After the People's Army of Vietnam and Cambodian troops overthrew the Pol Pot regime in the 1979 Cambodia-Vietnam Border War, the Khmer Rouge remnants fled westward to the border areas near Thailand. With Chinese support, the Khmer Rouge remnants regrouped and reorganized in the jungles and mountains of the Thai-Cambodian border. In their efforts to eliminate the Khmer Rouge, Vietnamese troops advanced close to and even crossed the Thai border to attack Khmer Rouge bases. The tensions sparked a series of sporadic clashes and confrontations that, although never formally declared, lasted until Vietnam withdrew from Cambodia in 1989.
