First Indochina War
The First Indochina War has the unwanted distinction of being one of the first proxy wars of the Cold War. During WWII the Japanese had invaded and taken control of Vietnam, which at the time was part of French Indochina, breaking their stranglehold on the country for the first time in just under a century.
The French had added Vietnam to their colonial territories in South East Asia between 1858 and 1887, but from the beginning of this seizure of territory by the French, a Vietnamese resistance would birth and grow until the arrival of their Japanese liberators.
By the time the Japanese surrender just a few months later on August 22nd, 1945, it seemed that Vietnam would end up back in the hands of the western powers. However, as the Japanese troops were the only ones able to maintain order in the country they remained for a short time after the surrender.
The Japanese authorities were well aware that it would only be a matter of time before the French came back to retake control of Vietnam, so with that in mind, they allowed nationalist groups, most notably the Viet Minh, an anti-imperialist national independence coalition founded by Hồ Chà Minh, to seize control of public buildings and a stockpile of weaponry.