This research brief delves into the decentralised and community-driven reintegration of formerly armed actors (FAAs), shedding light on its potential role in sustainable peacebuilding efforts and local ownership. Illustrated by case studies from Ukraine, Northern Ireland and Sub Saharan Africa, the Brief highlights the significance of decentralising administration and decision-making processes for reintegration programs. By empowering local and community levels, this approach may not only boosts efficiency and participation but also fosters broader social and economic development objectives. It also discusses existing empirical evidence of decentralisation success and possible challenges of decentralisation like increased corruption, coordination challenges or ethnic seperatism. Finally, the Brief presents a case study on the coupling of FAA reintegration and territorial development policies in Colombia.