End of Empire100 days in 1945 that changed Asia and the world.

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  • The lost territories: Franco-Thai relations after WWII

    Shane Strate

    After allying with the Japanese during the war, Thailand’s road to post-war rehabilitation was fraught with complications. Even before Japan’s surrender, Thai leaders began planning reconciliation with Britain and the United States. They failed to anticipate, however, that the primary obstacle to the country’s re-entry into the international community would come from France. In August 1945, French diplomats in Kandy informed their American and Thai counterparts that the new Free French government did not recognize the Tokyo Peace Accord of 1941. For France, this meant that a state of hostilities would continue to exist between itself and Thailand until the ‘lost territories’ were returned to French Indochina.

    The border between France and Thailand had been a constant source of tension since its formalization in 1893. In that year, France dealt Siam an embarrassing military defeat and forced King Chulalongkorn to renounce his claim to territories on the left bank of the Mekong. Succeeding treaties transferred additional Lao and Khmer lands to French Indochina. When the Thai military deposed the absolute monarchy in 1932, the new rulers reformulated Thai nationalism based on principles of ethnic chauvinism and irredentism. The Phibun regime identified the ‘lost territories’ as regions that had been amputated from the body of the Thai nation-state. He argued that its inhabitants were ethnic Thais suffering under French occupation. By 1940, the ‘lost territories’ represented a growing sense of National Humiliation, the idea that Thailand had been bullied by western imperialist powers over the last century. By invading French Indochina in January 1941, Phibun intended to erase this legacy of shame and elevate the military to the role of national saviours. The conflict ended with the Tokyo Peace Accord, where Japanese mediators pressed French Indochina to cede portions of Lao and Khmer territory to Thailand. These annexed regions became the Thai provinces of Lan Chang, Phra Tambong, Nakhon Champassak and Phibun Songkhram. In June 1941, Phibun celebrated his triumph with the construction of a ‘Victory Monument.’

    The acquisition of the ‘lost territories’ was the greatest foreign policy achievement in modern Thai history; but following Japan’s defeat the four provinces represented the country’s biggest political liability. Still smarting from its own wartime humiliation, France’s new government was determined to re-establish its empire in Southeast Asia (see p. 143). It thus demanded the unconditional return of the four provinces ceded in 1941. When the Thai government delayed, France used its seat on the Security Council to block Thailand’s application for membership in the United Nations. As the impasse dragged on into 1946, Thai leaders faced an impossible decision. Keeping the provinces meant exclusion from the United Nations, a critical step in rehabilitating the country’s international standing. Ceding territory, however, would stoke popular outrage at home. Thais were convinced that those lands were ‘Thai’, and blood had been shed to restore them to the nation. Capitulating to France would be considered a shameful act, one that could further de-stabilize the civilian government.

    By 1946, the Thai government’s options had narrowed. The United States and Britain refused to support its claims to the provinces. France had rejected offers to submit the matter to the World Court. Over the summer, the battle for French Indochina spilled across the Mekong into Thailand. France accused Thailand of aiding the Free Lao forces and rumours of a possible French invasion swirled in the Bangkok papers. In October the fate of the four provinces came up for debate in the National Assembly, with several Assemblyman arguing that war with French was preferable to surrendering the provinces and returning its citizens to colonial servitude.

    On 18 October 1946, Prime Minister Thamrong announced his government’s verdict: Thailand would return the four provinces to France. He called the resolution ‘another sad chapter in our nation’s history’, but explained that it was necessary to demonstrate the country’s commitment to peace and to secure membership in the United Nations. The decision to give back the territories helped weaken confidence in civilian rule (and as such was a factor in the military’s return to power in 1947) and led to the Thai–Cambodian dispute over Preah Vihear a decade later.

    Shane Strate is Assistant Professor of History, Kent State University







    0904.9Kandy, Celon,  will be the scene of a series of important meetings in early September 1945 (Germaine Krull)





    0816.1Phibun Songkhram was a leading figure in Thailand's recovery of the 'lost territories' in 1938 – one of which he named after himself. The Field-Marshal's alliance with the Japanese proved to be a temporary post-war liability. Phibun was ousted in 1944 but had returned to power by 1948.


    0827.3Map: Territory ceded to Thailand in 1941–43 (NIAS Press 2016)

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