My opinion is that there would be no real need for one on the part of the CPs but the Germans are rather stickler legalistic types who likely do weave it in. They declared war upon Russia as a legal point, and perhaps honorable point, based upon the mobilization, rather than more diplomatically letting Russia officially make the first fatal last step to war. But who is at fault? Personally "guilt" is a bit useless really, but the shot first fired was by Serbia in an act of what today we would clearly condemn as terrorism. Russia had given the blessing, thus putting them next in line and France had backed Russia's aggressive foreign policy, including its support for Serbia, so they are co-conspirators. The UK next steps into the dock by backing France. Case closed. If you want to make it dramatic, then Austria contributed by annexing B-H, pushing into the Balkans for more, and Germany conspired to leverage the crime for gain, its invasion of Belgium was not in self-defense but a new crime in the midst of mayhem. And Italy is guilty of picking pockets while things are messy. The USA looting their shops while everyone is away. Japan in another petty thief and the OE should have kept their noses out of other people's quarrels. One can parse it to share guilt or blame right round. But here, if Germany is more than merely undefeated, in any measure victorious, it will pin guilt and demand its pounds of flesh.
A complaint I have in most of these scenarios is about the outrage shown for how "harsh" the CP might be while rather meekly apologizing for the Versailles Treaty or its kin. On one hand the fact is that to the victory goes the spoils, the sad truth is that these nations were in fact barely beyond the feudal, swapping people, territory and treasure like chattel, to lose a war invited execution, slavery and pillage only slightly less brutal than Rome. What Versailles teaches us is that we thought we were better than a vindictive peace, conqueror's privilege and this feudal notion of "woe be the vanquished." And to continue the rant, I am not feeling Germany can do unto the Entente as was done unto them. Very best case, the "peace" in the East gives them breathing room and unwinds the stranglehold of Blockade, even the suggestion of it should cause London to blink. But Russia out is not a magic bullet to victory as OTL proved. The CP are very broken, they cannot outright win. And despite OTL, I do not actually see a B-L, without an inevitable American entry, Russia either concedes or crumbles, Germany grabs some more but shifting West likely grabs less, gaining less, an Offensive in the West being the same gamble, maybe the same last gasp.
The CPs could at best win a stalled and stagnated "victory," France still had its Gold reserves, was industrially producing its arms and had manpower left, what it did not have was the will to conduct any more offensives. The Empire had enough wealth and resources to carry on, the domestic reality was they were edging towards where Germany was getting, an internal break of all the seams holding the thing together, Germany could only achieve a victory if France gave up, something I think was not happening, but it could drive deeper in, costing them more, stretching the British effort to breaking, making any Entente victory utterly hopeless, just a question of what can be salvaged. And even then, the worst case should be some Korea like or split Germany like stalled border, occupied France, conquered Belgium, a cold war like stand off again more like the armistice only end to Korea upon the best line that can be held. Best case is some rational negotiations that unwind three, four or five years of bloody hateful warring, the acceptance that it truly was "all for nothing." More likely we fall somewhere in between. But for some near ASB fall of dominos, the CPs cannot enforce a Versailles style icing of their crappy cake. Our Versailles clothed the Entente in laurels, and in my opinion is why the generation 20 years in future was so demoralized, they saw right through that once they sobered up. Sleights, punishments, guilt and so on would not bring back the dead or repair the soul, it did not restore faith in King, country or even God, this war left enough doubt as to just how noble was the European civilization.
Thus, a guilt clause is rather more window dressing and I think something the CP cannot even hope to hang to fit, the end in a CP "victory" should look far less clean, far more what can be compromised, it will fall to horse trading, bluff, loss and regret, no one gets what they want, they get what they can haggle. And from that it all gets quite fictional, whatever was desired must fall as reality grinds forward. And as always, despite the real weaknesses and problems, the only two powers at play are Germany and the UK, and of the two, in the peace the UK holds one extra card, it alone can remain undefeated, and that means the lens must be what is London willing to give to get Germany to settle, what does London really, really want, what is she willing to lose more to get? That is no British-wank, even at the best outcome, Germany overrunning all of France, Germany is not in position to invade or exploit such a win, and to stop it Britain goes deeper into debt, loss and breakage, as we roll back from such fantasy, the Empire can shape the peace but not dictate it, the subtle truth should be that what comes after relies upon the British being smarter, better and more visionary, London will either found something better or let it all fall through their fingers.
