Indochina; Wikimedia Commons

The fall of France to German forces in June 1940, and subsequent establishment of the Vichy government, weakened French colonial rule of Indochina (modern day Cambodia, Laos, and Vietnam). Soon France permitted the establishment of Japanese military bases in Indochina.

In October 1940, Thailand attacked across the border of Indochina, launching the  Franco-Thai War. Although the French won important victories, Japan demanded that parts of Cambodia and Laos, long held by France, be returned to Thai control. Vichy France continued to administer Indochina until March 1945, when the Japanese took direct control and established their own puppet state, the Empire of Vietnam.