I may be verbally assaulted for this, but here goes. It is my impression that France and the French people have a need to be relevant and a need to be recognized as a great power. The French do seem to believe in French exceptionalism. What would such a loss in WWI do to this fundamental belief system? Is the French psyche be damaged to such an extent that radical violent change is inevitable, and what is the finished product going to look like?
I intend no insult to the French, so please do not take my comments as such!
You are right to say that there is such a thing as French exceptionalism in a way. The same way there is such a thing as American, British and German exceptionalism. Whenever a great power fell to the ground, the adjustment was very painful and very hard to do for the nation in question. Spain and the Spanish psyche were damaged by the loss of the Spanish Empire for example. You can also make the argument that Britain still has not completely adjusted to the loss of its Empire in some ways.
As I have argued before on a lot of other threads, the potential for a French "nazism" is close to non existent. Nazism was very much a German ideology, with roots dating back from the German philosophers of the 19th century and the German yearning to prove itself as a newly united nation to the rest of the world. If an authoritarian regime arise in France, it will likely be very reactionary, mildly antisemitic, catholic and agrarian in its outlook (nearly 60% population was living in the countryside at that time). Salazar Portugal and Franco Spain during the thirties, forties and fifties are a good approximation of what this authoritarian regime would look like.
Assuming a quick German victory over France in 1914, France losses would likely amount to the following:
-Longwy-Briey Iron Ore field in Lorraine. Possibly including the town of Nancy, essentially the entire Meurthe et Moselle département.
-The Fortress of Belfort (not a given but a strong possibility due to its strategic location)
-French Equatorial Africa
Other possible losses include Madagascar and parts of West Africa like Dahomey. France losing the entirety of Lorraine is unlikely since the region has little economic value a forced demilitarisation would negate the strategic advantage of the Vosges Line. A loss of the Nord Pas de Calais seems unlikely unless Germany is able to achieve an overwhelming victory after several years of wars (time for the hawks to push for more annexations).
Indochina might be taken by the Germans as well, but I think that Germany pushing for more concessions and advantages in China is more likely.
Morocco is another possible loss as well.
The really important thing is whether or not Germany would try to push France into joining a custorm and economic union favouring German products and German exports. If this is the case, France will de facto become a German puppet state and its economy will become hugely dependent on the German one.
So you are saying that France may turn isolationist?
Would it be too much for France to turn into a German client state, with Berlin pulling the strings of power in Paris? Germany is going to be scary powerful after a decisive victory!
I would say that isolationism is very likely whether or not the post war regime is democratic or authoritarian. The loss of the Lorraine iron ore mines and ironworks will have a severe negative impact on the French economy. France only major industrial region following the war will be the very likely damaged and looted Nord Pas de Calais; alongside Paris and the Seine valley. This alone will drastically lower the industrial potential necessary for a revenge and instill a deeply defensive and inwards looking mentality. As far back the early 1900s, French politicians were increasingly aware that France strategic position was becoming weaker, in a large part because of Germany dynamic economy and booming population (a huge source of worry).
If post war France is cut from her British and Russian allies and does not become part of the German economic sphere. Then isolationism will be the only option available. If Russia Tsarist regime is still in place, moves waimed at rebuilding the Franco-Russian alliance will be made but said alliance might focus more on economy and trade rather than on "let's attack Germany from two sides". The Franco-British Entente will be here to stay, particularly is Britain is pushed out of the continent entirely and loses some colonies in Africa. It would be in the best interest of both parties for said Entente to gain an economic dimension, France would be Britain only export market on the contient and vice versa.
The only place in Europe where France will be able to regain some influence and some allies (this also applies to Britain) will be in Spain and Portugal. Italy will quickly side with Germany if the latter is victorious, who knows if they honour their alliance at the last minute they might even gain some crumbs (Nice, parts of Savoy).
The only asset a defeated France will still have at her disposal will be her large colonial Empire. If Indochina is lost and taken by Germany, then the remaining Empire in Africa and the confettis elswhere is essentially worthless. Studies made by French historians (Jacques Marseilles) have proven that Indochina was France only profitable colony. Indeed it was exporting rubber, coal, minerals and other rare goods in large quantities by 1914 and even more by 1939. North Africa was only exporting agricultural produce, the Sahel and West Africa were underdevelopped in all respects. Places like Guiana, Martinique and such are still poor and dependent on money transfers from mainland France. New Caledonia was profitable but that's about it.
What is likely to happen is that refugees from the Lorraine will be encouraged to resettle in Algeria and throughout the colonial Empire (it happened in 1871 with Alsatian refugees). Depending on how foresighted post war governments are, a strong "push" to develop the overseas colonies might very well happen. Predicting likely results is a tricky exercise, it could go either way simply put but West Africa can't become as profitable as India was to the British or as the Congo would become to the Germans.
In a nutshell, isolationism is pretty much the only way forward. The only way France would be able to improve and strengthen its position, would be by investing in her economy and in her colonies. Essentially trying to achieve what Japan achieved after its defeat in 1945. Nevertheless there are no obvious markets to exports, no obvious investors and no obvious raw materials easy to tap into (nuclear power on Sahelian Uranium is a long way away).