Final answer:
Thailand, formerly known as Siam, was the only country in Southeast Asia that was never colonized, maintaining its sovereignty by serving as a buffer state between British Burma and French Indochina.
Step-by-step explanation:
Thailand was never colonized. It served as a buffer state between British Burma and French Indochina. During the colonial era where European powers colonized much of Southeast Asia, these powers carved out their spheres of influence on the mainland, with Britain taking control of Burma and France colonizing what was then known as French Indochina, encompassing modern-day Vietnam, Laos, and Cambodia.
The region of Southeast Asia is geographically divided into the mainland and the insular region. Thailand (formerly known as Siam), strategically located on the mainland, adeptly managed to maintain its sovereignty during the colonial period. The monarchs of Thailand skillfully negotiated with both Britain and France, preserving their country's independence by playing these colonial powers against each other. This delicate balancing act allowed Thailand to remain the only country in the region not to fall under European colonial rule.
Burma, by contrast, was brought under British rule and became part of the British Empire in South Asia. The country experienced significant changes under British colonial administration, and Burma's subsequent history was marked by periods of democratic rule, Japanese occupation, and military dictatorship, with a strong influence of the Burmese Way of Socialism and Buddhism in its governance.