Sudan always was an improbably huge result of post-colonial border invention, and the near-permanent civil war between the country's north and south ever since seems evidence enough that this split is a good idea. Certainly the South Sudanese think so.
But it's got a potentially huge peace dividend for the world as well. South Sudan is the last refuge of one of humanity's oldest diseases, guinea worm. People drink the worms' larvae in stagnant water, then a year later the adult worm emerges through the skin, so painfully that the victim immediately plunges the affected area into... the nearest pond. The worm instantly releases its eggs and the cycle continues.
There are no drugs and no vaccine. So the only way to stop this is to keep each and every person with a worm from putting it in water sources - and to kill worms in ponds with pesticide, and give people filters for drinking water. Clean wells are the ultimate, but the geology of South Sudan - as well as poverty and war - makes them difficult to drill there.
