NADK was formed in December 1979 in order to replace the Revolutionary Army of Kampuchea. NADK forces consisted mainly of former RAK troops - large numbers of whom had escaped the 1978 to 1979 Vietnamese invasion of Cambodia. It included as well as conscripts coerced into submission during the RAK retreat and new volunteers or recruits either pressed into service during in-country raids or drawn from among refugee groups. The New York Times reported in June 1987 that "the Khmer Rouge army is believed to be having some success in its recruitment, not only among the refugees in its camps but within the Vietnamese controlled People's Republic of Kampuchea." The NADK did not make personnel figures public, but estimates by military observers and by journalists generally ranged between 40,000 an