This is coolbert: Dien Bien Phu, Part IV.

Having made ready, both sides were prepared for the battle and both awaited the siege of Dien Bien Phu (DBP) to begin. General Giap commenced the fight, and used his superior combat power in a superior fashion. Massing all his 144 pieces of tube artillery and other fire support assets against one French strong point at a time, along with massed divisional size infantry assault, Giap was able to destroy three French strong points in the first three days of the siege!! One third of the French forces were destroyed in the first three days!! This massive firepower was not anticipated by the French, who could not respond in kind. The 24 artillery pieces of the French were sited in such a manner that they could not provide counter-battery fire against the Viet Minh [I personally doubt this would have had any impact on the results of the siege, given the disparity of the artillery assets of both sides]. French preparations for such an artillery assault were poor, this contributing greatly to their losses, no overhead cover or deep dugouts having been dug prior to the siege beginning. After losing three strong points in three days, the French now realized their terrible peril and hopelessness of their position. Overland resupply and reinforcement were impossible. The airstrip was so cratered from shelling as to make it impossible for aircraft to land and take off. And if engineer support repaired the runways, aircraft landing were terribly susceptible to attack from the Viet Minh artillery. Aerial resupply was difficult to very near impossible. The concentrated fire of the 36 AAA guns of the Viet Minh made approaching aircraft fly higher, not allowing for pin-point bombing from ground attack aircraft or for accurate air dropping of supplies. The French did reorganize their defenses and did reinforce with one parachute battalion parachuting into the garrison after the siege had begun. But the severe damage had already been done. The French defenders did proceed to inflict upon the Viet Minh very severe losses [at the end of the siege, 8000 Viet Minh and 2000 French troops were buried at DBP]. But this only prompted the determined Viet Minh to adopt traditional siege tactics, sapping, mining, trenching. In the end, whatever measures the French took were fruitless. The surrender of the French forces at DBP was the decisive battle of the first Indo-China war. But not as the French had foreseen!

coolbert.