This report was initially presented as a paper at the Post-9/11 Irregular Warfare Lessons Learned Conference in Annapolis, Maryland from September 17-18, 2024. The conference was sponsored by FPRI’s Center for the Study of Intelligence and Nontraditional Warfare and the Department of Defense’s Irregular Warfare Center.

Key Points

• The Iraq War offers critical lessons in irregular warfare, particularly regarding the use of local forces, and highlights the challenges in recruiting, training, and coordinating with Iraqi police and militias.
• This study analyzes the long-term consequences of decisions made during the conflict. It examines factors that contributed to the rise of the Islamic State in Iraq and Syria (ISIS) and identifies missed opportunities to prevent its emergence.
• Key takeaways include the necessity of preserving existing security structures unless there is a sufficient occupation force and understanding ideological divisions within the population to identify opportunities for realignment.

Introduction

The aftermath of the 9/11 attacks on the United States prompted numerous counterinsurgency operations across various theaters of conflict. The Iraq War offers a wealth of lessons learned in irregular warfare. This article delves into the successes and failures that characterized US and allied efforts to stabilize Iraq post-2003. It seeks to answer critical questions regarding the utilization and challenges of local Iraqi police and militia forces in counterinsurgency campaigns. It explores how these forces were best utilized and identifies the main challenges encountered in recruiting, training, supplying, communicating with, and operating alongside them. Furthermore, this article aims to distill critical insights that can inform future operations by assessing some of the negative consequences of actions, including several factors that led to the emergence of the Islamic State. It also examines the second-and third-order effects of tactical, operational, and strategic decisions made during the conflict, emphasizing how some long-term consequences could have been avoided with greater foresight and understanding of the political landscape. By reflecting on both the positive and negative outcomes of the Iraqi experience, especially the Sunni Awakening, this study seeks to contribute to a nuanced understanding of modern irregular warfare and the enduring challenges of nation-building in a post-conflict setting.