| Franco-Thai War | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Part of the aftermath of theJapanese invasion of French Indochina, theSouth-East Asian theatre of World War II and thePacific Theater ofWorld War II | |||||||||
 Plaek Phibunsongkhram observing a captured flag of theForeign Infantry Regiment, after defeating them at the battle of Phum Preav. | |||||||||
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| Belligerents | |||||||||
Supported by: Japan | |||||||||
| Commanders and leaders | |||||||||
 Jean Decoux |  Plaek Phibunsongkhram | ||||||||
| Strength | |||||||||
| 50,000 men (38,000 colonials) 20 light tanks 100 aircraft 1 light cruiser 4 avisos | 60,000 men 134 tanks 140 aircraft[5] 3 coastal defense ships 12 torpedo boats 4 submarines | ||||||||
| Casualties and losses | |||||||||
| Land: 321 killed or wounded 178 missing 222 captured 22 aircraft destroyed Sea: 11 killed[6][7] Total: 721+ casualties | Land: 54 killed[8] 307 wounded 21 captured 8–13 aircraft destroyed Sea: 36 killed[6][7] 3 torpedo boats sunk[6] 1 coastal defense ship grounded Total: 418[6][7] casualties | ||||||||
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TheFranco-Thai War (October 1940 – 28 January 1941,Thai:กรณีพิพาทอินโดจีน,romanized: Karani Phiphat Indochin;French:Guerre franco-thaïlandaise) was fought betweenThailand andVichy France over certain areas ofFrench Indochina.
Negotiations shortly beforeWorld War II had shown that the French government was willing to alter the boundaries between Thailand and French Indochina, but only slightly. Following theFall of France in 1940, Major-GeneralPlaek Phibunsongkhram (popularly known as "Phibun"), the prime minister of Thailand, decided that France's defeat strengthened the Thais' negotiating position to regain the vassal stateterritories that were ceded to France during KingChulalongkorn's reign.
The German and Italian military occupation ofMetropolitan France rendered France's hold on French Indochina and its other overseas territories tenuous. The colonial administration was cut off from outside help and supplies. After theinvasion of French Indochina in September 1940, Japan forced the French to allow them to set up military bases. The French's seemingly subservient behavior lulled the Phibun regime into believing that France would not seriously resist a military confrontation by Thailand.
The French military forces in Indochina consisted of an army of approximately 50,000 men, 12,000 of whom were French, organized into forty-oneinfantrybattalions, twoartilleryregiments, and a battalion ofengineers.[9] TheVichy French Army had a shortage ofarmor, and it could field only 20Renault FTtanks against the nearly one hundredRoyal Thai Army armored vehicles. The bulk of the French forces stationed near the Thai borderconsisted of the Indochinese infantry of the 3rd and 4th Regiments ofTonkinese Rifles (Tirailleurs Tonkinois), together with a battalion ofMontagnards (indigenousVietnamese highlanders), French regulars of the Colonial Infantry (Troupes coloniales), andFrench Foreign Legion units.[10]
TheVichy French Navy had thelight cruiserLamotte-Picquet and fouravisos in French Indochina.
TheVichy French Air Force (Armée de l'Air) had approximately 100 aircraft, of which roughly 60 could be considered front-line. These included thirtyPotez 25 TOEreconnaissance/fighter-bombers, fourFarman 221 heavybombers, sixPotez 542 bombers, nineMorane-Saulnier M.S.406fighters, and eightLoire 130 reconnaissance/bomberflying boats.[11]
The slightly larger Thai Army was a relatively well-equipped force.[12] Consisting of 60,000 men, it was made up of fourarmies. The largest were the "Burapha Army" with fivedivisions and the "Isan Army" with three divisions. Independent formations under direct control of the army high command included two motorizedcavalry battalions, one artillery battalion, onesignals battalion, one engineer battalion, and one armored regiment. The artillery was a mixture ofKrupp guns and modernBofors guns andhowitzers, while 60Carden Loyd tankettes and 30Vickers 6-ton tanks made up the bulk of the army's tank force.
TheRoyal Thai Navy included twoThonburi-classcoastal defense ships, 12torpedo boats, and four Japanese-madesubmarines.[13] The Royal Thai Navy was inferior to the French naval forces inSoutheast Asia, but theRoyal Thai Air Force held both a quantitative and qualitative edge over the localArmée de l'Air units.[13] Among the 140 aircraft that composed theRoyal Thai Air Force's first-line strength were 24Mitsubishi Ki-30 light bombers, nineMitsubishi Ki-21 heavy bombers, 25Curtiss Hawk 75N fighter planes, sixMartin B-10 medium bombers, and 70Vought O2U Corsairobservation/attack aircraft.[5]
While nationalist demonstrations and anti-French rallies were being held inBangkok, several border skirmishes erupted along theMekong frontier. The superior Royal Thai Air Force then conducted daytime bombing runs over military targets inVientiane,Phnom Penh,Sisophon, andBattambang with impunity. The French retaliated with their own air attacks, but the damage they caused was less than equal. The activities of the Thai air force, particularly in the field of dive-bombing,[13] was such that AdmiralJean Decoux, the governor of French Indochina, grudgingly remarked that the Thai planes seemed to have been flown by men with plenty of war experience.[14]
On 5 January 1941, following the report of a French attack on the Thai border town ofAranyaprathet, the Thai Burapha and Isan Armies launched an offensive onLaos andCambodia. French response was instantaneous, but many units were simply swept aside by the better-equipped Thai forces. The Thai army swiftly overranLaos, but the French forces inCambodia managed to rally and offer more resistance.[15]
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At dawn on 16 January, the French launched a large counterattack on the Thai-held villages of Yang Dang Khum and Phum Preav, initiating the fiercest battle of the war. Due to poor coordination and nonexistent intelligence against the entrenched and well-prepared Thai forces, the French operation was stopped and fighting ended with a French retreat from the area. However, the Thais were unable to pursue the retreating French, as their forward tanks were kept in check by the gunnery ofFrench Foreign Legion artillery.
