombardment to be successful, as Rear Admiral Jesse Oldendorf claimed that the Navy had run out of targets. In reality, most Japanese soldiers survived; even the battalion left to defend the beaches was virtually unscathed. During the initial American assault, the island's defenders exercised unusual firing discipline to avoid giving away their positions. However, the bombardment destroyed Japan's aircraft on the island and the buildings surrounding the airfield. The Japanese remained in their fortified positions, waiting to attack the American landing troops.

Opposing forces

American order of battle

United States Pacific Fleet

Admiral Chester W. Nimitz

US Third Fleet

Admiral William F. Halsey Jr.
Joint Expeditionary Force

Vice Admiral Theodore S. Wilkinson
Expeditionary Troops

III Amphibious Corps

Major General Julian C. Smith, USMC
Western Landing Force

Major General Roy S. Geiger, USMC
1st Marine Division
  • Division Commander: Maj. Gen. William H. Rupertus, USMC
  • Asst. Division Commander: Brig. Gen. Oliver P. Smith, USMC
  • Chief of Staff: Col. John T. Selden, USMC
Beach assignments