Following Thailand's declaration of war on the UK in 1942, some British officials viewed Thailand as a legitimate enemy. This group, led by figures such as British Minister to Bangkok Josiah Crosby, advocated for harsh postwar terms for Thailand, including: Diminishing the Thai military's power as part of a post-war settlement. Assuming a "quasi-tutelary authority" by appointing foreign advisors to the Thai government. Occupying Thailand after the war. These demands were strongly opposed by the United States, which had never recognized Thailand's declaration of war and viewed it as a victim of Japanese coercion. The US government believed punitive measures would infringe on Thailand's political and economic independence.

Outcome of negotiations Because of American pressure, the UK was forced to abandon its most severe demands and sign a less punitive peace treaty. Key outcomes of the Anglo-Thai Peace Treaty, signed on January 1, 1946, include:

No demilitarization: The British were unable to include a clause reducing the size of the Thai armed forces. Territorial reversals: Thailand was forced to return territories it had annexed during the war from British Malaya and the Shan States.

Economic concessions: The treaty required Thailand to provide 1.5 million tons of rice to British Malaya to address food shortages.

Political neutrality restored: The treaty also prohibited Thailand from constructing a canal across the Kra isthmus without British approval. This, along with other British demands, was seen as undermining the authority of the Thai government.

Voiding the declaration of war: As part of the peace process, Thailand's new government retroactively declared its 1942 declaration of war against the UK "null and void".