National Assembly and most accounts emphasize the primacy of Cambodian actors in Sihanouk's removal. Historians are divided about the extent of U.S. involvement in or foreknowledge of the ouster, but an emerging consensus posits some culpability on the part of U.S. military intelligence. However, according to Ben Kiernan, "There is in fact no evidence of CIA involvement in the 1970 events". 1972 Senator Clifford P. Case sponsored a law effective December 1972 cutting off funds for CIA and private military company operations in Cambodia (see the Case–Church Amendment). 1982 In December 1978, Vietnam invaded Cambodia and overthrew the genocidal Khmer Rouge regime, ending the Cambodian genocide and installing a new government led by Khmer Rouge defectors. The Reagan administration authorized the provision of aid to a coalition called the Khmer People's National Liberation Front (KPNLF), run by Son Sann. In 1989, Vietnamese forces were withdrawn from Cambodia, after having successfully quelled the uprising by Khmer Rouge and KPNLF insurgents. See also CIA activities in Laos Hughes–Ryan Amendment Allegations of United States support for the Khmer Rouge References CIA activities in Asia Political history of Cambodia Cambodia–United States relations Cambodia