Battle of Peleliu

The Battle of Peleliu, codenamed Operation Stalemate II, was fought between 15 September and 27 November 1944 during the Mariana and Palau Islands campaign of the Pacific War. United States Marine Corps units of the 1st Marine Division—later reinforced by soldiers of the 81st Infantry Division—sought to capture the strategically located airfield on the small coral island of Peleliu, held by the Imperial Japanese Army. What had been forecast by American planners as a brief operation of four days extended into a brutal, two-month struggle due to the development of new Japanese defensive doctrines. The battle became one of the most controversial American operations of the war owing to its extremely high casualty rate and limited strategic value.

Background to the Campaign

By mid-1944 the Allied advance across the Pacific had placed Japan under growing pressure. Strategic debate in Washington centred upon the route of the final approach to the Japanese homeland. General Douglas MacArthur advocated a return to the Philippines before pushing on to Okinawa and then the Japanese archipelago. Admiral Chester Nimitz argued for bypassing the Philippines and instead seizing Taiwan and Okinawa. President Franklin D. Roosevelt’s visit to Pearl Harbor resolved the dispute in favour of MacArthur.
Before operations in the Philippines could begin, the southern flank required protection. The islands of Peleliu and Angaur were deemed significant because airfields could be constructed on them to support future operations. Although subsequent events showed the islands had limited long-term strategic value, the United States proceeded with their capture as part of Operation Forager, the broader offensive aimed at securing the Marianas and Palau groups.

Japanese Preparations and Defensive Strategy

Peleliu was defended by approximately 11,000 troops of the 14th Division, supported by Korean labourers and naval personnel. Command of the defence was entrusted to Colonel Kunio Nakagawa, whose force was regarded as a first-rate unit following its transfer from Manchuria.
After catastrophic losses in earlier campaigns, the Imperial Japanese Army undertook a comprehensive reassessment of its island defence strategy. Rather than oppose amphibious landings directly at the water’s edge, the new doctrine emphasised a prolonged defensive battle fought from concealed positions in inland high ground. On Peleliu the rugged coral ridges and steep slopes of Umurbrogol Mountain offered ideal terrain for this approach.
Nakagawa transformed the island into a heavily fortified stronghold. More than 500 limestone caves, many originally mined for phosphate extraction, were expanded and interconnected by tunnels. Engineers installed sliding steel doors, firing apertures and angled entrances designed to resist explosives and flamethrowers. Artillery and machine-gun positions were dispersed across a honeycomb system of bunkers. Beach defences included mines, buried shells fashioned as improvised charges and firing slits overlooking the main landing zones.
The garrison was equipped with mortars, anti-aircraft cannon, machine guns and a small number of light tanks. Its mission was to impose maximum attrition through a defence in depth, avoiding wasteful banzai charges. Nakagawa recognised that the garrison was unlikely to survive the battle; no evacuation plans were made.

American Planning and the Landing

American planners did not significantly modify previous amphibious doctrine despite developments in Japanese defensive practice. The 1st Marine Division selected the south-west beaches for the assault because of their proximity to the airfield, the principal objective. The landing plan assigned:

• 1st Marine Regiment under Colonel Lewis “Chesty” Puller to the northern beaches
• 5th Marine Regiment under Colonel Harold D. Harris to the centre
• 7th Marine Regiment under Colonel Herman H. Hanneken to the southern end
• 11th Marine Regiment to provide artillery support

Major General William Rupertus believed the island could be secured within days. However, the complex defences and the terrain transformed the operation into a prolonged battle of attrition.

The Ground Campaign

Initial landings on 15 September met intense fire from concealed positions, particularly from the promontory known to the Marines as The Point, where anti-tank and automatic guns swept the beaches. Although the Marines secured the airfield relatively quickly, progress inland slowed dramatically.
The central stronghold of Umurbrogol Mountain—later called “Bloody Nose Ridge” by American troops—became the focal point of the battle. Its maze of interlocking caves and defensive positions required extensive infantry assaults supported by flamethrowers, demolition teams, tanks and artillery. The fighting was characterised by short-range engagements and high casualties. The 1st Marine Division suffered such attrition that the 81st Infantry Division was brought from neighbouring Angaur to relieve and continue the reduction of the central ridges.
Operations extended into late November as Japanese positions were gradually isolated and destroyed. Colonel Nakagawa committed suicide on 24 November, marking the effective end of organised resistance.

Casualties and Losses

Losses on both sides were severe:

• United States total (Peleliu and associated operations):
  • Marine Corps and Army: Approximately 542 killed and 2,736 wounded or injured in the Palau Group; Marine Corps reports include 425 killed, 179 died of wounds, 2,313 wounded, and small numbers missing.
  • Navy casualties: 185 killed, 10–11 died of wounds, and 504 wounded, with an overall naval casualty total of 699 for the broader Palau operations.
• Japanese losses:
  • On Peleliu itself approximately 10,695 killed and 301 prisoners taken;
  • Angaur Island saw 1,338 killed and 59 prisoners;
  • Excluding stragglers, Japanese total deaths across the group amounted to over 12,000, with 360 prisoners.

These figures reflect the unprecedented lethality of the defensive network and the determination of the garrison to fight to the end.

Significance

Peleliu became known in Japanese accounts as “the Emperor’s Island” due to the defenders’ prolonged resistance. For the United States Marine Corps, it was later described as “the bitterest battle of the war”, with casualty rates exceeding those of any other American amphibious assault in the Pacific.
Strategically, the island’s value proved limited. Its airfield played only a minor role in subsequent operations and was overshadowed by the rapid success of the Philippine campaign. The high cost of the battle contributed to ongoing debates about the necessity of certain island assaults and highlighted the effectiveness of the new Japanese defensive methods that would later be encountered at Iwo Jima and Okinawa.