From “Burundi: How to Deconstruct Peace“, November 2015:

 In truth, the success of Burundi’s peaceful transition was overstated to begin with. The implementation of the Arusha agreement was both unfinished and undesired by the government. The ruling party… even blocked the implementation of several conditions, including, most prominently, those related to the creation of a special tribunal to judge the crimes of the civil war. Consequently, nobody has answered for these and Burundi has failed to move past them…

The return of authoritarian and corrupt governance to Burundi has been made possible because the guarantors of the Arusha agreement did not follow through on their commitments. They ignored early warnings about the return of authoritarian governance and that peace was beginning to unravel. Peacebuilding requires a long-term political engagement to have any degree of success. This is something that those seeking an end to the current Burundian crisis must bear in mind if they are to achieve more than a brief interruption of the country’s fighting and instability.