How does the United States resource war? What are some of the lessons DOD comptrollers have learned since 9/11? What actions should senior leaders take now to better prepare for future conflict? These questions serve as the foundation of this analysis on some key financial aspects of America's ongoing fight against violent extremism. Resourcing War offers a basic overview of DOD's resourcing process, including the important distinction between baseline and contingency costs. A survey of the post-9/11 resource response and some of the new challenges faced by deployed comptrollers is followed by a brief overview of the progress made in eight years of war. The analysis offers three broad conclusions-deployed commanders must focus on issues of financial cost at the appropriate time, comptrollers should improve budget outcomes by continuously preparing for their wartime role, and DOD leaders must leverage cash on the battlefield in ways commensurate with its proven value. Sources for Resourcing War including eyewitness accounts from periodicals, interviews, and the author's own deployed experience. Historical examples from war, ancient and modern, enrich the discussion.