Your challenge is: to create a scenario where wars of dynastic succession are still extant in the year 2012 CE.
The most important thing hat must happen is to let monarch retain their powers. Currently it doesn't matter who is king (or queen) of the UK, the Netherlands, Belgium, Luxemburg, etc, as the true power in those countries lie with the democratically elected politicians. So why would Britain care who becomes the next king of the Netherlands, as it will be the Dutch prime-minister that actualy rules the country.Your challenge is: to create a scenario where wars of dynastic succession are still extant in the year 2012 CE.