What most of you are failing to recognise is that Schlieffen's Grand Memorandum of 1905-06 was not a strategic plan approved by the German General Staff and issued to the army commanders.
Rather, it was a purely hypothetical exercise written by Schlieffen just after he had retired as Chief of the General Staff, having as its theme how Germany could defeat France if it were fighting a single-front war against that country alone, with no involvement by Russia, and if it possessed and army much larger than it actually did possess in 1905, or even in 1914. There is no hard evidence that it was ever accepted as an actual war plan, although Moltke did look at it in 1911 and wrote some comments on it.
It also needs to be remembered that the Grand memorandum remained entirely secret until the 1950s, when the German historian found it in the US National Archives, where it had been deposited after being seized with a lot of other material from the German archives at the end of the Second World War, and published it.
Ritter thought that he had discovered the actual war plan implemented by the German Army in 1914, but the fact is that nobody knows exactly what that plan was since the only full copies of it, stored in the Reichsarchiv in Berlin, were destroyed in a bombing raid in 1945. The only preserved parts of the plan are those covering the operations of the Bavarian Army on the German left flank, which were stored in an archive in Bavaria.
Since the Allies did not occupy Germany at the end of the First World War, they never gained control over the German archives, with the result that the German Government was able to keep its war plans for 1914 and previous years secret, locked away in the Reichsarchiv. Although in the interwar period German military historians published histories of the operations of the German forces during the First World War, the actual operational plan of 1914 was never published in full.
Although the full operational plans for 1914 and preceding years are no longer extant, it has proved possible to reconstruct them from fragmentary records of war games carried out during those years, and more particularly from an unpublished summary of pre-1914 planning (but not the 1914 plan) prepared in the 1930s by someone who had access to the copies of the plans stored in the Reichsarchiv; that summary was captured by the Soviets in 1945, stored in Moscow as war booty, and then returned to Germany after the collapse of the Soviet Union.
From those sources it has been possible to deduce that the German operational plan in each year leading up to 1914 had four variants:
1. for a single-front war in the West only;
2. for a single-front war in the East only;
3. for a two-front war in both West and East, with the concentration of forces in the West;
4. for a two-front war with the concentration of forces in the East.
In any given year, the variant of the operational plan that was given emphasis depended on the objective situation in that year. In 1914, the German High Command was apparently implementing the third variant above, for a two-front war with the concentration of forces in the East.
Since Schlieffen's Grand Memorandum of 1905-06 described a hypothetical war against France alone, it was relevant only to the first variant of the operational plan, and it is obvious that the German armed forces cannot have been trying to implement the concepts of the Grand Memorandum in 1914 since they were fighting a two-front war, not a war against France alone.
The actual movements of the German armed forces in August 1914 do bear a superficial resemblance to some of the hypothetical actions described in the Memorandum in that those forces did move through Belgium, but the move through Belgium was not an invention of Schlieffen in 1905. It had in fact been part of German planning since the 1890s, when the concept of a swift movement through the south-eastern corner of Belgium, moving to the east of the Meuse River, for the purpose of getting in behind the line of French frontier forces and encircling the French forces on the frontier, was incorporated into German operational planning.
Bear in mind that Germany had originally demanded that Belgium grant free passage for German forces through its territory. If that demand had been granted, it is likely that the German forces would have moved very quickly up the valley of the Meuse and been able to catch the French forces assembled on the frontier for the planned invasion of Lorraine before those forces could have moved back to the west to escape the trap.
As it was, the German forces were held up for several days trying to reduce the fortifications around Liege, so they were only able to begin their movement en masse through Belgium at around the same time as the French forces began their invasion of Lorraine. Thus, by the time the German forces had won the Battle of the Frontiers and forced the British and French forces out of Belgium and back into France, the French forces that had invaded Lorraine were already moving back toward Paris. It was at that point that Moltke decided to his advance toward Paris, which probably had not been part of the original German operational plan.
This is Zuber's reconstruction of the German strategic plan of 1914, in his book "The Real German War Plan 1904-14":
Pages 147-148:
The German war plan in 1914 was relatively simple. It followed Schlieffen's counter-attack doctrine. In the west, the German army would deploy on a broad front to make maximum utilisation of the rail net and the available space for manoeuvre. It would then find the French main body, move against it, and defeat it as quickly as possible. The French army would withdraw to next defensive position. The Germans would probably use this pause in the west to transfer up to seven corps to the east for a counter-attack there.
In the east the Germans would be outnumbered 2:1, but would use their interior position to mass against one of the two attacking Russian armies. If necessary, the Germans would fall back to the Vistula fortifications. The Central Powers' Achilles heel was the Austrian army, which was weak and outnumbered 2:1.
The German advantage lay in its interior position and rail mobility - the ability to mass on one front, win, and then mass on the other. This would make optimal use of German tactical and operational superiority over all of its opponents. This ability is known today as a "force multiplier" and was the sole means the Germans had of offsetting their numerical inferiority. Such a strategy would not produce strategic victory, but successive defeats of French and Russian armies would destroy their capacity for offensive action.
A German strategic offensive deep into the interior of either enemy territory negated the German advantages of interior position and rail mobility; indeed, the rail mobility advantage would pass over to Germany's opponent. A German strategic offensive, such as the one Moltke launched into France on 24 August, after he had won the Battle of the Frontiers, was a gamble that Germany had the means of winning an immediate victory on one front.