Battle of Dien Bien Phu

The Battle of Điện Biên Phủ was a climactic confrontation of the First Indochina War that took place between 13 March and 7 May 1954. It was fought between the forces of the French Union and Viet Minh.

The French began an operation to insert, and support, their soldiers at Điện Biên Phủ, deep in the autonomous Tai Federation in northwest Tonkin. The operation's purpose was to cut off enemy supply lines into the neighboring Kingdom of Laos (a French ally) and draw the Viet Minh into a major confrontation in order to cripple them. The French based their forces in an isolated but well-fortified camp that would be resupplied by air, a strategy adopted based on the belief that the Viet Minh had no anti-aircraft capability.

The communist Viet Minh, however, under General Võ Nguyên Giáp, surrounded and besieged the French. They brought in vast amounts of heavy artillery (including anti-aircraft guns) and managed to move these bulky weapons through difficult terrain up the rear slopes of the mountains. They dug tunnels and arranged the guns to target the French positions. The tunnels featured a front terrace, onto which the Viet Minh would pull their cannons from out of the tunnels, fire a few shots, to then pull them back into protective cover.

In March, the Viet Minh began a massive artillery bombardment of the French defenses. The strategic positioning of their artillery made it nearly impervious to French counter-battery fire. Tenacious fighting on the ground ensued, reminiscent of the trench warfare of World War I. At times, the French repulsed Viet Minh assaults on their positions while supplies and reinforcements were delivered by air. As key positions were overrun, the perimeter contracted, and the air resupply on which the French had placed their hopes became impossible as aircraft were shot down and runways were destroyed.

The garrison was overrun in May after a two-month siege, and most of the French forces surrendered. A few men escaped to Laos. Among the 11,721 French troops captured, 858 of the most seriously wounded were evacuated via the Red Cross mediation in May 1954. Only 3,290 were returned four months later, although it is believed that a small fraction of the outstanding missing troops were Vietnamese who had not yet been returned by the French, and did not necessarily die in captivity; adjusting for this, the death rate of French troops in captivity of the Viet Minh is estimated to be approximately 60%. The French government in Paris resigned. The new prime minister, the left-of-centre Pierre Mendès France, supported French withdrawal from Indochina.

The Battle of Điện Biên Phủ was decisive. The war ended shortly afterward and the 1954 Geneva Accords were signed. France agreed to withdraw its forces from all its colonies in French Indochina, while stipulating that Vietnam would be temporarily divided at the 17th parallel, with control of the north given to the Viet Minh as the Democratic Republic of Vietnam under Ho Chi Minh. With huge support by the US, the south became the State of Vietnam, nominally under Emperor Bảo Đại, preventing Ho Chi Minh from gaining control of the entire country.