With the situation on land rapidly deteriorating for the French, Admiral Decoux ordered all available French naval forces into action in theGulf of Thailand. In the early morning of 17 January, a French naval squadron caught a Thai naval detachment by surprise at anchor offKo Chang island. The subsequentBattle of Ko Chang was a tactical victory for the French and resulted in the sinking of two Thai torpedo boats and the disabling of a coastal defense ship, with the French suffering no casualties.[7] Fearing the war would turn in France's favor, the Japanese intervened, proposing an armistice be signed.
On 24 January, the final air battle took place when Thai bombers raided the French airfield atAngkor, nearSiem Reap. The last Thai mission bombing Phnom Penh commenced at 07:10 on 28 January, when the Martins of the 50th Bomber Squadron set out on a raid on Sisophon, escorted by thirteenHawk 75Ns of the 60th Fighter Squadron.[5][11]
Japan subsequently stepped in to mediate the conflict. A general ceasefire had been arranged to go into effect at 10:00 on 28 January, and a Japanese-sponsored "Conference for the Cessation of Hostilities" was held at Saigon, with preliminary documents for an armistice between the governments of MarshalPhilippe Pétain's French State and the Kingdom of Thailand signed aboard the cruiserNatori on 31 January 1941. On 9 May, a peace treaty was signed inTokyo,[12][13] with the French being coerced by the Japanese to relinquish their hold on the disputed border territories. France ceded the following provinces to Thailand fromCambodia andLaos:
The resolution of the conflict was widely acclaimed by the people of Thailand, and was seen as a personal triumph for Phibun. For the first time in its history, Thailand had been able to extract concessions from a European power, albeit a weakened one. For the French inFrench Indochina, the conflict was a bitter reminder of their isolation after theFall of France. They felt that an ambitious neighbor had taken advantage of a distant colony being cut off from a weakened parent. Without hope of reinforcements, the French had little chance of offering a sustained resistance.
To commemorate the victory, Phibun erected theVictory Monument in Bangkok. Thailand invited Japan and Germany to join in the celebration of its construction.
The Japanese wanted to maintain both their working relationship withVichy and the status quo; therefore, the Thais were forced to accept only a quarter of the territory that they gained from the French, in addition to having to pay six millionpiastres as a concession to the French.
However, the real beneficiaries of the conflict were the Japanese, who were able to expand their influence in both Thailand and Indochina. The Japanese wanted to use Thailand and Indochina as their military bases to invadeBritish Burma andBritish Malaya later. The Japanese won from Phibun a secret oral promise to support them in an attack on Malaya and Burma.Phibun did not keep his word.[16]
Relations between Japan and Thailand were subsequently stressed, as a disappointed Phibun switched to courting the British and Americans to ward off what he saw as an imminent Japanese invasion.[17] However, on 8 December 1941, the Japaneseinvaded Thailand at the same time as theJapanese invasion of Malaya. Pearl Harbor was attacked one-and-a-half hours after Malaya and Thailand were. Fighting between Japanese and Thai forces lasted only five hours before a ceasefire was agreed. Thailand would beallied with Japan until 1945.
After the war, in October 1946, northwestern Cambodia and the two Lao enclaves on the Thai side of theMekong River were returned to French sovereignty when theFrench provisional government threatened to veto Thailand's membership in theUnited Nations.[18] This led to the conclusion of theFranco-Siamese Settlement Treaty of 1946 that settled the issue and paved the way to restoration of diplomatic relations between the two countries.
The French army suffered a total of 321 casualties, of whom 15 were officers. The total number of missing after 28 January was 178 (six officers, 14 non-commissioned officers and 158 enlisted men).[12] The Thais had captured 222 men (17 North Africans, 80 Frenchmen, and 125 Indochinese).[5]
The Thai army suffered 54 men killed in action and 307 wounded.[8] 41 sailors and marines of the Thai navy were killed, and 67 wounded. At theBattle of Ko Chang, 36 men were killed, of whom 20 belonged toHTMSThonburi, 14 to HTMSSongkhla, and two toHTMSChonburi. The Thai air force lost 13 men. The number of Thai military personnel captured by the French was just 21.
About 30 percent of the French aircraft were rendered unserviceable by the end of the war, some as a result of minor damage sustained in air raids that remained unrepaired.[13] The Armée de l'Air admitted the loss of one Farman F221 and two Morane M.S.406s destroyed on the ground, but its losses were really greater.[11]
In its first experience of combat, the Royal Thai Air Force claimed to have shot down five French aircraft and destroyed 17 on the ground, against the loss of three of its own in the air and another five to 10 destroyed in French air raids on Thai airfields.
