Not being an expert or scholar on African, or indeed much other, history it seems to my simple brain that a couple of very obvious factors behind this problem could well be overpopulation, leading to competition for land, food, water, religion and tribalism.
Most boundaries/borders of many countries, not all in Africa, were drawn up by colonists and hence the land areas so included have people of differing cultures and languages. Most of these differing peoples have been at war with each other for centuries. What makes people think that all of a sudden everything turns to goodness and light.
New Guinea is a good, close to home, example.
Australia, where we pride ourselves on being "civilised", has more than its fair share of co existence issues.
What hope has a country with a history of actively suspicious people have.

Biafra did not manage to sustain its independence. If it has problems today, they are not due to pursuit if independence but to reintegration into Nigeria.

For all South Sudan’s woes, I doubt many South Sudanese want to return to rule from Khartoum. The brutality of that regime and the things it inflicted on its southern population beggars belief. I know some of the refugees that came to Australia to escape that conflict. Their stories are heartbreaking.

Many other countries have seceded successfully – Finland, Ireland, Singapore. East Timor has many challenges but seems to be doing ok.

The author seems to be spinning a line to support the Malawi government’s position against the secession of North Malawi. Whatever the merits or otherwise of that particular case, it is not true that secession always fails.

Hear, hear, Rhian, and well said!
Rhrosty.

Tribalism is the main problem. The colonizers failed to recognize this and set up artificial states without due regard.
I attended a meeting put on by the Victorian Corporate Affairs Department a few years ago. We were told that in Victoria there were about eighty different incorporated association of people from Africa. They all hate one another. How can democracy succeed in any country where this is so. This applies in many other areas of the including the Middle East.

David