<P> The concept of Regional and Popular Forces is in - line with countering the Local Force and Main Force structure of the Viet Cong as they lacked firepower support, while the ARVN Regular Forces fought the PAVN . Local militia came to play a very effective role in the war, as the style of small - unit warfare was better suited for guerrilla conflicts with most more familiar with the region and terrain . Despite being poorly paid, these forces were much more capable at detecting infiltration and holding civilian areas . Accounting for an estimated 2 - 5% of war budget, they were thought to have accounted for roughly 30% of casualties inflicted upon VC / NVA throughout the entire war . Part of this derives in these units generally being more capable of engaging in small - unit, highly - mobile tactics which proved difficult for slow - moving equipment - heavy units . </P> <P> During the early 1960s the Regional Forces manned the country - wide outpost system and defended critical points, such as bridges and ferries . There were some 9,000 such positions, half of them in the Mekong Delta region . </P> <P> Regional Forces played a key role in regional security in the early phase of the war, and while RF / PF members were marginalised and side - lined during the American - intervention as Regular Force Army of the Republic of Vietnam Units were relegated to guarding bases and areas, badly affecting morale and purpose . When U.S. forces began to withdraw from South Vietnam during 1969 and the ARVN began the task of fighting the communist main force units, Regional Forces took on a new importance . For the first time, they were deployed outside their home areas and were sometimes attached to ARVN units . By 1973 the Regional Forces had grown to 1,810 companies, some of which were consolidated into battalions . Charged primarily with local defense under provincial government control, they were too lightly armed and equipped, marginally trained, and lacked the unit cohesion to withstand attack by regular People's Army of Vietnam units supported by tanks and artillery . Most forces were easily subdued, retreated or were destroyed during the Easter Offensive . </P>

Who took on the task of training the south vietnamese army