In September 1966, the WPK changed its name to the Communist Party of Kampuchea (CPK). The change in the name of the party was a closely guarded secret. Lower ranking members of the party and even the Vietnamese were not told of it and neither was the membership until many years later. The party leadership endorsed armed struggle against the government, then led by Sihanouk. In 1968, the Khmer Rouge was officially formed, and its forces launched a national insurgency across Cambodia. Though North Vietnam had not been informed of the decision, its forces provided shelter and weapons to the Khmer Rouge after the insurgency started. Vietnamese support for the insurgency made it impossible for the Cambodian military to effectively counter it. For the next two years, the insurgency grew as Sihanouk did very little to stop it. As the insurgency grew stronger, the party finally openly declared itself to be the Communist Party of Kampuchea.