The main duties of the Special Forces entailed the recruitment and training of one-to-four man teams in intelligence, sabotage, and psychological warfare missions in North Vietnam.

In the autumn of 1961, Special Forces units began Operation Eagle at Bình Hưng with a night parachute assault.

Despite the fact that South Vietnam was struggling against the communist insurgency of the Viet Cong in the rural areas, the Special Forces were mostly kept in the capital Saigon, where they were used to prevent coups or harass regime opponents.

Under Diệm, the Special Forces were headed by Colonel Lê Quang Tung, who had been trained by the CIA in the United States and commanded some 1,840 men under the direction of Nhu.

Tung's most notable military activity was leading a group run by the CIA, in which ARVN personnel of northern origin were sent into North Vietnam, posing as locals, in order to gather intelligence as well as sabotaging communist infrastructure and communications.

With opposition to Diệm growing, Nhu plotted an attack against Xá Lợi Pagoda, the largest Buddhist centre in Saigon, where the movement was organizing its activities.

Tung's Special Forces under Nhu's orders were responsible for the raid on 21 August 1963, in which 1,400 monks were arrested and hundreds were estimated to have been killed, as well as extensive property damage.

As pilgrimages to the pond grew larger and more frequent, so did disquiet among the district chief and his officials, who answered to Ngô Đình Cẩn, another younger brother of Diệm.

Tung was reported to have been planning an operation at the request of Nhu to stage a government organised student demonstration outside the US Embassy, Saigon.

In this plan, Tung and his operatives would assassinate U.S. ambassador Henry Cabot Lodge Jr., other key officials and Buddhist leader Thích Trí Quang, who was given asylum after being targeted in the pagoda raids.

By 1965, LLDB personnel were working with the ARVN in recruiting and training as well as sending groups into communist areas in South Vietnam to gather information.

[citation needed] The LLDB's largest operation occurred with the CIDGs, an immense network of ethnic minorities and Montagnards funded and trained with CIA-U.S. Special Forces resources.

Historically, the South Vietnamese considered such minorities inferior, especially the semi-primitive mountain tribes, and this diminished effective cooperation and a mutual sense of purpose between the LLDB and its Central Highland militia.

Command and control was frequently strained, a factor that contributed to an unsuccessful rebellion in September 1964, by tribal groups loyal to the United Front for the Liberation of Oppressed Races (FULRO).