My vision is that the British push Germany back to start, restore Belgium and re-secure France, moderate German gains, offset the design for continental hegemony, weaken her grasp on everything, especially what is developing in Eastern Europe, hoping to break the CP into disunited parts, without giving up more than needed. And that is a rather flexible blank page, barely any lines to color within, a grossly variable future. I doubt that East and West Germany or North and South Korea were how any of the powers wanted to wrap up those wars, the early deals never meant to solidify, lines drawn, sides taken, nothing was as it was meant to last decades but that was how two wars ended with each side victorious enough, undefeated enough, willing to cease fire, intending to settle it more to their liking yet ending with a bodge. As unsatisfying as it reads, the better ATL will be a bodge, messier and less predictably settled than OTL, even the veneer of victory and justice and punishment will be missing, and perhaps that is what the war of 1914 - 1918 needed, not even the pretend that it was Great because it was for something greater.
A complaint I have in most of these scenarios is about the outrage shown for how "harsh" the CP might be while rather meekly apologizing for the Versailles Treaty or its kin. On one hand the fact is that to the victory goes the spoils, the sad truth is that these nations were in fact barely beyond the feudal, swapping people, territory and treasure like chattel, to lose a war invited execution, slavery and pillage only slightly less brutal than Rome. What Versailles teaches us is that we thought we were better than a vindictive peace, conqueror's privilege and this feudal notion of "woe be the vanquished." And to continue the rant, I am not feeling Germany can do unto the Entente as was done unto them. Very best case, the "peace" in the East gives them breathing room and unwinds the stranglehold of Blockade, even the suggestion of it should cause London to blink. But Russia out is not a magic bullet to victory as OTL proved. The CP are very broken, they cannot outright win. And despite OTL, I do not actually see a B-L, without an inevitable American entry, Russia either concedes or crumbles, Germany grabs some more but shifting West likely grabs less, gaining less, an Offensive in the West being the same gamble, maybe the same last gasp.
The CPs could at best win a stalled and stagnated "victory," France still had its Gold reserves, was industrially producing its arms and had manpower left, what it did not have was the will to conduct any more offensives. The Empire had enough wealth and resources to carry on, the domestic reality was they were edging towards where Germany was getting, an internal break of all the seams holding the thing together, Germany could only achieve a victory if France gave up, something I think was not happening, but it could drive deeper in, costing them more, stretching the British effort to breaking, making any Entente victory utterly hopeless, just a question of what can be salvaged. And even then, the worst case should be some Korea like or split Germany like stalled border, occupied France, conquered Belgium, a cold war like stand off again more like the armistice only end to Korea upon the best line that can be held. Best case is some rational negotiations that unwind three, four or five years of bloody hateful warring, the acceptance that it truly was "all for nothing." More likely we fall somewhere in between. But for some near ASB fall of dominos, the CPs cannot enforce a Versailles style icing of their crappy cake. Our Versailles clothed the Entente in laurels, and in my opinion is why the generation 20 years in future was so demoralized, they saw right through that once they sobered up. Sleights, punishments, guilt and so on would not bring back the dead or repair the soul, it did not restore faith in King, country or even God, this war left enough doubt as to just how noble was the European civilization.
Thus, a guilt clause is rather more window dressing and I think something the CP cannot even hope to hang to fit, the end in a CP "victory" should look far less clean, far more what can be compromised, it will fall to horse trading, bluff, loss and regret, no one gets what they want, they get what they can haggle. And from that it all gets quite fictional, whatever was desired must fall as reality grinds forward. And as always, despite the real weaknesses and problems, the only two powers at play are Germany and the UK, and of the two, in the peace the UK holds one extra card, it alone can remain undefeated, and that means the lens must be what is London willing to give to get Germany to settle, what does London really, really want, what is she willing to lose more to get? That is no British-wank, even at the best outcome, Germany overrunning all of France, Germany is not in position to invade or exploit such a win, and to stop it Britain goes deeper into debt, loss and breakage, as we roll back from such fantasy, the Empire can shape the peace but not dictate it, the subtle truth should be that what comes after relies upon the British being smarter, better and more visionary, London will either found something better or let it all fall through their fingers.
My vision is that the British push Germany back to start, restore Belgium and re-secure France, moderate German gains, offset the design for continental hegemony, weaken her grasp on everything, especially what is developing in Eastern Europe, hoping to break the CP into disunited parts, without giving up more than needed. And that is a rather flexible blank page, barely any lines to color within, a grossly variable future. I doubt that East and West Germany or North and South Korea were how any of the powers wanted to wrap up those wars, the early deals never meant to solidify, lines drawn, sides taken, nothing was as it was meant to last decades but that was how two wars ended with each side victorious enough, undefeated enough, willing to cease fire, intending to settle it more to their liking yet ending with a bodge. As unsatisfying as it reads, the better ATL will be a bodge, messier and less predictably settled than OTL, even the veneer of victory and justice and punishment will be missing, and perhaps that is what the war of 1914 - 1918 needed, not even the pretend that it was Great because it was for something greater.