|335th Radio Research Company
|From Tet 1969 through the month of June, the enemy again tried to sustain an offensive. His inability to do so can be largely attributed to aggressive allied ground operations. Between 23 February and 8 June 1969, a total of 70 significant named ground operations were terminated resulting in heavy enemy loss of life and materiel. The main operations concluded during this period were:
(1). The 3d Marine Division's Operation KENTUCKY aimed at preventing enemy infiltration through the Demilitarized Zone in central Quang Tri Province. Throughout the early part of January 1969, Viet Cong/North Vietnamese Army forces continued to avoid major contacts with Free World Forces. Their continual movement to avoid friendly forces or to search for food and supplies contributed to a decrease in the enemy-initiated ground attacks and attacks-by-fire in Quang Tri Province.
(2). Operation NEVADA EAGLE, initiated on 17 May 1968 in Thua Thien Province, continued in 1969 as the U.S. 101st Airborne Division continued to defeat enemy personnel, and capture rice caches, material, and installations within its large area of operations, where it undertook offensive sweeps along Route 547 and around Song Bo.
(3). Two battalions of the 4th Marine Regiment were engaged in Operation SCOTLAND II. Initiated on 15 April 1968, this multi-battalion search and clear operation was centered in and around Khe Sanh.
(4). The IV Corps Tactical Zone Dry Weather Campaign began on 1 December 1968 in support of the overall mission to prevent Viet Cong units from interfering with pacification efforts. This operation, "Speedy Express," interdicted lines of enemy communication and denied him the use of base areas. In 1969 the 1st Brigade, 9th U.S. Infantry Division continued the operation in Dinh Tuong Province, using its highly successful night ambush tactics while the 2d Brigade continued its mission with the Mobile Riverine Force. Although engagements in Operation SPEEDY EXPRESS were typically small, the 9th Infantry Division fought several sizeable engagements with impressive results.
On 23 February U.S. Navy units and installations at Da Nang, Tan An, Ben Luc, Go Dan Ha, and Tra Cu came under numerous and widespread attacks associated with a new enemy offensive, but since many units in these areas were poised to meet these attacks they caused only minimal damage. April saw the heaviest cumulative enemy activity in the barrier interdiction camapign to date.
Consolidation I, 1 July 1971 - 30 November 1971. This period witnessed additional progress in the Vietnamization program which included turning over the ground war to South Vietnam, sustaining the withdrawal of U.S. troops, but also continuing, U.S. air strikes on enemy targets.
South Vietnam assumed full control of defense for the area immediately below the demilitarized zone on 11 July, a process begun in 1969. Secretary of Defense Melvin R. Laird announced completion of Phase I of Vietnamization on 11 August which meant that the U.S. relinquished all ground combat responsibilities to the Republic of Vietnam. The participation of U.S. forces in ground combat operations had not ceased, however, U.S. maneuver battalions were still conducting missions, and the 101st Airborne Division joined the 1st Army of Vietnam 1st Infantry Division in Operation JEFFERSON GLEN that took place in Thua Thien Province in October. This was the last major combat operation in Vietnam which involved U.S. ground forces. Following the close of Operation JEFFERSON GLEN on 8 October, the 101st began stand-down procedures and was the last U.S. division to leave Vietnam.
U.S. troop strengths decreased during Consolidation I. American battle deaths for July 1971 were 66, the lowest monthly figure since May 1967. By early November, U.S. troop totals dropped to 191,000, the lowest level since December 1965. In early November, President Nixon announced that American troops had reverted to a defensive role in Vietnam.
Consolidation II, 1 December 1971 - 29 March 1972. The U.S. continued to reduce its ground presence in South Vietnam during late 1971 and early 1972, but American air attacks increased while both sides exchanged peace proposals.
In early January 1972 President Nixon confirmed that U.S. troop withdrawals would continue but promised that a force of 25,000-30,000 would remain in Vietnam until all American prisoners of war were released. Secretary of Defense Laird reported that Vietnamization was progressing well and that U.S. troops would not be reintroduced into Vietnam even in a military emergency. U.S. troop strength in Vietnam dropped to 136,500 by 31 January 1972, to 119,600 by 29 February, and then to 95,500 by the end of March.
During the last week of December 1971 U.S. Air Force and Navy planes carried out 1,000 strikes on North Vietnam, the heaviest U.S. air attacks since November 1968. Allied commanders insisted that it was necessary because of a huge buildup of military supplies in North Vietnam for possible offensive operations against South Vietnam and Cambodia. Stepped up North Vietnamese anti-aircraft and missile attacks on U.S. aircraft that bombed the Ho Chi Minh Trail in Laos also contributed to the decision. During January 1972 American planes maintained their intermittent bombardment of missile sites in North Vietnam and on he Laotian border and also struck North Vietnamese troop concentrations in the Central Highlands of South Vietnam.
On 25 January President Nixon announced an eight part program to end the war which included agreement to remove all U.S. and foreign allied troops from Vietnam no later than six months after a peace agreement was reached. The North Vietnamese and Viet Cong delegates rejected the proposal and insisted upon complete withdrawal of all foreign troops from Indochina and cessation of all forms of U.S. aid to South Vietnam.
Cease-Fire, 30 March 1972 - 28 January 1973. On 30 March 1972 the North Vietnamese Army launched its greatest offensive of the entire war. The enemy deployed the greatest array of troops and modern weapons to date in a major effort to end the war with conventional forces and seized considerable territory in an effort to exercise control of key provinces throughout Vietnam.
During this critical period the Vietnamization program continued in the face of the North Vietnamese invasion and the successful counterattack by the armed forces of the Republic of Vietnam. Army aviation units played an impressive role throughout the period, flying reconnaissance, close support missions, and transporting troops. As U.S. combat troops were withdrawn from Vietnam, the role of helicopter units increased in importance and they responded to the challenge of continuing to support while preparing the RVNAF to assume their function. Similarly, advisors of all services contributed immeasurably to the defeat of the enemy invasion and the continued Vietnamization process. Army and Marine advisors fought side-by-side with their RVNAF counterparts to stop and defeat the enemy invasion, as the Vietnamese counteroffensive gained momentum and the reduction of field advisers continued. The advisory effort shifted to emphasize training and to assure that the VNAF attained self-sufficiency prior to the complete withdrawal of the U.S forces.
Recapture of Quang Tri City on 16 September 1972 marked the complete failure of the enemy to hold any of the targeted provincial capitols. Massive aid replaced materiel lost during the spring counteroffensive. Retraining and reconstruction of selected RVNAF units increased their capabilities. The completion of the massive logistical buildup of RVNAF was accomplished, which enabled the RVNAF to become more self-sufficient as direct U.S. participation diminished. The US ground role in Vietnam was totally replaced by the RVNAF. During December 1972 and January 1973 the RVIVAF flew more than 45% of air sorties within Vietnam. In November 1972, the RVNAF began a C-130 training program and by January 1973 realized a significant increase in their capability. RVNAF forward air controllers began directing USAF and RVNAF strike aircraft in January 1973. The US policy of Vietnamization continued.
US combat and combat support operations were conducted in support of RVNAF ground operations during the North Vietnamese invasion and the counteroffensive including intensive interdiction of enemy supply routes into Vietnam. Since US ground forces had been reduced to seven battalions, the US ground combat role was limited to defense of key installations. Further reduction in troop ceilings led to the redeployment of all US ground combat battalions, leaving an Army contingent of combat support and service support units.