The cost? With The entire German Empire fighting an outnumbered France, the cost wouldnt be that high. Especially not if you could persuade Britain to join
Yes, because France will promptly forget about the fact Belgium did that after signing over this area of territory. Britain will continue to see Belgium the same way as OTL . . . absolutely no long term consequences.
Yeah, no. Say hello to Belgium having to hope and pray that France has bigger problems, and find a big anti-French, probably pro-German (if not Germany itself) ally to protect its seizure of this area.
Britain is not going to support Belgium here unless Anglo-French hostility gets much worse than OTL. Either in the short term or the long term.
So if we have a WWI like OTL (your butterfly-free scenario), Belgium won't be getting pieces from Germany, Belgium will be forced to give this back to France the same way things were taken
from Germany.
The Rewards? one of France's most important Industrial areas; the most heavily populated department of France; France's only coal mines; Lille, Douai, Cambrai and Valenciennes as important cultural areas; 2 extra universities in Lille and Douai; France's third-largest harbor Dunkirk
Also: And France will agree to give this up why?
Belgium doesn't have the muscle to do it on its own, and Germany has no reason to want it given to Belgium - those concerned with it being too much to demand it for Germany are trying a softer peace than OTL, those not concerned will not want it going to someone else.
It's not impossible, but it doesn't seem very likely.
Nop, I just wanna make a Belgiumwank... If someone gives Alsace, Lorraine and Burgundy to Germany in a Germanwank or Normandy and Brittany to Britain in a Britwank nobody says anything. But make Belgium greater and you unleash the fury of the internet upon you it seems...
People regularly "say something" in regards to Germanwanks or Britwanks. And I hardly think that people pointing out Belgium is not in a good position to be wanked is furious hostility.