In <i>From Migrants to Refugees</i> Jill Rosenthal tells the history of how Rwandan migrants in a Tanzanian border district became considered either citizens or refugees as nation-state boundaries solidified in the wake of decolonization. Outlining the process by which people who have long lived and circulated across the Rwanda-Tanzania border came to have a national identity, Rosenthal reveals humanitarian aid's central role in the ideological processes of decolonization and nation building. From precolonial histories to the first Rwandan refugee camps during decolonization in the 1960s to the massive refugee camps in the 1990s, Rosenthal highlights the way that this area became a testing ground for novel forms of transnational aid to refugees that had global implications. As local and national actors, refugees, and international officials all attempted to control the lives and futures of refugee groups, they contested the authority of the nation-state and the international refugee regime. This history, Rosenthal demonstrates, illuminates how tensions between state and international actors divided people who share a common history, culture, and language across national borders.