At the Potsdam Conference in July 1945 , the Combined Chiefs of Staff decided that Indochina south of latitude 16 ° north was to be included in the Southeast Asia Command under British Admiral Mountbatten . Japanese forces located south of that line surrendered to him and those to the north surrendered to Generalissimo Chiang Kai-shek . In September 1945 , Chinese forces entered Tonkin , and a small British task force landed at Saigon . The Chinese accepted the Vietnamese government under Hồ Chí Minh , then in power in Hanoi . The British refused to do likewise in Saigon , and deferred to the French there from the outset , against the ostensible support of the Việt Minh authorities by American OSS representatives . On V-J Day , September 2 , Hồ Chí Minh had proclaimed in Hanoi the establishment of the Democratic Republic of Vietnam ( DRV ) . The DRV ruled as the only civil government in all of Vietnam for a period of about 20 days , after the abdication of Emperor Bảo Đại , who had governed under Japanese rule . On 23 September 1945 , with the knowledge of the British commander in Saigon , French forces overthrew the local DRV government , and declared French authority restored in Cochinchina . Guerrilla warfare began around Saigon immediately , but the French gradually retook control of the South and North of Indochina . Hồ Chí Minh agreed to negotiate the future status of Vietnam , but the talks , held in France , failed to produce a solution . After over one year of latent conflict , all-out war broke out in December 1946 between French and Việt Minh forces as Hồ Chí Minh and his government went underground . The French tried to stabilize Indochina by reorganizing it as a Federation of Associated States . In 1949 , they put former Emperor Bảo Đại back in power , as the ruler of a newly established State of Vietnam
Potsdam Conference
Potsdam Conference
First Indochina War