Editorial on the Nigerian Civil War

Here is a link to an editorial in the British newspaper The Guardian.
http://commentisfree.guardian.co.uk/rosa_davis/2007/09/biafran_lessons.html
It discusses the Biafran War (sometimes called the Nigerian Civil War) and how this conflict, 40 years ago this year, is emblematic of the way European-drawn borders have encouraged conflict between ethnic groups in Africa. Several of the responses to the editorial raise the question of why do we call African groups like the Ibo "tribes" and not apply that term to European groups like the English, French, etc.