Franco-Thai War of 1940-1941: Vichy France's Proxy War in Southeastern Asia

Vichy France's "small war" with Thailand in 1940-1941 is one of the most unique campaigns and micro conflicts in the greater military history of World War Two (1939-1945).

Marshall Pétains shakes Adolph Hitler's hand, 1941

The Vichy collaborators in France and abroad formed a coalition/puppet government with their conquerors in the North of France while a 'free' southern zone was established rule by Vichy following the defeat of the French Army and the capture of Paris. The Vichy army fought rather poorly against their former Allies in North Africa while helping to cement fascist rule throughout occupied metropolitan France and Algeria.

Thousands of miles away in French Indochina where French rule had been established by imperial conquest beginning in 1862 as French Cochinchina (Vietnam), the Vichy government collaborated nominally with the Japanese in fear of being ousted by the Imperial Japanese Army (IJA) forces who were already poised to invade the region beginning in 1941-1942. The Vichy had around 35-40,000 soldiers in Southeastern Asia, of which less than 12,000 were Frenchmen or Europeans.

General Phibun (center) posing with his generals and a captured French Foreign Legion standard sometime in 1941

Thailand had become sort of regional power in this period and its alliance with Japan was cemented through recognition of the puppet state of Manchukuo in China and their role as an official Axis power began with them allowing the Japanese through Thailand, and later into Malaya and Singapore in a rout of the British and Commonwealth forces during the opening of the Pacific War. Plaek Phibunsongkhram or simply, Phibun (b.1897-1964), Field Marshall of the Royal Thai military and Prime minister. A long reigning autocrat and dictator, he emerged from the 1930’s as a ruthless military leader of a modernizing Thailand-slowly moving away from the total rule of the old monarchy.

In the Franco-Thai War of 1940-1941 the Vichy French military forces were decisively defeated in every battle or action they fought during the greater land campaign of the conflict. Through the overwhelming combined arms (infantry, mechanized, aerial) assaults of the Royal Thai military, Thailand (Siam) won a total victory. The initial Thai offensive began in January 1941 with a large combined arms assault against French colonial positions in Laos and Cambodia.

Thai Vickers tank crew during the Franco-Thai War

Aerial warfare played a significant part in the conflict overall as the Siamese bombed French positions heavily during the daytime whilst Vichy planes ran nightly sorties against their enemies camps and troop formations with great success. Plane to plane aerial combat (dogfights) were fought as well where the Thai airmen seem to of had more success generally. The French were cut off logistically and many colonial regiments fielded outdated equipment & weapons from the First World War and probably even the late colonial period of the 1890's as well. 

      
French Foreign Legionnaires of the 5th Régiment (Etranger, 5e RE) during the 1941 war

Siamese military forces outnumbered the Vichy forces and fielded armor (the French had none), more artillery, and better and many more warplanes and bombers which had been made in both America by the Vought company and in Japan by Mitsubishi. They had purchased Vickers 6-Ton and Mark 'E' Tanks from England and used them to defeat the shoddily equipped Vichy forces. 

Heavy fighting occurred in the Battambang Province in what is today Cambodia. The most notable action was fought at Yang Dam Koum where the French Division de Cochinchine-Cambodge (RC 1) and Cambodian Tirailleurs Regiment (RTC) were driven from the town after heavy fighting against the Thai assault. This French force was only saved from annihilation when a Legionnaire regiment reinforced their positions. Using 75mm 'flak' artillery guns they destroyed several Siamese tanks, halting the advance of the Thai army in the province for a time.

Vichy French POW's before May 1941

Battle of Koh Chang, January 1941

Knowing that they had to pressure the Thai from the sea, the Vichy French scored a small but nevertheless significant victory over the Royal Thai Navy at the Battle of Koh Chang, 16-17 January 1941. Remnants of the Marine Indochine formed into a Vichy French naval task force of gunboats-consisting of the light cruiser Lamotte-Piquet, the Dumont d’UrvilleAmiral Charner, and the World War I/inter-war era gunboats Tahure and Marne.

French reconnaissance seaplanes spotted a Thai naval force comprised of the ships, the HTMS ThonburiChon Buri (Donburri), and Sri Ayuthia, and the torpedo boats Cholbury, Songkhla, and Trat anchored near the Koh Chang Islands off the southeastern coast of Thailand. The Vichy French task force sought out and opened fire on the Siamese warships who held fast. The battle lasted nearly two hours and was fought in relatively shallow waters for such large ships. Though both sides sustained heavy damage and significant losses, the Thai force was crippled. The Chon Buri, Cholbury, and Songkhla were all sunk and the flagship cruiser, HTMS Thonburi was later wrecked after being badly damaged in Battle of Koh Chang.

HTMS Thonburi in action against the Vichy French Navy on January 17th, 1941

Several nights after the Battle of Koh Chang a Vichy propaganda broadcast from Saigon acknowledged the battle and the Thai navy stating, "...we cannot forget to pay tribute to the fierce and brave fighting of the Thai Naval forces. We wish to pay respect to those who lost their lives in the battle. They died with honor and military pride for their homeland. "

The Franco-Thai War ended following a Japanese mediated ceasefire at Saigon in which the Vichy Regime in Indochina was forced to make almost full territorial concessions to Thailand prepping the region for the forthcoming Japanese invasion. Many Vietnamese would not forget Japan's treachery or France's obvious vulnerabilities in the aftermath of the Franco-Thai conflict leading to the both First and Second Indochina Wars from 1946-1975.

French colonial troops in Cambodia, 1941