Widespread displacement of persons domiciled in northeastern Nigeria is one of the most profound aftermaths of the Boko Haram insurgency. This study investigates the challenges of internally displaced persons (IDPs), particularly women and girls, in northeastern Nigeria. The focus is primarily on the United Nations' (UN) interventions and reintegration policies as the "government of the world," the implementation of these policies in the Nigerian context, and their effectiveness for women and girls. The study asks the following questions: What are the general and gender-specific challenges of IDPs in northeastern Nigeria? How have the UN intervention and reintegration processes responded to those challenges? How gender-sensitive are the UN's intervention and reintegration processes for Nigeria's female IDPs in that part of the country? The researcher applied internationalism and a feminist perspective on human security as the conceptual framework for this study. Interpretative phenomenological research methodology was used to investigate this phenomenon through in-depth individual interviews, focus groups, and observation of participants and camps. Twenty-four individual interviews were conducted with 12 IDPs and I2 officials. Four focus-group discussions were also facilitated with 28 participants. Thematic analysis of data was achieved using interpretative phenomenological analysis in a four-cycle coding process, resulting in 3 themes [the general and gender-specific challenges of participants; internationalism and UN interventions for Nigerian IDPs; and UN interventions; gender blind]. This study, which included the shared experiences of participants resulted in informed recommendations at the conclusion of the thesis. Major recommendations suggest improvements in the subsistence interventions and reintegration processes of this region with special attention to the gender needs of the displaced women and girls.