The treaty gave the South six years of autonomy followed by a referendum on independence, which saw 98.83 percent of South Sudanese voting for independence and just 1.17 percent voting against it. Then, on July 9, 2011, the nation of South Sudan was created.
South Sudan was born out of conflict; 2 million people died in the Second Sudanese Civil War and 500,000 people died in the First Sudanese Civil War.
The conflict between the North and South was simple.
The formally united country of Sudan was created in 1946 when British colonists decided to merge two regions that had no business being a single country.
Inevitably, the South rebelled against the domination of the North. And they kept at it until they finally received their independence in 2005.
The difference between the North and South isn't just an issue of circumstantial conflict, like the US Civil War.
The US North and South, for example, had differences in their economic interests, belief on the issue of slavery, and mild culturally differences. However, both populations essentially had the same language, religion, ethnicity, and similar cultures.
Even so, those circumstantial differences were big enough to cause the biggest loss of life in American history.
Meanwhile, the North and South in Sudan already struggled with circumstantial conflicts like appointments to government posts. In addition to that, there were vast differences in ethnicity, culture, religion, and language.
History has shown that slapping together a country that should be split roughly evenly into two usually doesn't work. That's not to say that a nation has to be homogeneous; however, a pluralist society usually consists of one clear majority and many smaller minorities.
Or, the cultural, religious, and ethnic differences between the majority (ruler) and minority (subject) isn't too vast.
In the early 20th century, Africa was plagued by Europeans ruling Africans, which clearly was unsustainable. When the Europeans left, however, they drew national borders that often grouped together two extremely different groups.
Since then, many parts of Africa have been plagued by vicious wars; nearly all of them involved groups with at least different ethnicities, if not different cultures and religions.
So will the splitting of Sudan bring lasting peace? Only time will tell, but at least the situation isn't a ticking time bomb anymore.
Should other African countries also split into two? Should the whole map of Africa be redrawn along ethnic lines?
Over time, the lines of Africa will indeed be drawn roughly along ethnic lines.
Whenever there is a dramatic shakeup in the geopolitical landscape of a region - usually the leaving/breaking up of a great power or emergence of a new power - new acceptable borders will be drawn, although it usually takes a long time.
When the Roman Empire fell, for example, it took Western Europe hundreds of years to flesh out its borders; the region of Alsace and Lorraine alone (currently under French control), for example, have been fought over and changed hands countless times.
Africa is simply the latest victim of this process. Hopefully, with everything the human civilization has learned over the last few thousand years, Africa can flesh out its borders in a more peaceful manner in the 21st century.