Japanese invasion of French Indochina

Japanese invasion of French Indochina
Part of French Indochina in World War II, the South-East Asian theatre of World War II and the Pacific Theater of World War II
Imperial Japanese Army soldiers advance to Lang Son, in September 1940 in French Indochina.
Date 22–26 September 1940 (4 days) Location French Indochina Result Japanese victory Territorial changes Japanese occupation of French Indochina from Lang Son.
Belligerents
Japan	Vichy France  French Indochina	Vietnam National Restoration League Vietnam National Building Force
Commanders and leaders
Aketo Nakamura Takuma Nishimura	Jean Decoux Georges Catroux Maurice Martin	Trần Trung Lập
Casualties and losses
Unknown	Uncertain (~900 according to sources)	2 battailions[1]

The Japanese invasion of French Indochina (仏印進駐, Futsu-in shinchū), (French: Invasion japonaise de l'Indochine) was a short undeclared military confrontation between Japan and Vichy France in northern French Indochina. Fighting lasted from 22 to 26 September 1940; the same time as the Battle of South Guangxi in the Sino-Japanese War, which was the main objective as to why Japan occupied Vietnam during this time.

The main objective of the Japanese was to prevent China from importing arms and fuel through French Indochina along the Kunming–Haiphong railway, from the Indochinese port of Haiphong, through the capital of Hanoi to the Chinese city of Kunming in Yunnan.^[2]

Although an agreement had been reached between the French and Japanese governments prior to the outbreak of fighting,^[3] authorities were unable to control events on the ground for several days before the troops stood down. As per the prior agreement, Japan was allowed to occupy Tonkin in northern Indochina, and thus effectively blockade China.