A vital text for understanding the twenty-first-century battlefield and the shifting force structure, this book prepares students to think critically about the rapidly changing world they'll inherit. American Defense Policy, first published in 1965 under the leadership of Brent Scowcroft, has been a mainstay in courses on political science, international relations, military affairs, and American national security for more than 50 years. This updated and thoroughly revised ninth edition, which contains about 30% all-new content, considers questions of continuity and change in America's defense policy in the face of a global climate beset by geopolitical tensions, rapid technological change, and terrorist violence. The book is organized into three parts. Part I examines the theories and strategies that shape America's approach to security policy. Part II dives inside the defense policy process, exploring the evolution of contemporary civil-military relations, the changing character of the profession of arms, and the issues and debates in the budgeting, organizing, and equipping process. Part III examines how purpose and process translate into American defense policy. This invaluable and prudent text remains a classic introduction to the vital security issues the United States has faced throughout its history. It breaks new ground as a thoughtful and comprehensive starting point to understand American defense policy and its role in the world today. Contributors: Gordon Adams, John R. Allen, Will Atkins, Deborah D. Avant, Michael Barnett, Sally Baron, Jeff J.S. Black, Jessica Blankshain, Hal Brands, Ben Buchanan, Dale C. Copeland, Everett Carl Dolman, Jeffrey Donnithorne, Daniel W. Drezner, Colin Dueck, Eric Edelman, Martha Finnemore, Lawrence Freedman, Francis Fukuyama, Michael D. Gambone, Lynne Chandler Garcia, Bishop Garrison, Erik Gartzke, Mauro Gilli, Robert Gilpin, T.X. Hammes, Michael C. Horowitz, G. John Ikenberry, Bruce D. Jones, Tim Kane, Cheryl A. Kearney, David Kilcullen, Michael P. Kreuzer, Miriam Krieger, Seth Lazar, Keir A. Lieber, Conway Lin, Jon R. Lindsay, Austin Long, Joseph S. Lupa Jr., Megan H. MacKenzie, Mike J. Mazarr, Senator John McCain, Daniel H. McCauley, Michael E. McInerney, Christopher D. Miller, James N. Miller, John A. Nagl, Henry R. Nau, Renée de Nevers, Joseph S. Nye Jr., Michael E. O'Hanlon, Mancur Olson Jr., Sue Payton, Daryl G. Press, Thomas Rid, John Riley, David Sacko, Brandon D. Smith, James M. Smith, Don M. Snider, Sir