The Legacy of the Shatt al-Arab Waterway Dispute in Post-2003 Iran-Iraq Relations

The Shatt al-Arab waterway, a historically contested boundary between Iran and Iraq, has long been a focal point of regional tension, contributing to the outbreak of the 1980–1988 Iran-Iraq War and shaping bilateral relations throughout the 20^th century. This article aims to examine the legacy of the Shatt al-Arab dispute in the post-2003 period, following the fall of Saddam Hussein. It investigates how the historical tensions over territorial sovereignty, navigation rights, and treaty obligations have persisted or evolved within the broader framework of Iran-Iraq relations under new political realities. The findings suggest that while the Shatt al-Arab has not re-emerged as a flashpoint for open conflict, it remains a latent source of mistrust and strategic calculation. Post-2003 dynamics have been characterized by fluctuating cooperation and competition, shaped by broader sectarian alignments, political instability in Iraq, and Iran's growing regional influence. Efforts at diplomatic normalization—such as joint border commissions and navigation protocols—have been undermined by security concerns and unresolved treaty legacies, particularly regarding the 1975 Algiers Agreement. Utilizing a qualitative methodology, this study draws upon primary sources such as diplomatic statements, official agreements, and UN records, alongside secondary sources including scholarly literature and policy analyses. The article employs a historical-institutionalist approach to trace the continuity and transformation of bilateral norms and practices related to the waterway. The article concludes that the ‘Shatt al-Arab’ dispute continues to act as both a symbol of unresolved historical grievances and a potential site for future diplomatic engagement. Its legacy underscores the need for institutionalized mechanisms of conflict resolution and cross-border environmental governance in the Iran-Iraq relationship.