Although the Iraqi government declared their military campaign against ISIS concluded in 2017, and the Pentagon officially acknowledged this in 2019, the United States has maintained its military presence in Iraq. This study examines the underlying motives behind the continued U.S. involvement in Iraq under the justification of "fighting ISIS." Adopting a critical perspective on national interest, it explores the intersection between U.S. strategic objectives and the agendas of powerful economic actors, while situating this within the broader geopolitical landscape. Employing qualitative methods, the study analyzes secondary data from journal article, books, online media, news sources, and official government reports. The evaluation of U.S. national interest focuses on three key dimensions: security, economy, and politics. In terms of security, the U.S. has struggled to establish long-term stability in Iraq or to enhance regional safety, particularly in light of intensifying rivalries with regional powers such as Iran and Turkey. Economically, while the U.S. invested significant taxpayer funds in the conflict, the primary beneficiaries have been major oil and defense corporations, reflecting the entanglement between foreign policy and corporate interests. Politically, U.S. influence in Iraq has waned, challenged by both growing domestic opposition and the expanding geopolitical footprints of competing actors, notably Iran, Russia, and China. Given these findings, the study argues that the United States must reassess whether its ongoing military engagement in Iraq aligns with its broader strategic interests amidst the shifting geopolitical dynamics of the Middle East.