 Diệm faced challenges to his authority from four more groups . The Hòa Hảo and Cao Đài religious sects had private armies that controlled the Mekong Delta and the areas west of Saigon , respectively . The Bình Xuyên was an armed , organised crime empire that controlled much of Saigon with a 40 @,@ 000 strong private army , while the Vietminh still controlled much of the rural area . Diệm 's Vietnamese National Army ( VNA ) was led by General Nguyễn Văn Hinh , a French citizen who loathed and frequently disobeyed him . Bảo Đại sold the operating license of the national police to the Bình Xuyên , effectively putting administrative control of the police in the hands of a crime syndicate . 
