Since 2003, the international community has invested considerable resources in keeping the peace in the Democratic Republic of Congo (DRC). Many interventions were focused on supporting security sector reform (SSR) and on the stabilisation of the volatile ‘militia belt’ in the eastern DRC, but these only achieved limited impact and the security context remains volatile. To explain why international efforts did not bring about the expected changes, the authors examine issues such as the peculiar relationship between the armed forces and local communities, and the neopatrimonial incentives of the Congolese elite. A largely technical approach that ignored the bigger political picture underscores the failure to fundamentally change the DRC’s security context. The defeat of the M23 rebellion in 2013 was a rare success, but it now threatens to take away the necessary pressure for meaningful reform.