Why didn't Belgium get more land after World War One?

Belgium didn't get more land after World War One due to several reasons: 1. The territorial changes were based mostly on demographic lines. 2. The foundational principle of self-determination - the majority of people in the areas Belgium claimed didn't see themselves as Belgians. 3. Belgian diplomats often couldn't agree on what they wanted. 4. Their excessive demands offended their allies. Despite these, Belgium did gain some lands in Africa and parts of Germany.

via Why didn't Belgium get more land after World War One? (Short Animated Documentary)