At the end of 1969, Major general
Melvin Zais, commanding US
XXIV Corps in I Corps, proposed breaking up the 1st Division (with four regiments and about nineteen combat battalions) into two divisions controlled by a "light corps" headquarters responsible for the defense of the
Vietnamese Demilitarized Zone (DMZ) area, but his immediate superior, Lieutenant general
Herman Nickerson Jr. (USMC), commanding the
III Marine Amphibious Force (and the I Corps senior adviser) and General
Hoàng Xuân Lãm, the I Corps commander, both vetoed the idea, citing the lack of enough experienced Vietnamese officers to staff a new command. In July 1971, rather than move one of the
Mekong Delta based ARVN divisions north, as recommended by General
Robert E. Cushman Jr., the
IV Corps senior adviser,
COMUSMACV General
Creighton Abrams went along with
Joint General Staff chief General
Cao Văn Viên's decision to create the new 3rd Infantry Division from existing regular and territorial elements in I Corps. Five out of its nine infantry battalions and its armored cavalry squadron were all units with long combat records, having fought
People's Army of Vietnam (PAVN) forces in the DMZ area for several years. Its other four infantry battalions were transferred as complete units, not piecemeal, from ARVN and territorial forces of I Corps. The Division was generally responsible for Quảng Trị Province, despite its proximity to the DMZ, it was believed that the PAVN would not make a direct attack across the DMZ and so it was regarded as a safe area for the Division to form and train in. Early on the morning of 1 April under pressure from the PAVN the 4th Vietnamese Marine Corps Battalion abandoned
Firebase Sarge and retreated to Mai Loc Camp. Trưởng's mission was to defend Huế, minimize further losses, and retake captured territory. Giai, who was to be made the scapegoat for the collapse, was placed under arrest on 5 May and tried for "desertion in the face of the enemy", and sentenced to five years in prison. The 3rd Division at this time consisted of only its headquarters and the remnants of the 2nd and 57th Regiments. The 51st was able to advance only part way up Hill 1460 and could not dislodge the PAVN infantry holding the crest. Meanwhile, elements of the 2nd Regiment were across the Quế Sơn Valley and had seized the hill above Chau Son, thus controlling Route 534 into Hiệp Đức. On 24 January, the Division's attack continued, the objective was the former Firebase O'Connor () on high ground just east of Hiệp Đức. From 2–15 July 1974, Trưởng launched
Operation Quang Trung 3/74, sending the 2nd Regiment, a troop of the 11th Armored Cavalry, a battalion of 105 mm howitzers and a battery each of 155 mm howitzers and 175 mm guns into Tiên Phước District to eliminate elements of the PAVN 2nd Division and local VC main force units still threatening the district. The PAVN were forced to withdraw from Tiên Phước with losses of 315 killed and 150 weapons were captured. Its mission completed, the 2nd Regiment began moving back to Quang Nam on 16 July, but left its 3rd Battalion to assist the RF/PF of Quang Tin Province with local security. ==Organisation==