Hi all. I'm sorry if this is a silly question but I am currently reading Alastair Horne's The Fall of Paris, and am slightly confused as to the purpose of Trochu's siege preparations. I feel like I'm missing something obvious, but hadn't the war been lost decisively by France by Sedan at the latest? Was this not as clear to the French government in 1870 as it is today? Given the military situation following the first six weeks of the war, preparing for a siege seems like an exercise in futility, only serving to prolong the war and cause unnecessary suffering for the population of the city.
Well, the difference between the French government that surrendered at Sedan and Paris is a matter of who is governing. Long since the first French Revolution, Paris had been a governing body of it's own. So with the surrender of Napoleon III and the dissolution of the Second Empire, the Parisian government had declared itself a Commune independent of the French government that was establishing itself in the wake of the fall of Napoleon.
This Commune was a step towards absolute Communism with many policies (which I sadly can't go into much detail) inspired directly by Karl Marx. This Commune would thus be sieged by the Republic. It would last a year but was a failure of Communism due to the siege conditions at the least.