I've often wondered about a WW1 stalemate like this, but A-L seems like a dealbreaker for both sides. Colonialism wasn't universally approved of in Germany itself, whereas A-L was a focal point of nationalist rhetoric for both countries.
A WW1 stalemate would likely get resolved, in light of France's belligerence, by the Anglo powers making a relatively under-the-table peace deal whether France likes it or not. That will make the French furious in itself, but ceding French land for that peace deal would be even worse, with or without A-L. The French were in it to win it, and they will not be happy with anything less than a pure victory.
Well unless France is willing to go it alone, she doesn't really have a lot of choice. And frankly, I'm not sure a whole lot of people will care what France thinks when they're looking at sinking poll numbers and no victory in sight.
That's exactly what I'm thinking, and down the line - you've got a very angry France. It's actually quite an interesting case, because there'll definitely be the rhetoric of vittoria mutilata going around but, with A-L, not much irredentism to actually focus on. If the crazies do take power, which is plausible and definitely the most interesting outcome (c.f. basically every German victory timeline), I wonder what their ambitions will be.
They won't get Angola without holding any Portuguese landPerhaps a Germany really wanting peace might evacuate France+Belgium in exchange for the Congo + Angola, but they are not giving back AL.
Say the United States doesn't join world war 1
Would the Entente accept be willing to accept a peace deal which leaves Belgium and Luxembourg alone and cedes Alsace-Lorraine to France in exchange for French colonies