Johnson, a historian at Oxford University, deals with the subject of Sudan's tragic civil war as an outsider, yet he reveals a profound knowledge of Sudan's internal, regional, and international politics. Anyone wishing to learn more about the Sudanese tragedy should read this scholarly study, written in simple and clear language. In all of Johnson's books—his prior ones include Nuer Prophets  and co-authorship of Operation Lifeline Sudan (OLS): A Review —he deals with the Sudanese conflict through the prism of history, aware of how current conflicts are rooted in the nineteenth century.
It was then, beginning in the 1820s, that the army of Muhammad ‘Ali, the Ottoman-Egyptian ruler, captured the Arab Muslim northern region of what later became known as the Sudan. His forces, intensively assisted by Arab Muslims from the north of Sudan, soon raided the south of Sudan, enslaving its non-Muslim people and draining their living resources. This was the first massive, bitter encounter between people from the north and south of Sudan, setting the foundations for further antagonism.
The Root Causes of Sudan's Civil Wars is mainly devoted to a discussion of the historical structure of north-south relations throughout Sudan's modern history. Most noteworthy among them are the 1972 Addis Ababa peace agreement and the regional government, and the rekindling of what he calls the second civil war since 1983. Johnson also refers to current issues of the armed conflict in Sudan, such as the impact of religion and race and the role of foreign relief agencies and international Islamist networks in shaping the course of the war and prospects for peace. He correctly observes that the prospects of ending Sudan's armed conflict seem gloomy, stating that Sudan "entered the twenty-first century mired in not one but many civil wars."
The author correctly notes that what had been seen in the 1980s as a war between north and south— namely Muslims against Christians, and Arabs against Africans—has after nearly two decades of armed hostilities, broken the bounds of any north-south conflict. Johnson further argues that not only are Muslims now fighting Muslims (as illustrated by the outbreak of the armed rebellion in western Darfur against the Khartoum government), but also Africans are fighting Africans.
 Oxford: Clarendon, 1994.
 Geneva: United Nations, Department of Humanitarian Affairs, 1996.