This paper summarises our state of knowledge regarding diaspora engagement in conflict societies. It presents a map of possible diaspora contributions and their specific potential positive and negative impacts in societies experiencing or recovering from conflict. Following a discussion of diasporas and their motivations for engagement in their places of origin, the paper reviews the specific remittance, philanthropy, human capital and policy influence contributions, both positive and negative, that diasporas may make. Policy implications include the need more systematically to include considerations of diasporas in conflict/post-conflict interventions, and based on a more careful case-by-case analysis, using the provided map as a starting point. Such analyses can inform decisions of when to tolerate, unencumbered, diaspora engagement; when to facilitate or support such engagement; and when to consider strategic partnering with diaspora efforts. By mapping potential positive and negative influences of diasporas, the paper establishes why a more nuanced understanding of diasporas and peace and conflict is so important to policy and practice for a more peaceful world.