After the November 20 parachute drop, Dien Bien Phu quickly became a fortified area, capable of receiving 12,000 combatants. But why did you choose such a place? Because the French command is losing patience. Engaged in a war with the revolutionary army of the Vietminh since December 19, 1946, he absolutely needs a spectacular victory. He therefore chose to occupy Dien Bien Phu, more than 300 km inside the territory held by the enemy.
In Saigon, the command is not well established on the role that Dien Bien Phu will be called upon to play. Will it be a collection center for the Lai Chau garrison? Or a hedgehog in an essential strategic position? Or a starting point for an offensive, as General Cogny declares? Perhaps this is a trap set for General Giap's troops? It could also be a fixation abscess before an offensive on the Red River Delta...
Before being replaced by General Navarre, General Salan, Commander-in-Chief of the French Expeditionary Corps in Indochina, had declared that Laos could only be defended by holding Dien Bien Phu, Na San or Lai Chau. Navarre severely criticized him for having chosen to fortify Dien Bien Phu, located at the bottom of a valley.
Navarre, however, saw in this basin 16 kilometers wide by 9 kilometers wide an ideal base from where he could mount operations. He considered the enemy incapable of investing the fortifications of Dien Bien Phu and bombarding its airstrip with artillery from the neighboring hills, 16 kilometers away.
For a while, Dien Bien Phu becomes almost a tourist place visited by many French and foreign, political or military personalities. From all sides, the entrenched camp attracts nothing but praise. One man, General Blanc, however, has reservations about its effectiveness in the monsoon period. His advice was ignored.
Among the visitors were General Spears, British military attaché, High Commissioner Malcolm McDonald, several American generals, including John O'Daniel , commanding United States Ground Forces in the Pacific. None of these highly competent characters questioned Dien Bien Phu's ability to resist an attack.
French military leaders were stricken with almost total blindness; and yet we are aware of the movements and possibilities of the opposing forces.
Navarre has therefore put the system in place, and Giap will take advantage of it. The Vietminh war council carefully analyzes the situation created in Dien Bien Phu by the French parachute drops of November 20. He ordered the 316th Division to attack Lai Chau to force its garrison to withdraw to the entrenched camp. But the same month of December 1953, the French command anticipates the plans of the Vietminh. The Lai Chau troops were evacuated by air in 183 rotations, four days before the arrival of the Viets. At Dien Bien Phu, the offensive actions and reconnaissance missions ordered by General Cogny began to cost dearly. Two operations, baptized "Ardèche" and "Regate", were undertaken by a group of paratroopers under the orders of Lieutenant-Colonel Langlais.
The paratroopers left the base to liaise with the infantry light Laotian and Moroccan Tabors from Laos. The meeting point is fixed around Sop Nao, in a mountainous region, covered with a thick jungle, perfectly conducive to ambushes. The group is harassed by a very mobile enemy; the losses are so heavy that these long-range raids are soon abandoned; efforts will now focus on the hills surrounding the Dien Bien Phu site itself. divisions are moving towards Dien Bien Phu. Giap quickly mobilized his forces and the French garrison prepared to sustain a siege. Engineering specialists estimate at 36,000 tons the quantity of material supplies that will be necessary for the organization of the terrain. This would require 12,000 rotations of Dakota from Hanoi. It is unachievable. The genius only obtained 4,000 tons, 75% of which were barbed wire!
In fact, the battle between the French and the Vietminh was first and foremost a logistical battle. And the French command will lose it. The Vietminh carefully mapped out all the work to fortify the position, as he could clearly see them from the surrounding heights. The smallest trench stands out clearly against the bare ground. As for the occupants of the base, they see nothing of the enemy movements, so dense is the jungle. They are unaware that 55,000 local regulars and auxiliaries surround them. Giap's forces opened through the vegetation five roads towards Dien Bien Phu. They are traversed, at night, by 600 2.5-tonne Russian trucks, driving with all lights off.
No doubt, the French air attacks on the Lung Lo and Phadin passes been successful. But the traffic was never interrupted for very long.
Thousands of coolies work day and night to keep the supply routes in good condition. In addition, on the tracks, pack animals, mules and convoys of bicycles, each loaded with a hundred kilos, converge on the battlefield. Nothing can stop this procession of human ants. For its part, the entrenched camp can only rely on air transport, and everything must come from Hanoi.
Ten M24 Chaffee tanks are dismantled, each of them requiring five C47s and two Bristols to be removed. 105 and 155 mm guns, rations for 11,000 men, generators, water purifiers... But the air force, even with the help of the C119s provided by the Americans, will not be able to meet the demands.
The power of Giap's artillery, deployed around Dien Bien Phu, is impressive. The day before the attack, the besiegers had 144 field guns (75 and 105 American), 48 120mm heavy mortars, 30 75mm recoilless guns and 36 pieces of 37mm anti-aircraft artillery. During the battle, 12 Katyusha six-tube rocket launchers will go into action. The physical effort must have been enormous to pull these machines to their positions, on wet and slippery slopes.
On D-Day, Giap had a good stock of projectiles greater than the besieged could imagine. From March 13 to May 8, 1954, its guns will fire approximately 150,000 shells, including 30,000 rounds of approximately 105.
For its part, the French artillery will need an airlift of an incredible scale to resupply its parts. A total of 95,000 105 shells and 8,500 155 shells were dropped on the base. But a certain number fell beyond its perimeter, which was becoming increasingly restricted.
In the entrenched camp, the French had six batteries (24 guns) of 105 mm, a battery of 155 mm howitzers and 32 heavy 120 mm mortars.
Colonel Piroth, commanding the artillery, considers that these means are sufficient to stop any enemy infantry attack and to make effective counterbattery. He affirms:“No Vietminh cannon will fire more than three rounds without being destroyed. The power of the opposing artillery, its richness in ammunition, the skill of its gunners and the effectiveness of its camouflage are thus completely underestimated.
Contrary to all expectations, the guns of the Vietminh are served by excellent gun platoons, educated in camps in southern China. Their fire is directed and controlled by observers with a full view of the airfield and unprotected French batteries. From the first day of the attack, their power and precision will traumatize the besieged, whose counter-battery actions will be disorderly and without effect.
It is because the Vietminh 105s are impossible to locate and virtually invulnerable. They are well buried in their sockets, although this restricts their range of fire and makes them more difficult to handle. On the other hand, the enemy installed dummy cannons regularly misleading the observers.