In the south, from D plus 1 through D plus 3, the 7th Marines was in vigorous assault against extensive fortifications in the rear of the Scarlet Beaches. These were defended by a full battalion, the elite 2d Battalion, 15th Regiment. Although isolated and surrounded by the Marines, this battalion demonstrated its skill and its understanding of Colonel Nakagawa’s orders and mission: to sell Peleliu at the highest possible price. The 7th Marines attacked with 3/7 on the left and 1/7 on the right. They enjoyed the advantage of attacking the extensive and well-prepared defenses from the rear, and they had both heavy fire support and the terrain for limited maneuver in their favor. Both sides fought bitterly, but by 1530 on 18 September (D plus 3), the battle was substantially over. The Marines had destroyed an elite Japanese reinforced infantry battalion well positioned in a heavily fortified stronghold. Colonel Hanneken reported to General Rupertus that the 7th Marines’ objectives he had set for D-Day were all in hand. The naval gunfire preparation had been significantly less than planned. The difference had been made up by time, and by the courage, skill, and additional casualties of the infantry companies of 1/7 and 3/7.
Now the 7th Marines, whose 2d Battalion was already in the thick of the fight for Umurbrogol, was about to move out of its own successful battle area and into a costly assault which, by this time, might have been more economically conducted as a siege.
Maneuver and Opportunity
As the 7th Marines moved to its mission, the 5th Marines was again successfully opening up opportunities on Peleliu’s eastern, “lobster claw” peninsula. Most of those opportunities, unfortunately were never exploited.
By the end of D plus 2, the 5th Marines stood at the approach to the eastern peninsula, and astride the East Road just east of the 1st Marines’ terrible struggle in Umurbrogol. It had fought somewhat clear of the galling fires from Umurbrogol, and planned an assault on the eastern peninsula across a narrow causeway, which the Japanese should certainly defend. Then a D plus 3 reconnaissance of the causeway revealed that the causeway was not defended. The 2d Battalion hastened to seize the opportunity and moved across in strength. The attack was hit by its own supporting fires. The forward battalion CP group was strafed by Navy planes and then hit by artillery airburst, causing the loss of 18 battalion headquarters personnel to “friendly fire.”
Nevertheless, a bridgehead across the causeway was well established on D plus 3, and the 5th Marines’ Colonel Harris moved to exploit it. During the afternoon, he thinned his forces holding the East Road sector, gave the former 3/5 mission to Company L, 3/5, and gave the remainder of 3/5 a new mission. He ordered Gustafson into a position within the bridgehead established by 2/5, and further ordered both battalions then to capture and clear the eastern peninsula. Earlier he had expected such an attack to be against the strong defending forces originally reported on the eastern peninsula. However, the apparent reduction of defending forces now appeared to offer an opportunity to seize Purple Beach quickly, a logistic prize of some significance. Harris knew that the division would need to shift its logistical axis to Purple Beach, away from the fire from Umurbrogol, and away from the threat of westerly storms.
Before dark, Gustafson moved two of his 3/5 companies across the causeway, and moved his own CP group in with the 2/5 CP, where the two commanders jointly planned the next day’s advance. Hoping for little resistance, they directed rapid movement, but armed their point units with war dog sections to guard against ambush. Their lead companies moved out just after dawn. In the 3/5 sector, there was an ambush, but the war dogs warned of, and effectively thwarted, the attempted surprise.
Department of Defense Photo (USMC) 96936