La guerre Allemande
The first years following the Brunei War were almost exclusively spent to heal the wounds of the British blockade. The new French government aimed at strengthening the cultural and industrial foundations of the nation by implementing a series of political reforms and putting forward incentives for industrial growth.
The military development was set aside, either deliberately or subconsciously, since it was the military and its jingoistic ambitions that the people of France blamed for the tragedy of 1838-1840. However, this attitude nearly cost France another tragedy.
North Germans, having finally managed to force their neighbours (especially France) to accept a unified North German Federation, saw the troubles of France and the dire consequences of the Brunei war as an opportunity to achieve their ultimate goal, the unification of all the german states. However it was clear both to them and everyone else, that the road to the creation of a Pan-German state had to go through Alsace-Lorraine, a territory with mixed population currently under French rule. To achieve this, they focused on training a most formidable, modern and professional army and expected to take the ill equipped, ill trained and in disarray French military by surprise.
By the end of 1847, NGF had nearly achieved its goal, as its military prowess could not be matched by the French. However, at that point a combination of luck, a series of strategic errors from the Germans and the rise of General Benzaine as the head of War Cabinet in France turned the tide of events.
Colombia, in fear of the rise of an aggressive Brazil, decided to act and launched a pre-emptive strike hoping to contain their neighbour in the south. NGF, a close ally to Brazil, chose to provide military assistance and commited a significant amount of troops and ships to this campaign, thereby delaying the invasion to Alsace-Lorraine.
This delay gave the necessary valuable time to General Benzaine to literally reform the entire French army within 2 years. Priority was given to bringing the French military up-to-date with the latest technological developments and acquiring the state-of-the-art war equipment. The gap between the German and the French professional armies closed considerably within these two years, since the Germans had already exhausted the men who were willing to be conscripted into the army.
When the war finally came, the odds were now in favour of France. The difference in the sophistication and quantity of armament had been eradicated, while the French had the advantage of a superior mobilisation pool in sheer numbers, people who were willing to fight and die for their homeland.
The initial german assaults against the fortified positions in the border were repelled by the French. However, the decisive blow came when General Exelmans found a crack in the supply line of the German army and managed to take the german forts in Saarbrucken almost without a fight. This brilliant maneuver, practically cut the German forces in half and gave France a foothold to invade Rheinland. After that the war was short and NGF had no choice but to ask for peace terms.
The peace negotiations were long and intense and even Russia served as a mediator. However France was adamant in its claim. They argued that since Alsace-Lorraine was the german objective of this war, France had to demand something similar. However, the true motive between this demand was the fact that France knew very well that NGF's desire for Alsace-Lorraine would not die with this war. They knew it would be a matter of time before NGF reorganised and was ready for war. So as far as France was concerned there was only one option, to weaken NGF as more as possible.
NGF had no option but to cede Rheinland. France succeeded in weakening NGF, but also made sure that revanchism would be the dominant force behind NGF geopolitical actions in the near and foreseeable future.