On the evening of 17 November the Viet Cong (VC) 1st Regiment overran the Regional Force garrison defending the district capital of Hiệp Đức at the mouth of the Quế Sơn Valley. On the morning of 18 November as helicopters from Marine Aircraft Group 16 and Marine Aircraft Group 36 began landing 2 ARVN battalions on a landing zone 700m southwest of Hiệp Đức, they were hit by antiaircraft fire from VC 12.7mm machine guns in the adjacent hills which hit 17 out of 30 UH-34s and killed 1 Marine crewman. The helicopter landings were suspended while F-4Bs from Marine Aircraft Group 11 and A-4s from Marine Aircraft Group 12 attacked the antiaircraft positions. The helicopter landings were resumed and the ARVN repulsed an attack on the landing zone. By 19 November the ARVN had recaptured Hiệp Đức, killing 141 VC and capturing 87 weapons while losing 33 killed.
On 20 November the 2 ARVN battalions were withdrawn from Hiệp Đức to support a counterattack against a People's Army of Vietnam (PAVN) attack on Thach Tru in southern I Corps.:100
On 4 December III Marine Amphibious Force (III MAF) commander LG Lew Walt met with ARVN I Corps commander Gen. Nguyễn Chánh Thi to discuss the worsening security situation in the Quế Sơn Valley and they agreed to mount a joint operation there to neutralize the VC forces.:101
On 5 December III MAF activated Task Force Delta commanded by 3rd Marine Division deputy commander BG
Melvin D. Henderson to control the operation and the 3rd Battalion, 3rd Marines, the 2nd Battalion, 7th Marines and a provisional artillery battalion formed from the 11th and 12th Marine Regiments were assigned to Task Force Delta. By 7 December BG Henderson and his ARVN counterpart BG Hoàng Xuân Lãm commander of the 2nd Division, had completed planning the operation which called for the ARVN 5th Regiment comprising the 1st Battalion and the 11th Ranger Battalion to advance along Route 534 from Thăng Bình to Hiệp Đức on 8 December and then on 9 December the 2/7 Marines would be landed by helicopter southwest of Quế Sơn where the VC 1st Regiment was suspected to be operating and force them eastwards towards the ARVN force.:101-3