1957-1963 II Corps headquarters became operational in October 1957 and was responsible for the Central Highlands and the coastal region from southern
Quang Nam province south to the town of
Phan Thiet. II Corps headquarters was originally located at
Ban Me Thuot in the Central Highlands, but was moved to Pleiku in mid-1959. On 24 February 1964 Khánh issued the 1964 National Campaign Plan under the name
Chien Thang (Struggle for Victory). Khanh decided the provinces surrounding Saigon would receive top priority in the distribution of troops, civil servants, and money. The rest of
III Corps and
IV Corps were next in the resource queue, whereas the provinces of II and I Corps had the lowest priority. One reason why the north received the least resources was that, at least before late 1963, it had appeared to be in the best shape. Thus,
Chien Thang forecast that I and II Corps would be the first to enter into the final phase, the destruction of the enemy's last major formations and bases in January 1965, whereas III and IV Corps would not reach that point until January 1966. On 12 July the US 1st Battalion,
18th Infantry Regiment, and an artillery battery disembarked at
Cam Ranh Bay to provide security for the new port being built there. On 17 July the 22nd Division and eight reserve battalions launched Operation
Than Phong to reopen Highway 19 and deliver supplies to Pleiku. Resistance proved light, and after troops had secured Highway 19, vehicles drawn from every possible source delivered 3,000 tons of supplies to Pleiku. From there, aircraft and trucks brought succor to other government-controlled areas. Public confidence in the highlands rose, and food prices dropped by as much as 30 percent. On 29 September the 1st Battalion, 18th Infantry ceded its mission at Cam Ranh to the 1st Brigade, 101st Airborne Division, and rejoined the rest of its regiment at Bien Hoa. In the Combined Campaign Plan for 1966, which the JGS and MACV issued in December, the allies declared their "basic objective" for the year to be clearing, securing, and developing the heavily populated regions around Saigon, in the Mekong Delta, and in selected portions of the I and II Corps coastal plain. "Coincident" with this effort, they would defend significant outlying government and population centers and conduct search and destroy operations against "major VC/PAVN forces." In pursuit of these objectives, South Vietnamese forces would concentrate on defending, clearing, and securing the designated strategic areas. American and third-country forces, besides securing their own bases and helping to protect rice-producing areas, were to "conduct operations outside of the secure areas against VC forces and bases." Implicit in these words was the defacto division of labor between the South Vietnamese and Americans that had been in effect since the summer. From 19-30 June the 1st Cavalry Division conducted
Operation Nathan Hale in western Phú Yên province. From 12 October to 31 January 1969 the 4th Infantry Division and ARVN forces conducted
Operation MacArthur in western Kontum and Pleiku provinces.
1969 In January 1969, Peers and Lan agreed to replace one brigade of the US 4th Division in Kontum Province with the military forces of the ARVN 24th Special Tactical Zone. Peers regarded the zone's organic infantry unit, the (nondivisional) 42nd Regiment, as well led, familiar with the land, and accustomed to using American fire support when needed. Based in a sparsely populated border area, the 42nd had developed a higher degree of combat expertise than its pacification-bound sisters along the coast, and, with II Corps armor and ranger reinforcements, its American advisers felt that the regiment could hold the northern Highlands. The PAVN objective during the
Easter Offensive in II Corps was to seize the cities of Kon Tum and Pleiku, thereby overrunning the Highlands. This would then open the possibility of proceeding east to the coastal plains, splitting South Vietnam in two. The PAVN were under the command of Lieutenant general Hoang Minh Thao, commander of the B-3 Front. The Front included the
320th and 2nd Divisions in the highlands and the 3rd Division in the lowlands – approximately 50,000 men.It had become evident as early as January that the PAVN were building up for offensive operations in the tri-border region and numerous B-52 strikes had been conducted in the area in hopes of slowing the build-up. ARVN forces had also been deployed forward toward the border in order to slow the PAVN advance and allow the application of airpower to deplete North Vietnamese manpower and logistics. The Highlands offensive was preceded by PAVN/VC diversionary operations that opened on 5 April in coastal Bình Định province, which aimed at closing Highway 1, seizing several ARVN firebases, and diverting South Vietnamese forces from operations further west. The 22nd Division was split between the Highlands and the coast, where it still had area security missions, and was more or less chopped up in detail. The division headquarters was overrun at Tan Canh. Du blamed himself for the initial defeats, lost heart, and was replaced by General
Nguyễn Văn Toàn, but CORDS' commander Vann effectively took over the defense of II Corps. Kontum city, key to the Highlands, was defended by a mixed bag of Airborne, Ranger, territorial, and armored forces, and one regiment of the 23rd Division. Colonel
Lý Tòng Bá, the new commander of the 23rd Division was put in charge of the defense, but he found it impossible to control the non-divisional elements supposedly under his command, and Vann himself reported on 2 May that the Airborne and Ranger commanders at Kontum were "in almost open rebellion" and later, on the 8th, noted the start of several Montagnard mutinies. However, the PAVN took their time investing the city, giving the defenders a chance to reorganize. At Vann's suggestion, Toàn replaced the Airborne and Ranger units with the other two regiments of the 23rd, and with his entire division on line, Ba was able to hold out against repeated PAVN attacks supported by US B-52 strikes, tactical air, and helicopter gunships coordinated by Vann and his team. By early June the PAVN were withdrawing back into their border sanctuaries. From 8 June to 16 September in the
Battle of Trung Nghia PAVN forces captured the village of Trung Nghia in the Central Highlands west of Kontum. The PAVN were eventually forced out. On 31 March the PAVN 320th Division had Tuy Hòa under artillery fire. As the PAVN attacked
Phu Cat Air Base the RVNAF flew out about 32 aircraft, leaving about 58, mostly disabled or destroyed, on the ground. From 1-2 April, about 7,000 troops of the 22nd Division and Binh Dinh territorials boarded Navy ships at Qui Nhon and sailed for
Vũng Tàu. On the morning of 2 April Phú met with General Nguyễn Văn Hiếu, the deputy commander of III Corps near Phan Thiết, Hiếu informed Phú that II Corps had been dissolved and the remaining provinces and forces would be incorporated into III Corps. ==Divisions==