BG LaHue then launched Operation Cochise against the People's Army of Vietnam (PAVN) 2nd Division in the Quế Sơn Valley.

[3] In the early morning of 31 January 1968 as part of the Tet Offensive, the PAVN and Vietcong (VC) seized control of the city of Huế from the Army of the Republic of Vietnam (ARVN) 1st Division.

The Marines at Phu Bai were called on to support the ARVN 1st Division and US forces at the Military Assistance Command Vietnam (MACV) compound in the new city on the south side of the river.

"[3]: 171  On 1 February BG LaHue ordered Colonel Gravel's 1st Battalion, 1st Marines to move 6 blocks west from the MACV Compound and recapture the Thừa Thiên provincial headquarters and prison.

"[3]: 175  As with other commanders LaHue still did not appreciate the strength of the PAVN/VC forces in the city or their open supply lines; the Marines would not capture the provincial headquarters and prison until 6 February.

In his briefing of 1/5 Marines commander Major Robert Thompson, LaHue expressed his view that it would only take a few days to clear the Citadel.