Terrain aside, Henri Navarre, commander of the French forces in Indochina, first decided to occupy Dien Bien Phu to block a Vietnamese attack on Laos. Dien Bien Phu was a strategic location that would allow the French to control routes from northwestern Vietnam to Laos (or so he thought).

Looking at the terrain, Navarre’s tactical thought process went something like this:

• The mountains surrounding the valley were steep and covered in jungle.
• This would make it difficult for any force to receive supplies, and impossible to receive heavy artillery, unless that force had access to air transport.
• Only the French had access to air transport!
• Without artillery and air support, the only way the Vietnamese could attack was with their infantry.
• Based on previous Vietnamese infantry attacks, they would probably charge en masse, to which French firepower was the perfect counter.

When given the command, Navarre had protested that he knew absolutely nothing about Asia, but he was not exactly wrong about the difficulties the terrain posed to the enemy. We now know that the Vietnamese were able to supply their force with food and heavy artillery, but this was not easy at all. It was only made possible by mobilising (and/or coercing) hundreds of thousands of Vietnamese into supporting the offensive as porters.

One method of getting rice to the besieging force, for example, involved loading it onto bicycle convoys. 5 to 6 men had to guide every single bicycle up and down steep slopes, and there were many, considering the mountainous terrain. Rivers had to be forded first by one brave soul and a rope, after which all the rice had to be moved across without it getting wet, followed by all the bicycles.

Artillery, also, had to be moved up the mountains, over the crest and into position using nothing but muscle power. Men died, crushed by the artillery they were moving over narrow mountain paths.

When the monsoon rains came, the Vietnamese fared even worse than the French, with trenches and dugouts filling with water and diseases spreading amongst the troops.

The logistical difficulties can be seen from the French being allowed to sit in their “fortress” for nearly 4 months before the attack came. While they were receiving regular supplies via air transport, General Vo Nguyen Giap, commander of the Vietnamese forces, was in a state of constant worry over whether he had enough rice for his men.

When the attack did come on March 13, although the French could not believe that they were coming under artillery fire, Vietnamese infantry tactics were indeed what they had been expecting. In the first three wave assaults, the death rate was nearly 30%, and many more were wounded badly enough that they would never walk again. Overflowing with wounded, Vietnamese medical facilities could not cope.

It was only in early April that Giap decided that a better strategy was to fight slowly and patiently instead of charging en masse and closing the gap.

Overall, in hindsight, it’s easy to see what went wrong with Dien Bien Phu. But putting oneself in Navarre’s shoes before the battle, one can also see that his assumptions were understandable. The more forgivable mistake, perhaps, is that the supply difficulties that he thought to be impossible to solve just turned out to be very, very, very difficult, but solvable. The less forgivable one is assuming that the Vietnamese were incapable of changing their tactics.

As for whether anyone thought that Dien Bien Phu was a bad idea, in his memoirs, Eisenhower wrote

Finally, they came along with this Dien Bien Phu plan. As a soldier, I was horror-stricken. I just said, ‘My goodness, you don’t pen troops in a fortress, and all history shows that they are just going to be cut to pieces… I don’t think anything of this scheme.’

Whether this is truly what he thought at the time is unclear - political considerations would have made it difficult for him to voice an honest opinion.

Navarre wrote in his memoirs that

No unfavourable opinion was expressed before the battle.

However, this is contradicted by French military records, which show that several staff officers objected to Operation Castor. On November 12, 8 days before the first French troops were due to parachute into the valley, the commander of French forces in Tonkin, Rene Cogny, wrote to Navarre

… found here little enthusiasm, among my staff as well as among the paras and aviators, for this operation.

During the final meeting between Navarre and his officers to work out the details, Colonel Dominique Bastiani, Cogny’s Chief of Staff, wrote in his notes that all were “unanimous in objecting”.

The wisdom of dropping paratroopers into a valley with an enemy garrison was questioned. General Jean Dechaux, head of the Northern Tactical Air Group, pointed out that the landing strip had to be well defended so that his planes could land and take off safely. Colonel Bastiani felt that Dien Bien Phu would become a distraction, tying up French troops and resources for little to no gain. Indeed, the Vietnamese were still able to strike at Laos - they simply went around Dien Bien Phu.

To the best of my knowledge, however, none of the French military objected on the grounds that the Vietnamese were going to surround them with heavy artillery. Instead, this was left to war reporter Brigitte Friang. After being airdropped into Dien Bien Phu, she told Charles Piroth, commander of the artillery,

My dear colonel, you must realise that the Viets are in the hills. They will fire straight at you.

In this, it was the civilian who proved to be prescient.

Morgan, T. (2010) Valley of Death: The Tragedy at Dien Bien Phu that Led America into the Vietnam War. Random House

Tucker-Jones, A. (2017) Dien Bien Phu: The First Indochina War 1946-1954. Pen and Sword Military

Bearden, R. C. (2015) Dien Bien Phu: Reducing Moral Hazard in Airlift Operations. Air University Press

Goscha, C. E. (2010) Hell in a Very Small Place: Cold War and Decolonisation in the Assault on the Vietnamese Body at Dien Bien Phu. European Journal of East Asian Studies, 2010, Vol. 9, No. 2, pp. 201-223. Brill