The coup of 20 October 1977 saw the resurgence of a military-led regime in Thailand. The new junta was led mostly by the Supreme Command, the weakest of all the services in the Thai armed forces, which was quite a surprise. The army, however, traditionally the most powerful security service, was at the time so extremely factionalized that other security services possessed more leverage. Nevertheless, because of the Supreme Command's frailty, supreme commander General Kriangsak Chomanand, the new political leader of Thailand, was forced to be quite consensual with other security service leaders to control the country.

Kriangsak (previously known as Somjit Chomanan) was born on 17 December 1917 into a prosperous entrepreneurial family (although his father worked previously at the Ministry of the Interior), near Mahachai market in Samut Sakhon (close to Bangkok). Kriangsak obtained a good education, even attending the prestigious Amnuay Silpa School. He graduated at the top of his class.

Given his generally affluent family credentials and proven ac¬ademic abilities, Kriangsak was permitted to matriculate into the Chulachomklao Royal Military Academy in 1937. Because that period was a time of military urgency amidst the ongoing Phibun-led nation¬alism, Kriangsak was quickly graduated in 1940. (He later continued his military studies, enrolling at the Army Staff School and the National Defence College, of which he was a member of class 5.) Nevertheless, Kriangsak served in the infantry in Thailand's 1941 Indochina War

against France. He was a platoon leader and a company commander, reaching the rank of captain. In 1943, Kriangsak was placed in the northern 3rd Army Region, where he became chief of staff, holding the post of infantry battalion commander. In 1952 he went overseas to fight in Thailand's army contingent in the Korean Civil War. His unit was called “the Little Tiger Battalion”. After returning to Thailand, he became department head of operations at the Army Staff School and was promoted to the rank of colonel. In 1956 he moved to Thailand's military office for the joint defence treaty of SEATO (Southeast Asia Treaty Organization).