A large share of the Afghan fighters that constituted the ground forces in the 2001 US-led intervention in Afghanistan were returning from exile. Militant groups operating in refugee environments were integral to any understanding of Afghanistan’s conflicts. Yet, there was no debate of the possible challenges of staking an intervention, and subsequently, a new regime, on militant groups returning from abroad. Using the return in Afghanistan post-2001 onwards as an example, this policy brief casts light on militant returns. Armed groups use the unique qualities of exile environments to build organization, develop a resource base, and garner support by offering security, while socializing fighters and supporters alike. We look at the long trajectories of armed groups in exile, which often include roots that predate the exile, and likewise continuities that survive return with important effects on their accommodation. The immediate implication is to acknowledge the challenges of return from militarized exile environments. Each case is different, calling for a fine-grained analysis of the constitution of the groups, the political context, and possible post-return scenarios. As a consequence, states, multilateral agencies, and other actors will need to look at the interaction between refugee return and a number of other measures, such as demilitarization, political participation, or economic sustenance. Sustainable return is an important goal in all peace processes, but peace and stability, as well as return and reintegration, will be much more likely when the underlying tensions are acknowledged and addressed.