1957 Thai coup d'état

1957 Thai coup d'état
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Title	1957 Thai coup d'état
Caption	Military parade in Bangkok, 1957
Date	16 September 1957
Place	Bangkok, Thailand
Type	Military coup
Commanders	Field Marshal Sarit Thanarat; Police General Phao Sriyanond; Prime Minister Plaek Phibunsongkhram
Outcome	Removal of Prime Minister Plaek Phibunsongkhram; military consolidation under Sarit; establishment of junta-led administration

1957 Thai coup d'état was a military overthrow on 16 September 1957 that deposed Prime Minister Plaek Phibunsongkhram and brought Field Marshal Sarit Thanarat and allied officers to power in Bangkok, Thailand. The coup followed factional struggles involving senior figures such as Police General Phao Sriyanond and Prime Minister Plaek’s civilian allies, set against Cold War pressures involving United States security interests in Southeast Asia and destabilizing scandals tied to electoral manipulation and corruption. The event precipitated the end of an era of semi-democratic administrations and ushered in an extended period of military-dominated rule centered on Sarit and his network, reshaping Thai politics through interventions in the Parliament of Thailand, bureaucracy, and royal relations.

Background

By the mid-1950s Thailand's political landscape featured recurring interventions by military leaders drawn from institutions such as the Royal Thai Army, Royal Thai Navy, and Royal Thai Police. Plaek Phibunsongkhram, a veteran of the Siamese Revolution of 1932 and the Franco-Thai War, had regained prominence after World War II and led coalitions involving constituencies in Bangkok and provincial elites. Intense rivalry existed between army factions associated with commanders trained at the Chulachomklao Royal Military Academy and police networks built under Phao Sriyanond, who had ties to business magnates in Bangkok and provincial notables in Isan. Thailand’s alignment with the United States through bilateral security pacts and participation in initiatives like the Southeast Asia Treaty Organization amplified external stakes, while domestic controversies—such as allegations surrounding the 1957 Thai general election and bribery scandals implicating members of Plaek’s circle—heightened elite competition. The monarchy, personified by King Bhumibol Adulyadej, remained a central institutional touchstone around which military leaders sought legitimacy.

Coup plotters and motivations

Primary plotters included Field Marshal Sarit Thanarat, a decorated commander with a power base in the army’s First Division, and allied officers who viewed Plaek’s administration as compromised by corruption and electoral malpractice. Police General Phao Sriyanond and other police elites had earlier supported Plaek but turned increasingly fractious as patronage disputes emerged. Motives combined personal ambition, institutional rivalry between the Royal Thai Army and the Royal Thai Police, concerns about inflation and rural unrest in regions like Chiang Mai and Nakhon Ratchasima, and strategic calculations about Thailand’s posture in the Cold War confrontation with Communist Party of Thailand insurgents and neighboring Laos. Certain civilian figures—members of the Democrat Party and royalist bureaucrats—privately backed intervention to restore order and protect royal prerogatives. International intelligence actors, including elements of the Central Intelligence Agency, monitored developments closely because of Thailand’s role in SEATO and as a staging area for regional operations.

Course of the coup

In mid-September 1957 officers loyal to Sarit and sympathetic commanders moved troops into strategic points in Bangkok, seizing radio stations, the Ministry of Defence (Thailand), and transport hubs such as Don Mueang International Airport. The coup unfolded with coordinated actions against key loyalists of Plaek, including arrests of cabinet ministers and military officers. Plaek initially sought to consolidate power through emergency measures and appeals to the Monarchy of Thailand and parliamentary allies in the House of Representatives of Thailand, but Sarit’s faction rapidly isolated the prime minister politically and physically. Communication channels controlled by the coup leaders broadcast announcements dissolving elements of the sitting administration and appointing caretaker arrangements centered on military figures. The operation emphasized speed and limited bloodshed; clashes occurred in limited instances but widespread urban warfare was avoided through rapid capitulation by many civil servants and police units reluctant to confront army units.

Immediate aftermath and political changes

Following the coup, Sarit installed a junta that suspended parts of the constitution and replaced key ministers with military appointees drawn from the Royal Thai Army high command and sympathetic police officials. Plaek was removed from power and faced political sidelining and later exile; several of his allies were detained by security services under orders from the new regime. The junta moved to reorganize electoral institutions, purge officials seen as corrupt, and reassert control over state enterprises and patronage networks that had previously been influenced by Phao and Plaek supporters. The Parliament of Thailand was curtailed, with the junta issuing decrees to govern and promising a return to stability and anti-corruption measures. Sarit sought legitimacy by cultivating ties with King Bhumibol Adulyadej and by appealing to conservative elites, business leaders in Bangkok, and provincial notables who favored strong leadership.

Domestic and international reactions

Domestic reactions were mixed: royalists and conservative elites welcomed a crackdown on perceived corruption and disorder, while urban intellectuals, student groups in institutions like Chulalongkorn University, and members of the Democrat Party (Thailand) expressed concern about the curtailment of civil liberties and parliamentary rule. Labor organizations and rural movements in provinces such as Ubon Ratchathani registered anxiety over military control of resources. Internationally, the United States Department of State, United Kingdom Foreign Office, and other Western capitals weighed responses in light of Cold War priorities; many diplomats prioritized stability and continuity of Thai support against Communist insurgencies and thus offered guarded acceptance, while leftist governments and regional nationalists criticized the overt military takeover. Intelligence and defense establishments in Washington, D.C. and allied embassies recalibrated cooperation with the new leadership, maintaining ties with Sarit while watching for human rights and political repression developments.

Legacy and historical assessment

The 1957 coup is assessed as a decisive moment that ended a fragile postwar experiment with electoral politics and entrenched military dominance under Sarit’s subsequent rule, affecting institutions including the Thai monarchy, bureaucracy of Thailand, and security apparatus. Historians link the coup to later centralization policies, development projects endorsed by Sarit, and changing patterns of patronage involving business elites in Bangkok and provincial powerbrokers. The event influenced Thailand’s role in regional alignments during crises such as the Laotian Civil War and the broader Vietnam War, while shaping civil-military relations and elite bargains that persisted into later coups in 1976, 1991, and beyond. Scholarly debates consider motives ranging from anti-corruption rhetoric to personalist ambitions and geopolitical calculation, placing the coup within broader patterns of postcolonial state-building and Cold War intervention in Southeast Asia. Category:Coups in Thailand