Son Sann
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 In 1989, Vietnamese forces were withdrawn from Cambodia, after having successfully quelled the uprising by Khmer Rouge and KPNLF insurgents.