Protracted displacement has placed refugees and host communities into sustained proximity across much of sub-Saharan Africa, the Middle East, and South Asia, raising the question of what conditions allow the two groups to coexist peacefully rather than descend into rivalry over land, livelihoods, and public services. Drawing on the Ager and Strang conceptual framework of integration and on intergroup contact theory, this article examines how economic, social, psychosocial, legal-institutional, and spatial dimensions of integration jointly shape the quality of relations between displaced populations and the communities that host them. Using a targeted narrative synthesis of peer-reviewed studies and authoritative institutional reports, with priority given to recent empirical work and earlier foundational sources retained for theory, the analysis draws evidence from Kenya, Uganda, Ethiopia, Bangladesh, and Lebanon. It argues that peaceful coexistence is rarely the product of a single intervention but instead emerges from the cumulative and mutually reinforcing effect of several integration domains operating together. Economic inclusion reduces competition over scarce resources but is insufficient on its own; social contact under favorable conditions builds trust but can also expose latent threat perceptions when poorly managed; psychosocial wellbeing programming addresses the human costs of displacement that would otherwise erode goodwill; and secure land tenure arrangements prevent the disputes that most reliably escalate into open conflict. The article concludes that policy and programming should treat integration as a multidimensional and sequenced process, with attention to how gains in one domain can be undermined by neglect in another, and offers implications for practitioners and policymakers working in protracted refugee-hosting contexts such as Kenya's Kakuma and Dadaab camps.