Mass migrations resulting from war, insecurity, and economic crises generate a complex set of cultural, identity, and institutional challenges for both immigrants and host countries, with immigrant access to information and library services representing a frequently overlooked dimension. The concept of "diaspora," denoting the dispersed population of a country residing elsewhere, highlights that migration is not merely a demographic relocation, but is instead intertwined with issues such as identity fragmentation, generational gaps, the preservation of mother tongues, weak cultural adaptation, and limited connection with the home country. In Iran, Afghan nationals constitute the largest resident immigrant group; simultaneously, the absence of precise statistics, the dominance of a security-oriented approach, and a lack of coherent planning have left the latent capacities of immigrants underutilized. Under such circumstances, public libraries can play a vital complementary role in narrowing the educational divide and strengthening cultural adaptability. Policy strategies include ensuring free and easy immigrant access to libraries, establishing participatory libraries in immigrant-dense neighborhoods by leveraging the capacities of the immigrants themselves, training and employing talented immigrants in librarianship, providing specialized information resources for immigrants, developing mobile and cross-institutional services, and designing cultural programs to foster social coexistence and preserve immigrant identity. Furthermore, shifting the governance approach from a security-oriented framework to a socio-cultural one and establishing specialized mechanisms for migration policymaking are deemed essential prerequisites.