The First Indochina War starts.

The First Indochina War began in French Indochina on 19 December 1946, and lasted until 20 July 1954. Fighting between French forces and their Vi?t Minh opponents in the south dated from September 1945. The conflict pitted a range of forces, including the French Union’s French Far East Expeditionary Corps, led by France and supported by B?o ??i’s Vietnamese National Army against the Vi?t Minh, led by Ho Chi Minh and the People’s Army of Vietnam led by Võ Nguyên Giáp. Most of the fighting took place in Tonkin in northern Vietnam, although the conflict engulfed the entire country and also extended into the neighboring French Indochina protectorates of Laos and Cambodia.

At the Potsdam Conference in July 1945, the Combined Chiefs of Staff decided that Indochina south of latitude 16° north was to be included in the Southeast Asia Command under British Admiral Mountbatten. Japanese forces located south of that line surrendered to him and those to the north surrendered to Generalissimo Chiang Kai-shek. In September 1945, Chinese forces entered Tonkin, and a small British task force landed at Saigon. The Chinese accepted the Vietnamese government under Ho Chi Minh, then in power in Hanoi. The British refused to do likewise in Saigon, and deferred to the French there from the outset, against the ostensible support of the Vi?t Minh authorities by American OSS representatives. On V-J Day, September 2, Ho Chi Minh had proclaimed in Hanoi the establishment of the Democratic Republic of Vietnam. The DRV ruled as the only civil government in all of Vietnam for a period of about 20 days, after the abdication of Emperor B?o ??i, who had governed under Japanese rule. On 23 September 1945, with the knowledge of the British commander in Saigon, French forces overthrew the local DRV government, and declared French authority restored in Cochinchina. Guerrilla warfare began around Saigon immediately, but the French gradually retook control of the South and North of Indochina. Hô Chi Minh agreed to negotiate the future status of Vietnam, but the talks, held in France, failed to produce a solution. After over one year of latent conflict, all-out war broke out in December 1946 between French and Vi?t Minh forces as Hô and his government went underground. The French tried to stabilize Indochina by reorganizing it as a Federation of Associated States. In 1949, they put former Emperor B?o ??i back in power, as the ruler of a newly established State of Vietnam.

The first few years of the war involved a low-level rural insurgency against the French. In 1949 the conflict turned into a conventional war between two armies equipped with modern weapons supplied by the United States, China and the Soviet Union. French Union forces included colonial troops from the whole former empire Moroccan, Algerian, Tunisian, Laotian, Cambodian, and Vietnamese ethnic minorities, French professional troops and units of the French Foreign Legion. The use of metropolitan recruits was forbidden by the government to prevent the war from becoming even more unpopular at home. It was called the “dirty war” by leftists in France.

The strategy of pushing the Vi?t Minh into attacking well-defended bases in remote parts of the country at the end of their logistical trails was validated at the Battle of Nà S?n. However, this base was relatively weak because of a lack of concrete and steel. French efforts were made more difficult due to the limited usefulness of armored tanks in a jungle environment, lack of strong air forces for air cover and carpet bombing, and use of foreign recruits from other French colonies. Võ Nguyên Giáp, however, used efficient and novel tactics of direct fire artillery, convoy ambushes and massed anti-aircraft guns to impede land and air supply deliveries together with a strategy based on recruiting a sizable regular army facilitated by wide popular support, a guerrilla warfare doctrine and instruction developed in China, and the use of simple and reliable war material provided by the Soviet Union. This combination proved fatal for the bases’ defenses, culminating in a decisive French defeat at the Battle of Dien Bien Phu.

At the International Geneva Conference on July 21, 1954, the new socialist French government and the Vi?t Minh made an agreement that was denounced by the State of Vietnam and by the United States, but which effectively gave the Vi?t Minh control of North Vietnam above the 17th parallel. The south continued under B?o ??i. A year later, B?o ??i would be deposed by his prime minister, Ngô ?ình Di?m, creating the Republic of Vietnam. Soon an insurgency, backed by the north, developed against Di?m’s government. The conflict gradually escalated into the Vietnam War/American War also known as the Second Indochina War.