We shall not cease from exploration And the end of all our exploring Will be to arrive where we started And know the place for the first time. —T.S. Eliot, “Little Gidding” Not learning from wars can be catastrophic. The next cohort of national security leaders may not achieve the sublime mental state envisioned by T.S. Eliot, but they must make every effort to learn the lessons of the Long War. For that reason, in his second term’s Strategic Direction to the Joint Force, Chairman of the Joint Chiefs of Staff General Martin E. Dempsey charged senior officers “to apply wartime lessons learned to provide best military advice and inform U.S. policy objectives and strategic guidance. Major General Gregg F. Martin, USA, then–President of National Defense University (NDU), wrote:In addition to continuing to analyze and teach the lessons of past conflicts, [NDU] must research, disseminate, and teach the strategic and operational lessons of over 10 years of war. These efforts will play an important role in both improving the quality of strategic leadership and performance of our graduates and contributing to new national and military security strategies and innovative operational concepts to meet emerging needs.This volume represents an early attempt at assessing the Long War, now in its 14th year. Forged in the fires of the 9/11 attacks, the war includes campaigns against al Qaeda, major conflicts in Iraq and Afghanistan, and operations in the Horn of Africa, the Republic of the Philippines, and globally, in the air and on the sea. The authors herein treat only the campaigns in Afghanistan and Iraq, the largest U.S. efforts. It is intended for future senior officers, their advisors, and other national security decisionmakers. By derivation, it is also a book for students in joint professional military education courses, which will qualify them to work in the field of strategy. While the book tends to focus on strategic decisions and developments of land wars among the people, it acknowledges that the status of the United States as a great power and the strength of its ground forces depend in large measure on the dominance of the U.S. Navy and U.S. Air Force in their respective domains. This assessment proceeds from two guiding sets of questions about the wars in Iraq and Afghanistan. The core set of questions was suggested by the Chairman of the Joint Chiefs: What did we gain? What did we lose? What costs did the United States pay for its response to 9/11, particularly from operations in Afghanistan and Iraq? How should the answers to these questions inform senior military leaders’ contributions to future national security and national military strategy? The second set of questions proceeds from the first: what are the strategic “lessons learned” (or “lessons encountered,” as the British and the authors of this work prefer) of our experience in Operation Enduring Freedom (OEF) in Afghanistan, and Operations Iraqi Freedom (OIF) and New Dawn in Iraq.