Lists of African success stories do not tend to include Chad. More than half of the country’s citizens live below the poverty line. According to data collected by the United Nations, most have spent less than two years at school. From 2008 to 2010, the European Union and U.N. deployed peacekeepers to the country’s unstable eastern border with Sudan. At one point, rebels managed to assault the capital, N’Djamena.

Yet this year, Western powers and the U.N. have turned to Chad to help manage new crises in Mali and the Central African Republic (CAR). The supposed basket case has suddenly emerged as “a new regional military power,” as Arthur Boutellis has noted, and can now claim to be “a credible African voice.” Last month, it easily won a seat on the Security Council. But if Chad’s rise to prominence as a military player has been rapid, it has also been ugly. It is a perturbing testament to the lack of more-credible alternative peacekeepers and symptomatic of flaws in Africa’s collective security system. ...