U.S. hegemony in West Asia has historically depended not only on material capabilities but also on soft power, political legitimacy, and the ability to construct and sustain dominant strategic narratives. The intensification of Donald Trump’s unilateralist foreign policy, including withdrawal from the Joint Comprehensive Plan of Action (JCPOA), maximum-pressure policies, and support for military actions in the region, has increasingly challenged the credibility of American leadership. Against this backdrop, this study examines the erosion of U.S. soft power and narrative hegemony through the Twelve-Day War between Iran and Israel in June 2025 and the Ramadan War in 2026. The central question is: How did U.S. policies and conduct during these conflicts affect its soft power and narrative hegemony in West Asia? The study hypothesizes that unilateralist policies and the growing gap between U.S. proclaimed values and practices have weakened its legitimacy, credibility, and capacity to shape regional narratives. The two wars are viewed not as the original causes of this erosion, but as critical junctures that exposed and intensified existing weaknesses. Methodologically, the study adopts analysis of official documents, policy reports, public opinion surveys, and regional and international media sources.