This document is a dissertation that examines the relationship between horizontal inequalities and nationalist violence using African Americans in the United States as a case study. It argues that blaming Black nationalist groups for recent violence is incorrect, and that systemic horizontal inequalities are the true cause. The dissertation will analyze economic, political, social, and cultural data on conditions facing Black Americans to demonstrate these inequalities. It aims to directly link horizontal inequalities to the emergence of nationalism and violence, showing that a lack of development and strong racial inequalities have become security issues in the US.