History of Thailand since 1973:A return to military rule

By late 1976 moderate middle class opinion had turned away from radicalism as the students, with their base at Thammasat University, grew more militant. The army and the right-wing parties fought back against the radicals through paramilitary groups such as the Village Scouts and the Red Gaurs. Matters came to a head in October when Thanom returned to Thailand to enter a monastery. Violent student protests were met by equally violent counter-protests. On October 6, 1976 the army unleashed the paramilitaries, and used the resultant orgy of violence, in which hundreds of students were tortured and killed, to suspend the constitution and resume power.

The army installed Thanin Kraivixien, an ultra-conservative former judge, as prime minister, and carried out a sweeping purge of the universities, the media and the civil service. Thousands of students, intellectuals and other leftists fled Bangkok and joined the Communist Party's insurgent forces in the north and north-east, operating from safe bases in Laos. Others left for exile, including Dr. Puey Ungphakorn, the respected economist and Rector of Thammasat University. The economy was also in serious difficulties, in no part due to Thanin's policies, which frightened foreign investors. The new regime proved as unstable as the democratic experiment had been. In October 1977 the army staged another "coup" and replaced Thanin with General Kriangsak Chomanand.

By this time, Thai forces had to deal with the situation resulting from the Vietnamese invasion of Cambodia. There was another flood of refugees, and both Vietnamese and Khmer Rouge forces periodically crossed into Thai territory, sparking clashes along the borders. A 1979 visit to Beijing earned Deng Xiaoping's agreement to end support for Thailand's communist movement; in return, the Thai authorities agreed to give safe haven to the Khmer Rouge forces fleeing west following the invasion of Cambodia. Revelations of the crimes of the defeated Khmer Rouge also sharply reduced the appeal of communism to the Thai public. Kriangsak's position as prime minister soon became untenable and he was forced to step down in February 1980 at a time of economic troubles. Kriangsak was succeeded by the army commander-in-chief, General Prem Tinsulanonda, a staunch royalist with a reputation for being incorruptible.

References : Thongchai Winichakul. Siam Mapped. University of Hawaii Press, 1984.Wyatt, David. Thailand: A Short History (2nd edition). Yale University Press, 2003.