The Central Powers Win WWI.

[Susano]

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What you want is WJB: a President who will resign before he declares war on Germany.

Sounds good
Alternatively:

If unrestricted submarine warfare never begins because Germany is confident of victory to the point of offering a peace among equals in the West then Wilson probably isn't going to be able to get the US involved.

If Italy is on CP side the war is most likely over before the whole sub warfare thing can blow over... I dont think Germany would ever forego it. They needed to have a counter to the British surface blockade, which was after all just as inhumane and illegal. But the war could be over quick enough before the submarine warfare causes problems.

Right now I'm considering the change being 1915, too late to stop Italy from selling itself to the highest bidder but early enough to keep the US and many smaller powers from joining the Entente, especially with Russia visibly failing before countries like Greece and Romania would have entered the war.

Of course, problem with that is that it needs Germany to concentrate on Russia, and that needs a reason...

but which gives Germany the moral high ground as it is clear to all that the British and French can't expect to win while Germany might but Germany is not only offering to let them off but even give up on all the German colonies save East Africa.

Oh, no way thats happening with Wilhelm II or Hindenburg (the de facto power in Germany IOTL in the late war, though with an easier war for Germany it most likely doesnt come to that) will allow that. Though, thats not bad per se - one problem with Germany victorious in WW1 is how that would reconfirm the reactionaries and militarists. Here, by insisting on continuing the war they will draw the ire of the population, so we might see a German republic or constitutional monarchy even while victorious, which is always a good thing...

I think you need an early victory. Germany suffered too much from the British blockade in 1917/18.

Yeah, well, but that goes also vice versa: The submarine warfare was very effective against the UK, too. If there had not been that one interruption from it, then it might even have forced the UK to the negotiation table...