Surprised and delighted by Diem’s success, American economic and military aid continued to pour into South Vietnam. In contrast, American military and police advisers helped train and equip Diem’s army and security forces. However, Diem was a poor administrator who refused to delegate authority. By 1957 the communists, now called the Viet Cong (VC), started a program of assassination against government functionaries. In 1960, the communists in the South formed the National Liberation Front (NLF), as the political arm of the Viet Cong and organization for anyone who wanted to put an end to the Diem regime. The Front’s regular army, typically referred to as the “main force” by the Americans, was much smaller than Diem’s army. Still, it was only one segment of the Viet Cong’s so-called People’s Liberation Armed Forces (PLAF).
As the base of the PLAF served village guerrilla units, that consisted of part-time combatants whose function was to persuade their neighbors into supporting the NLF, to defend its political apparatus, and to harass the security forces and the government with kidnappings, raids, and murders. Above the guerrillas were the regional or local authorities, full-time soldiers who operated within the bounds of a region or province. Experienced members of the guerrilla army could be upgraded to the regional or central forces. Based in remote jungles, or mountainous areas, they could operate throughout a province or even the country. When necessary, the full-time forces might also strengthen a guerrilla unit or several units for some particular operation.