1944 battle between the United States and the Empire of Japan in the Pacific Theater of World War II
The Battle of Peleliu produced the highest casualty rate of any Pacific War amphibious operation, yet yielded minimal strategic gain.
Key Facts
- Duration
- 15 September – 27 November 1944 (73 days)
- US Divisions Engaged
- 1st Marine Division, 81st Infantry Division
- Predicted Duration
- 4 days (Maj. Gen. Rupertus estimate)
- US Casualty Rate
- Highest of any Pacific War amphibious operation
- Japanese Nickname
- Emperor's Island
- Operation Codename
- Operation Stalemate II
By the Numbers
Location
Cause → Event → Consequence
As part of Operation Forager and the broader Mariana and Palau Islands campaign, US commanders sought to neutralize a Japanese airfield on Peleliu that was perceived as a threat to planned operations in the Philippines. Japan, having suffered repeated defeats in earlier island campaigns, had developed new defensive tactics centered on fortified cave networks and fighting to the death rather than mounting beach defenses.
Beginning on 15 September 1944, US Marines of the 1st Marine Division assaulted the small coral island of Peleliu, later reinforced by the Army's 81st Infantry Division. Japanese defenders used the island's ridgeline cave systems and new attrition-based tactics to resist far longer than anticipated, turning a projected four-day operation into over two months of brutal close-quarters combat.
The battle ended on 27 November 1944 with US forces securing the island, but at a casualty rate exceeding all other Pacific amphibious operations. The strategic value of Peleliu proved negligible, as the anticipated threat to the Philippines never materialized. The engagement was later described by the National Museum of the Marine Corps as 'the bitterest battle of the war for the Marines,' and fueled lasting controversy over the decision to fight it.
Belligerents & Mobilization Analysis
Side A
1 belligerent
William Rupertus.
Side B
1 belligerent