The United States has spent—and continues to spend—billions of dollars building Iraq’s military capabilities. Despite that fact, Iraq’s military performance, even after wresting control of its territory from the Islamic State, remains inconsistent at best. A survey of Iraqi military history suggests a pattern of strengths, weaknesses, and performance that includes courageous soldiers, cohesive units, incompetent leaders, divided loyalties, poor combat support, and weak institutions that have, on occasion, risen to the defense challenge. If the United States is going to be more successful in developing Iraqi military capabilities, it will need to change its approach to better account for the Iraqi Army’s culture, history, and political environment. The United States will also have to be clear regarding the purpose of this cooperation. Security cooperation with Iraq is not just about defeating the Islamic State or other terrorist groups. The United States stands to gain when Iraq can play a constructive security role as an accepted member of the broader regional and international community. Iran cannot get the Iraqi military to that point, but the United States can. Thus, the long-term goal of US security cooperation with Iraq should be to establish its military as a valuable security partner, capable of participating in regional security arrangements, much in the same way Jordan, Saudi Arabia, and even Oman does. Of course, getting to that point depends on political developments the United States has limited ability to influence, much less control. Having said that, continued, steady engagement emphasizing the critical areas of development should serve to set conditions for meaningful improvement when political and social conditions permit. While no single measure is going to improve the Iraqi Army, taken together, the right combination give the Iraqi Army a chance to achieve a “tipping point” that enables the kind of reform that can allow it to get beyond its historic limitations.