In late 1952, in a bid to block the advance of the Democratic Republic of Vietnam’s (DRV) army into northwestern Vietnam and Laos, General Raoul Salan transformed Na San, a small upland village located along the Lao border, into a major entrenched position. Some 20,000 men were transferred to Na San to turn it into a “usine de guerre fabuleuse pour l’époque”. At the height of the work, Dakota planes were landing or taking off every 15 minutes. The French dug trenches, installed heavy artillery, and built an airbase to supply the camp from afar. A defensive fortress, supplied by air, was thus waiting for the Vietnamese when they attacked.
General Vo Nguyen Giap was confident that he could take the isolated camp and consolidate his hold over strategically important Tai regions in northwestern Vietnam and northern Laos. He had taken Nghia Lo from the French earlier that year; he counted on doing the same at Na San. However, his intelligence services failed to provide him with accurate information on the new type of defensive war Salan was preparing for him in Na San. On 30 November, Vo Nguyen Giap sent waves of his troops from the 308th and 312th divisions against the camp. He was shocked by the ferocity of the French reponse. Enemy artillery and aerial bombing decimated his men attacking under the cover of night. Indeed, French artillery fired 5,600 mortars alone during the night of 30 November–1 December. No sooner had the battle started than Giap had to call it off on 2 December 1952. The Vietnamese lacked the artillery they needed to knock out such a fortified position. Nor did they have the logistical capacities to transport large quantities of such artillery to the battlefield. Vo Nguyen Giap also realized that his inability to take out the airstrip meant that the French could continue to supply the camp. Instead of taking Na San, the Vietnamese simply decided to go around it and a few months later Salan pulled his troops out of Na San.
While Na San was a crushing defeat, the DRV also learned precious lessons. Vo Nguyen Giap sent intelligence teams back to the battlefield to study the fortified camp carefully. Indeed, the lessons of Na San served the DRV well when the French decided, in the following year, to set up “a super Na San” not too far away, in a valley named Dien Bien Phu. What General Henri Navarre (and others) did not anticipate was that the Vietnamese would deliver their artillery to Dien Bien Phu and knock out the French airstrip early on. For both the French and the Vietnamese, Na San and Dien Bien Phu were thus closely intertwined. As one French analyst has correctly described French strategy: “Dien Bien Phu est inscrit dans Na San”. No Vietnamese military historian worth his mettle would disagree. For Na San was an integral part of DRV preparations for Dien Bien Phu.