In June 1978, Vietnam became the 10th member of COMECON, an organisation established in January 1949 to facilitate and coordinate the economic development of the Eastern Bloc countries belonging to the Soviet Union.
Vietnam’s accession to the organisation
As a result, relations between China, a long time supporter of Vietnam during the First Indochina War and the Second Indochina War, and Vietnam began to deteriorate soon after. China received Vietnam’s membership in COMECON as well as a treaty of friendship signed with the Soviet Union with caution, considering Vietnam’s strengthening ties to the Soviet Union a threat to China’s regional sphere of influence. By 1978, China had ended its aid to Vietnam.