The departure of the final U.S. troops from Iraq last week marks the end of a more than two-decade-long American military presence in the country, closing a chapter that has left enduring questions about the consequences and costs of the 2003 invasion. Over 23 years, more than 1.5 million American service members have been deployed in Iraq, with the last contingent of approximately 1,500 personnel recently withdrawn.

Initial hopes that the invasion would catalyze democratic reform in the Middle East proved overly optimistic. Early experiences underscored the challenges of the occupation. In August 2003, during his first visit to Iraq, a correspondent accompanied a Marine Force Reconnaissance unit on a mission that was disrupted by an improvised explosive device (IED). The incident exposed operational shortcomings, including a shortage of interpreters and understaffing, reflecting a broader lack of preparedness and understanding of the complex Iraqi environment.

Over the following years, conditions deteriorated, with increased violence and instability manifesting through repeated bombings and ambushes. Security measures adapted accordingly, progressing from unarmored vehicles to heavily fortified Mine-Resistant Ambush Protected (MRAP) vehicles. Although U.S. troops demonstrated professionalism and dedication, commanders' optimistic reports often conflicted with the persistent insecurity on the ground. Rotating units frequently portrayed their predecessors’ efforts as flawed while asserting progress under their watch, contributing to skepticism about official assertions of success.

The mission's focus gradually shifted toward sustaining the extensive military infrastructure required to maintain American forces, with some troops expressing frustration over the limited impact of their deployment beyond logistical support and base defense. The intricate web of Iraq’s tribal, ethnic, and political divisions further complicated efforts to stabilize the country, challenging simplistic narratives that cast the conflict as a clear struggle between allies and adversaries.

Concerns over a premature U.S. withdrawal led to support for the 2007 troop surge, which aimed to enhance population security rather than merely pursuing insurgents. This strategy saw significant reductions in violence. However, the 2011 withdrawal of American combat troops during the Obama administration ultimately created a power vacuum that facilitated the rise of the Islamic State (ISIS). The group’s expansion necessitated a renewed U.S. military presence in 2014, albeit on a smaller scale and with a supporting role for local forces.

The recent pullout leaves unresolved issues, notably the sustained influence of Iranian-backed militias, which were expected to be disarmed as part of the U.S. departure but remain active. The presence of American forces, even in limited numbers, had served as a counterbalance to this influence.

Reflecting on the two decades of involvement, the conflict is widely regarded as a costly endeavor—financially, militarily, and in human lives—without yielding clear strategic advantages. While Iraq today is more peaceful and experiencing economic recovery compared to its recent past, the invasion’s long-term effect was to solidify Iranian power in the region.

The experience has prompted reevaluation of U.S. interventionist policies, fostering greater caution about nation-building efforts abroad and skepticism about the efficacy of military solutions to complex foreign conflicts. Despite this, recent signals of increased U.S. military deployments in the Middle East suggest that the lessons of Iraq may not have fully tempered policymakers’ approaches to regional security challenges.