The fall of Bashar al-Assad's government, one of the major geopolitical developments in the Middle East, has significantly impacted the regional balance of power and the pattern of Iranian-American rivalry in Iraq. For years, Syria served as a strategic ally of Iran within the Axis of Resistance, and the collapse of the Assad government transformed this geopolitical linkage. At the same time, the United States sought to turn this development into an opportunity to reduce Iran's regional influence. Against this backdrop, the present study aims to analyze the implications of Assad's fall for the pattern of geopolitical rivalry between Iran and the United States in Iraq, and to examine its repercussions for Baghdad's foreign policy. The central research question is: How has the fall of Bashar al-Assad's government affected Iranian-American rivalry in Iraq? The study hypothesizes that, following the collapse of the Assad government, Iran will focus more heavily on maintaining its regional position through its influence in Iraq, thereby intensifying competition with the United States there. This study adopts a descriptive-analytical approach and relies on library-based data collection. The findings indicate that, in the post-Assad period, Iraq has become a multilayered arena of Iranian-American competition, encompassing political, security, and economic dimensions, and exposing Baghdad's foreign policy to growing external pressures.