The new UN Secretary-General, António Guterres, has made prevention his top priority. Conflict prevention is now understood not only in terms of averting the outbreak, but also the continuation, escalation and recurrence, of conflict.* The Secretary-General has recognized that in order for the UN to shift from its current, largely reactive, posture to a prevention-oriented approach, it will need to better integrate its peace and security, development and human rights pillars of work.† Sustaining peace and sustainable development will need to work hand in glove, rather than along two separate tracks as has often been the case in the past. In an effort to help shift the system toward this new approach, the UN and the World Bank are undertaking a joint flagship study on Preventing Violent Conflict. This thematic paper on preventing violent urban conflict was produced as a backgrounder for the UN-World Bank study.