Belgium has it's fair share of riots during the transformation from a parliamentary monarchy to a federal monarchy. Many towns were disputed and still are ...
The only reason because it's been peaceful is because of the high level of civilization, but in the north the seperatist far right party gains 3 to 5 % every election. A new transformation to complete confederation or even 2 nations (perhaps with a fusion of Wallonia/France and/or Flanders/Holland) looks very likely within 20 years.
Especially the large mentality, culture, language and economic differences are a katalysator for a further splitting of the country. For instance, unemployement is about 10 % higher in Wallonia, the GDP of Flanders resembles that of the USA per capita, the Walloon GDP resembles that of Portugal per capita... annually, there have been financial transfer from the northern Flemish area to the southern Walloon area of no less than 8 to 11 billion euro's, or 2000 per Flemish inhabitant per year.
The only glue that kept the country together so far, is the bilingual capital Brussels, no one knows what to do with that city and who it belongs to. If Brussels wasn't bilingual or wasn't the capital, Belgium would have followed Czechoslavakia already...
It's a matter of time.