I apologize for the time it has taken for me to get back to you on this, but this was a question that required plenty of thinking.

Now, you're making a logical assumption in believing that the French military establishment had experience worth in gold just waiting to be dissected and applied as a countermeasure against insurgents. Being in the mindset of an insurgent as a counterinsurgency force is vital and having that fresh of an experience to use seems like a logical thing to take advantage of.

However, this sort of thinking disregards the complexity of the conflicts that were facing France between 1946 and 1962.

First, I think it's wise to look at the men in charge. What about the generals? Did they have any actual experience in the French resistance? Early generals like Jacques-Phillip de Leclerc and Jean Étienne Valluy, or generals like Jean de Lattre de Tassigny and Raoul Salan (who'd serve as a general both in Indochina and Algeria) were not involved in the French underground resistance. They all served in WWII alongside Free French Forces under Charles de Gaulle, but never in an underground capacity. There were few exceptions however, with generals like Henri Navarre and Maurice Challe who served in the Organisation de résistance de l'armée (ORA). However, there are no indications that they applied knowledge or experience from their resistance days onto their strategies.

In the case of Indochina, we have to consider the fact that a majority of the war was treated as a conventional, colonial war by the French Far East Expeditionary Force. There was relatively little counterinsurgency strategies put into action during this conflict in as much as it was fought with conventional, mechanized means. Perhaps the only real callbacks to WWII were the formation of French parachute regiments, which was a direct inspiration from the introduction and use of paratroopers by Allied and German forces, and the introduction of Groupe Mobiles by De Lattre, based on the US combat commands. Both of these reflected the conventional reality of WWII, not the unconventional experiences of the French Resistance and in my view gives us an insight into the sort of war that the French were waging in Indochina. The nature of the war in Indochina would develop and change from a conventional versus unconventional situation to a point like Dien Bien Phu where the Vietnamese Viet Minh defeats the French at their own game: a conventional battle.

During the Algerian War, the strategists drew mostly from the French Indochina War. In particular, Col. Charles Lacheroy's Guerre Révolutionnaire became the focal point of strategic thinking about what the "other side" was doing. Lacheroy and other contemporary theorists took a lot of lessons from the defeat in Indochina and realized that to fight against revolutionary warfare, you had to fight fire with fire; it was a fight about the population and you had to counter the revolutionaries with their own tricks. Today, we'd call this a form of population-centric counterinsurgency.

The biggest problem with Lacheroy's theory lies in the understanding of the reasons for insurgencies to exist to begin with. Based on a complete misreading of the French Indochina War, the theory arrives at a conclusion that insurgency movements all around the world are part of a worldwide conspiracy meant to spread communism all around the world. This meant that in the minds of French professional soldiers, the war that the FLN fought was not a war of national liberation but a revolutionary war meant to expand communism from Moscow to Algiers. This is of course a preposterous idea in hindsight but at the time, with the devastating defeat in Indochina for the French professional troops, they saw their role as being the bulwark against communism spreading into Europe and beyond.

It is at this point where we can truly see how far the French military thinking surrounding counterinsurgency had come since 1946 and shows how fast the realities of Cold War thinking had latched on to the French professional military, accelerated by a catastrophic defeat. What use would the experiences of the French resistance have during a time when both guerilla warfare and counterinsurgency was becoming modern?

Although the French resistance had no real place in the military planning, it did come to have a prominent place in the thinking of those carrying out counterinsurgency and those fighting against it. French supports of the FLN drew comparisons between the French resistance and the fight that the FLN was carrying out. The outcry in 1958 after the reveal of widespread use of torture by French forces in Algeria was a painful reminder of how the Nazis had used it against Frenchmen. Referring to the Oradour-sur-Glane massacre in 1944 by the 2nd SS-Panzer-Division "Das Reich, one French Foreign Legion corporal in Algeria in a poignant realization went as far as to write that "If one day there was a new Nuremberg trial, we will all be guilty: Oradours, we are carrying them out every day."