In 1937, flush with victory over the vicious Röhm regime in Germany, the Popular Front government of Leon Blum begins to institute a series of reforms of French colonial policy. In Indochina, legal reforms are initiated to end discrimination against native Indochinese. The middle-class nationalists of the Viet Nam Quoc Dan Nang, or Vietnamese National Party, reject Blum's reforms, demanding an immediate end to French rule. The peasant-based Indochinese Communist Party, encouraged by the Communist International in Moscow, choose to cooperate with the new policy.
The death sentence that had been passed in absentia against Communist leader Nguyen Sinh Cung (aka Nguyen Ai Quoc, "Nguyen the Patriot") is overturned, and he returns to Indochina from Moscow. Pham Van Dong and Le Duc Tho are released from prison, as are the wife and child of Vo Nguyen Giap. Land reforms are initiated in Nguyen Ai Quoc's native Nghe An Province.
In June 1940 the Communists withdraw from the Popular Front in France, and the Blum government falls, to be replaced by a right-wing coalition under Henri de Kerillis. Blum's reforms in Indochina are abolished, and the Indochinese Communist Party is outlawed. A revolt in Nghe An Province is brutally repressed, and the Communist leadership goes into hiding or flees Indochina.
Nguyen Ai Quoc, now going under the name Ho Chi Minh, "He Who Enlightens", retreats to a cave in the mountains of Cao Bang Province. There, he and Vo Nguyen Giap expand their organization to include remnants of the Vietnamese National Party, creating an organization called the League for the Independence of Vietnam, the Viet Nam Doc Lap Dong Minh, or Viet Minh.
For the next six years, the Viet Minh expands throughout Indochina, particularly in the area around Hanoi. The expulsion of the Japanese from China in 1945 by the Red Army brings a steady stream of money and munitions from the USSR to the Viet Minh, and Ho is able to build up a large guerilla army throughout Tonkin and northern Annam.
A return to power by Blum in July 1946 prompts a right-wing coup attempt in France, and fighting breaks out in Indochina between pro-Blum Loyalist troops and pro-coup Nationalists. This is the signal for the Viet Minh's uprising. The Viet Minh seize control of several cities in Tonkin, including Hanoi, and also the Imperial capital of Hue, forcing the Emperor Bao Dai to flee to Saigon. Ho declares himself head of a new Democratic Republic of Vietnam.
By the beginning of August Indochina is a patchwork, with some areas controlled by the Loyalists, some by the Nationalists, and some by the Viet Minh. With the failure of the coup in France the Loyalists and Viet Minh both advance against the Nationalists. The Loyalists are reinfoced by fresh troops from France. Ho politely declines Marshal Gordov's offer of Red Army
reinforcements, mindful of the fate of Chiang Kai-shek. Instead, he uses the continued flow of Soviet weapons to strengthen his position in Indochina.
Wishing to avoid further fighting in Indochina, Blum sends Foreign Minister Robert Schuman to Hanoi to negotiate with Ho. Ho demands French withdrawal from Indochina and recognition of Vietnam's independence. Schuman offers Indochina dominion status within the French Union, with Vietnam, Laos and Cambodia becoming autonomous devos. Ho is inclined to reject Schuman's offer and press for full independence, but an influential advisor named Ngo Dinh Diem urges him to accept, pointing out that Vietnam can declare independence after the Vietnamese militia have supplanted French troops.
Diem and Ho are both elected to the Vietnamese Chamber of Deputies in elections held in September 1946, and Diem surprises everyone by gaining the support of a majority of the Deputies, becoming the first Premier of the Vietnamese Devo. General Jean de Lattre de Tassigny, first Governor-General of the Dominion of Indochina, vetoes Diem's choice of his brother Ngo Dinh Nhu for the post of Interior Minister, and pressures Diem into appointing Vo Nguyen Giap.
In October 1947 Diem introduces a measure into the Chamber of Deputies calling for the Vietnamese Devo to secede from Indochina and form an independent state. Ho is suspicious of Diem's motives, and the Viet Minh Deputies oppose the measure, which is defeated. Diem asks de Lattre to dissolve the Devo's Chamber and call for new elections. The result is an electoral victory for a Unionist coalition led by the Viet Minh, and Ho succeeds to the Premiership in November.