In a savage ten-day battle, the CCF 38th Army used an estimated 23,000 infantry and supporting troops in an attempt to capture the vital White Horse Hill complex which protected the Chorwon area and road net supplying IX Corps. With tanks and quad-50's protecting their flanks, and supported by massive artillery barrages totaling over 185,000 rounds, ROK 9th inflicted an estimated 10,000 casualties before the CCF finally stop their assaults. Among their diversionary attacks, the CCF assaulted Arrowhead (Hill 281) but was driven back three separate times with heavy losses, by the French battalion.

Another diversionary attack, on Jackson Heights (Hill 281), was more successful. The Puerto Rican 65th Regiment had taken heavy losses at OP Kelly and was still not fully combat ready, but bore the brunt of the fighting. When company and platoon leaders became casualties the lack of experience and depth at company combat levels became apparent and the position was lost. US 15th Regiment, 3rd Infantry Division later counter-attacked and kept tenuous holds on a few OPs at the base of the Hill.

When Eighth Army launched Operation Showdown against the Triangle Hill Complex in October, the CCF were able to force a stop to the attack, substantially making up for their defeat at White Horse.