I'm listening to Dan Carlin's Hardcore History podcast about World War 1, and have just gotten to the point where the Grand Retreat halted and reversed the German advance at the Battle of the Marne.
Why did the German generals swerve from taking Paris? Did Moltke issue orders to pursue the French forces instead of taking the city, or did Kluck and Bülow decide of their own initiative?
I thought that whole idea of the German invasion of France was to force a quick and favorable armistice with enough time to get back defenders to the Russian border, it seems like taking Paris and then suing for terms would be the most effective approach, rather than trying to envelop and destroy the entirety of the enemy.
The major thing is that taking Paris was not going to be some cake walk. Liege was hopelessly outnumbered and double pincered and it still took the Germans something of over a week to neutralize them fully. Paris was Liege on steroids. Shit Paris was Verdun on steroids. Fortresses that unlike Liege were supported by a functionally sized armies and artillery.
The siege of Paris would have looked more like Verdun c. 1916 than anything else. This is doubly so because the German forces were not only at nearly half strength but also were outnumbered by French artillery with a factor 2:1. Triple so considering that the French 6th army was newly formed in there and at full strength.
The simple fact is that the plan was a sucker punch, a gamble. It was a gamble that they also thought they were winning; they bad thoroughly bought into their own little fantasy of a Cannae repeat. They thought the French army was in total and utter route so rather than slow the offensive down the plan was to speed up. To crush them. The simple reality is that they were not thinking very rationally. But it was a nigh unwinnable situation regardless if the seiged or not.
If you would like a great work on this check out Holger Herwigs The Marne: The Opening of the First World War, it handles the lead up to this battle and the details of why the Germans failed in depth.