In Bangkok, on 3 April 1946, Australia and Siam (Thailand) sign the Final Peace Agreement Between the Government of Australia and the Government of Siam (Australian–Thai Peace Treaty). It is one of the first expressions of Australian sovereignty in foreign affairs after the Statute of Westminster took effect in 1942.

Thailand, allied with Japan from December 1941, declares war on Britain and the United States on 25 January 1942; Canberra, with no legation in Bangkok, notifies via Switzerland on 2 March that it is at war with Siam. Many Australian prisoners die on the Burma–Thailand railway.

After the war the Chifley government sends Lieutenant-Colonel Allan J. Eastman to Bangkok. The British suggest a separate Australian treaty. Canberra’s terms: Thailand end the state of war with London, accept British peace terms, try collaborators and pay reparations for tin mines.

After the Anglo–Thai Peace Treaty of 1 January 1946, Eastman exchanges notes with Prince Vivadhanajaya Jayanta for the 3 April signature. Ratifications are exchanged in May; Eastman stays until then for compensation claims.

In 1950 Thailand pays £6 million to Britain and Australia for mining damage; Australia’s share exceeds £1 million.

The Australian–Thai Peace Treaty of 3 April 1946 remains the instrument that formally closed the war between Canberra and Bangkok and marked independent Australian postwar diplomacy.

Image: Bangkok; Wikimedia Commons. Cropped to 16:9.

Source consulted: Australian–Thai Peace Treaty. Treaty text: An Uneasy Peace… (Australian Journal of International Affairs / Battersby).