Japanese invasion of French Indochina

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.

Source: Wikipedia — Japanese invasion of French Indochina (CC BY-SA 4.0)