Battle of Dien Bien Phu

The Battle of Dien Bien Phu (French: Bataille de Diên Biên Phu; Vietnamese: Chiến dịch Điện Biên Phủ) was the climactic confrontation of the First Indochina War between the French Union's French Far East Expeditionary Corps and Viet Minh communist-nationalist revolutionaries. The battle occurred between March and May 1954 and culminated in a comprehensive French defeat that influenced negotiations over the future of Indochina at Geneva. Military historian Martin Windrow wrote that Dien Bien Phu was "the first time that a non-European colonial independence movement had evolved through all the stages from guerrilla bands to a conventionally organized and equipped army able to defeat a modern Western occupier in pitched battle."

As a result of blunders in French decision-making, the French began an operation to support the soldiers at Dien Bien Phu, deep in the hills of northwestern Vietnam. Its purpose was to cut off Viet Minh supply lines into the neighboring Kingdom of Laos, a French ally, and tactically draw the Viet Minh into a major confrontation that would cripple them. The Viet Minh, however, under General Vo Nguyen Giap, surrounded and besieged the French, who were unaware of the Viet Minh's possession of heavy artillery (including anti-aircraft guns) and their ability to move these weapons through difficult terrain, up the reverse slopes of the mountains surrounding the French positions, dig tunnels through the mountain, and position the artillery pieces overlooking the French encampment. This positioning of the artillery made it impervious to counter battery fire. When the Viet Minh opened fire, the one-armed French artillery commander accepted responsibility for his failure and committed suicide with a hand grenade. The Viet Minh occupied the highlands around Dien Bien Phu and bombarded French positions. Tenacious fighting on the ground ensued, reminiscent of the trench warfare of World War I. The French repeatedly repulsed Viet Minh assaults on their positions. Supplies and reinforcements were delivered by air, though as the French positions were overrun, the French perimeter contracted, and the anti-aircraft fire took its toll, fewer and fewer of those supplies reached them. The garrison was overrun after a two-month siege and most French forces surrendered. A few escaped to Laos. The French government resigned and the new Prime Minister, the left of centre Pierre Mendès France, supported French withdrawal from Indochina.

The war ended shortly after the Battle of Dien Bien Phu and the signing of the 1954 Geneva Accords. 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, and the south becoming the State of Vietnam under Emperor Bao Dai, preventing Ho Chi Minh from gaining control of the entire country. The failure of North and South to enter into negotiations about holding nationwide elections in 1956, as had been stipulated by the Geneva Conference, would eventually lead to War in Vietnam (1959–1963) and escalation to the full participation of American combat troops following the Gulf of Tonkin incident in 1964.