Shall we blame the Brits for Sunni and Shiia slaughtering each other for hundreds of years too?
Mainly yes.
Ever looked at a 'natural' map, like Europe, Asia etc?
And ever looked at an 'artificial' map, like USA, Africa?
Do you notice a difference? Most borders in Africa are artificial. Straight lines going through old 'tribes' territories, splitting up stuff that 'belongs together' and add 'random' areas to now existing countries.
E.g Texas in the USA, several straight borders, same for Libya, Algeria, Sudan etc. in Africa.
Basically everything that is running bad in Africa is a direct result of european imperialism.
The whole continent was still 'sone age' or early 'iron age' when the occupiers finally left.
But now a tribe had tanks, the other had not. The guys ruling there usually do one thing: 'cleanse' the previous ruling cohorts and replace every post with family members and far relatives. Regardless if they win an election or become rulers by a coupe. The idea that law is above everything, that corruption is bad etc. etc. is a strange concept to them. How should it not, during the occupation by europeans they experienced that the laws are not protecting them, they are only to the benefit of the imperialists.
There is plenty of literature about Africa around 1900 ... good movies, too. Even random 'novels' which made it to movies give good back ground knowledge, or at least an impression.
In roman times, and even when the british conquered half of it, Africa was full with empires, striving huge empires.
But the British did it like the Romans: befriend one tribe, give him 'modern' weapons and let him lose on the 'enemies' of that tribe. With the promise to support that tribe with houses, more weapons, schools, and most important: churches.
They did the same in India and New Zealand ...