Ho implemented the decision slowly. In January, orders went out to make South Vietnam's central highlands "a base for the revolution." In early May 1959, work started on the Ho Chi Minh trail. By the end of the year, Muoi Cue had left Phnom Penh for War Zone C in South Vietnam. On his arrival in the zone, he doffed his deputy hat, and became chief of Nam Bo. Shortly thereafter, Nam Bo -- with some modifications — became the Central Office of South Vietnam (COSVN).