This chapter describes key debates and future challenges in the field of youth, peace and security. The United Nations Agenda on Youth, Peace and Security emerged from more than a decade of global advocacy by civil society, youth-led organizations, non-governmental organizations, governments, and intergovernmental organizations. It responded to major trends and events in world politics, such as those noted above, but it also built on prior research on children and youth and normative global commitments to young people’s rights. The literature on youth combatants overlaps with the large number of child soldier studies and includes local ethnographic studies, and studies focused on reintegration and psycho-social interventions with former young combatants. Neoliberal ideals reinforce understandings of youth as proto-citizens, seeing post-conflict reconstruction and peacebuilding priorities for youth through limited economic frames that limit capacity to recognize youth’s active agency.