This book studies the law of occupation, historical case studies on occupation, and the current U.S. doctrine on occupation. An analysis formed from the current international law, Hague Convention Number IV Respecting the Laws and Customs of War on Land, 18 October 1907 and the Geneva Convention Relative to the Protection of Civilian Persons in Time of War, 12 August 1949, shows five essential tasks for the execution of an occupation. The book of three historical case studies, Germany post-World War II, Panama 1989-1990, and Iraq 2003, shows four additional essential tasks and other considerations for an occupation. The book then examines Joint and Army specific documents for their treatment of the mission of occupation. The monograph succinctly proves that there is a lack occupation doctrine. The book concludes by synthesizing the essential tasks from the law and the historical case studies into a model that could be used to develop doctrine for future occupations. The book identifies shortfalls in current doctrine and recommends critical changes. These changes, if adopted will ensure that the U.S. military is better prepared to execute the occupation mission following future conflicts, and will serve the very real needs facing the nation today.