Note 2-F — CHAPTER 2 The Formative Years Military Assistance Advisory Group, Vietnam—Origins of U.S. Marine Assistance—Political Stabilization and Its Effects—Reorganization and Progress—Summing Up Developments

Some sources contend that remnants of the Hoa Hao and Cao Dai armies survived to operate alongside the Viet Cong guerrillas who began threatening the Diem government in the late 1950s. (Kahin and Lewis, The U.S. in Vietnam, p. 111.)