BooNZ
Banned
This is a fascinating premise - one of the most interesting of recent times.
Schlieffen was more than just a plan, it was predicated on the Prussian (German) way of making war but the France of 1914 wasn't the France of 1870. Schlieffen provided a possible answer to that by using neutrality, speed and manoeuvre to gain a decisive advantage. Its existence and the premise on which it was created shaped German policy.
No, the Schlieffen Plan was the antithesis of the Prussian way of making war. It essentially surrendered German mobility and flexibility to seek a decisive battle at the furthest reaches of its logistical capacity.
If there is no plan or Schlieffen is so altered by Moltke as to be an essentially defensive object, the nature of the immediate pre-war period changes. The defences in Alsace and Lorraine, in particular, are built up even more strongly in the expectation of a French thrust in support of Russia. The immediate start of the war would be envisaged as offensive against Russia and defensive against France - the not inconsiderable advantages of terrain allied to the fortifications of the Kaiser Wilhelm Line (let's call it that) make it a different kind of campaign to what happened in OTL.
No, the Germans recognized there were no good options available for French offensives across the Franco-German border, so it per OTL, the Germans would likely only fortify key positions so as not to deter French offensives. The German counter attack doctrine explicitly contemplates enemy offensives...
So, on August 1st 1914 German forces strike against the Russians, supported by the Austrians in the south. Efficient mobilisation has brought substantial French forces (no British yet) to the border areas but they face substantial fortification and the Vosges Mountains which are heavily defended by the Germans. Initial French attacks lead to little ground gained and heavy losses. It isn't until substantial artillery pieces are brought in from Paris that the walls of the fortresses are breached and some ground captured (or liberated).
No, there were no substantial artillery pieces in Paris, unless you referring to re-tooling fortress guns, which is a slow an ad-hoc solution at best. OTL how much dead flat ground defended by earthworks did the French liberate?
By September the BEF has arrived and re-enforced the north of the front around Thionville, a name hallowed by successive generations of British Infantry. The initial British assault to turn the defence line failed but on October 6th 1914 the British broke through and Thionville fell. The British tried to advance toward Saarburg but were soon held well to the west of the Sarre river.
How effective would British offensives, if the Germans have weeks to strengthen their defensive positions? Would the British seriously attempt an offensive?
How does it go from there ?
There would be trenches but not quite as in OTL. It would be more a duel of artillery than sniping with the Germans using the high ground and their defences to hold back the French, British and later American forces. I suspect the British and French would try an outflanking move via Luxembourg at some point but unless the Germans collapse in the East, it seems unlikely there would be a decisive break through. Without the line of trenches there would be more British and French troops to commit to Italy from 1915 and the possibility of fronts opening up elsewhere.
The Germans will secure Luxemburg in almost all possible scenarios, so any flanking move will need to be going through Belgium. I'm not sure how the Russians are expected to collapse a stronger A-H and a greater number of Germans than OTL. I'm also not sure why Italy would want to go up against a stronger A-H, when the Russian starting armies have probably already been busted. The Italian front would rival Gallipoli beaches for daft places to deploy spare Entente troops. Where is the American skin in this game?