When Japanese troops arrived in Tonkin (the northernmost tip of French Indochina) in 1940, they paused and considered their position. Did they want to commit troops to a conflict they didn’t need or could they achieve what they wanted by other means? What followed over the next 5 years was a ‘dance’ between an overwhelming Asian military power and a weakened European colonial administration who would be allowed to stay in place as long as they did what they were told.

  

Nationalist fighters from the late 1940's

 

 With a pro-Nazi regime in Paris (the ‘Vichy’) the ambiguity of the situation was exploited by the Japanese who could station troops in Indochina, plunder what they wanted from their new territory, but not have to fight. The French administration, under Governor Jean Decoux, sympathetic to the Vichy nationalist brand, continued to rule but had to show their loyalty by such tests as finding and handing over Allied airmen who may have been shot down over Indochina. 

This situation lasted until Allied forces, led by American and British troops, liberated France from Nazi Germany in late 1944, and the Vichy regime quickly disappeared.

French defeat

Following this defeat, in March 1945, the Japanese turned on the French administration, arresting most of them and killing many. They also invited the local Cambodians to rule themselves ‒ an offer that was taken up enthusiastically by the early leaders of the Cambodian nationalist movement, such as Son Ngoc Thanh.

The self-rule lasted barely six months, as the defeat of Nazi Germany was followed by the defeat of Japan, and the new French Government, supported by the British and even the departing Japanese, took back what they believed to be theirs.

 However, the new France, led by General de Gaulle, was a battered and bruised country, where many of its population had died during the course of the German occupation in the war, resisting the invaders. France was now divided on the ambition to impose occupation by force on others. Faced with a young nation energised by the dream of independence, things in Indochina were never going back to how they were before 1940.

 In Cambodia, Norodom Sihanouk, a young prince, had been selected by the French as the new monarch. As became the mark ‒ and challenge ‒ of his public life, Prince Sihanouk was a nationalist who had been chosen to be the head of the country by the authority that resisted that dream.

 While the Vietnamese had the Vietminh, Cambodia had its own nationalist guerrillas ‒ the Issaraks. They quickly made many parts of the country, especially around the forested, hilly outcrops and mountains of Kampot province, ungovernable by the French administration.

The reality of their unwinnable situation resulted in France granting the Kingdom of Cambodia independence in 1953. This came one year before the French departed completely from Indochina after their defeat in the mountainous valleys around Dien Bien Phu in Tonkin (North Vietnam). 

French and colonial prisoners soldiers being marched away to an unknown fate after their defeat at

Dien Bien Phu1

For further information on this period see "Early struggles in the Southwest Zone"

1. https://commons.wikimedia.org/wiki/File%3ADien_Bien_Phu_1954_French_prisoners.jpg