2017-08-06 14:12:16 UTC
Summary of past discussions on WWI timing:
First, generally for the more discussed WWII it's agreed that Germany made its moves in the "sweet spot" of its maximum advantage in '39 and '40. That is, if Germany attacked a year or years early, or if Germany attacked a year or years later, it would have lost quickly and not had the lucky (though unsustainable) run of conquest of Europe in had in OTL.
There is no such consensus on WWI, however, there are ingredients that suggest the "sweet spot" for Germany to launch a war in western Europe in the early 20th century was 1914.
1. The Kiel Canal was ready
2. Austria-Hungary was committed
Also, outside the window, things could be a lot worse for Germany, for instance:
1. If Germany only moves to attack in 1916, 1917 or later, Russian rearmament is more progressed and Russia is too strong for the Schlieffen Plan to have a shot.
2. Germany may be even further behind in the naval race with GB
Or, a big reason cited for why Germany would not have done well to move earlier (1913, 1912, 1911, 1908, 1905, 1885-88 for example)
1. is German dependence in imported nitrates (or phosphates?) for ammunition, prior to the invention of the Haber--Bosch process. [Seriously, take a look at any discussion of an early WWI, especially one based on one of the Morocco crises, and I'll almost guarantee somebody mentions "Haber-Bosch" within ten posts of the OP].
2. The implication of #1 above is that British blockade or interruption of imported nitrates or phosphates (generally from Chile and Nauru) means that Germany can't make new ammunition after 6 months therefore its ability to generate firepower collapse and therefore it loses the war not much later.
3. Other debates center on the comparative strengths of artillery between France and Germany, with some asserting superior French field artillery with a superior rate of fire in any 1905 scenario, and others asserting a German superiority in heavy artillery I think.
So, in summary, some would argue that Germany's window to do as well as it did (and still ultimately lose) was as narrowly constricted to 1914 as it was to 1939.
Now let's consider a factor not usually brought into discussions, the Belgians.
Belgian political attitudes, field forces and fortifications all matter a great deal for any German strike westward into France.
Might Belgium have not resisted like in 1914 if the war had begun in a different year.?
On the one hand, we could say no, after all, no country likes getting invaded, or getting an ultimatum to surrender to occupation, even if (theoretically) it is a temporary occupation.
On the other hand, others attribute to tenacity of Belgium in WWI to King Albert, questioning if his father Leopold would have resisted.
If that's the case, than a Franco-German War (and probable general European War) started in 1875 (the "War in Sight" war scare), 1885-1888 (the peak of Boulangisme, plus eastern crises), 1904-1905 (1st Morrocco), 1908-1909 (Bosnian Crisis) would have seen King Leopold II in charge of Belgium, and perhaps he would have wavered in the face of an ultimatum from the Germans to let them pass through to France.
On the other hand, had 2nd Morocco (1911), Italo-Ottoman (1911-12), 1st Balkan (1912), 2nd Balkan (1913) or Liman Von Sanders Affair (1913) escalated into a general European war triggering the Schlieffen Plan, Albert would have been King of Belgium and thus resisted Germany to the full.
Important as the will of the Belgian monarch may or may not be, how was the resolve of Belgian parliamentary politicians in these various years? And how did Belgium's tools of war, its fortifications, troop numbers and weaponry, compare between the various years? That could well influence Belgium's political will to resist.