Under the 1963 constitution, Massamba-Débat was elected president for a five-year term. During Massamba-Débat's term in office, the regime adopted "scientific socialism" as the country's constitutional ideology. In 1965, Congo established relations with the Soviet Union, the People's Republic of China, North Korea, and North Vietnam. On the night of February 14 to 15, 1965, three prominent public officials of the Republic of the Congo were kidnapped:  (prosecutor of the Republic),  (President of the Supreme Court), and  (director of the Congolese Information Agency). The bodies of two of these men were later found, mutilated, by the Congo River. Massamba-Débat's regime also invited several hundred Cuban army troops into the country to train his party's militia units. These troops helped his government survive a ''coup d'état'' in 1966 led by paratroopers loyal to future President Marien Ngouabi. Nevertheless, Massamba-Débat was unable to reconcile various institutional, tribal, and ideological factions within the country, and his regime ended abruptly with a bloodless ''coup'' in September 1968.