After the Khmer Rouge regime was overthrown , a new Cambodian government supported by Vietnam , the People 's Republic of Kampuchea ( PRK ) , was established . The Chinese leader , Deng Xiaoping , was unhappy with Vietnam 's influence over the PRK government . Deng proposed to Sihanouk that he co-operate with the Khmer Rouge to overthrow the PRK government , but the latter rejected it , as he opposed the genocidal policies pursued by the Khmer Rouge while they were in power . In March 1981 , Sihanouk established a resistance movement , FUNCINPEC which was complemented by a small resistance army known as Armée Nationale Sihanoukiste ( ANS ) . He appointed In Tam , who had briefly served as Prime Minister in the Khmer Republic , as the commander-in-chief of ANS . The ANS needed military aid from China , and Deng seized the opportunity to sway Sihanouk into collaborating with the Khmer Rouge . Sihanouk reluctantly agreed , and started talks in March 1981 with the Khmer Rouge and the Son Sann-led Khmer People 's National Liberation Front ( KPNLF ) on a unified anti-PRK resistance movement
genocidal policies
Cambodian genocide
Norodom Sihanouk