In this timely book, military expert Michael O'Hanlon examines America's major conflicts since the mid-1800s: the Civil War, the two World Wars, Korea, Vietnam, Iraq, and Afghanistan. O'Hanlon looks for overarching trends and themes, along with the lessons for the military strategists and political leaders of today and tomorrow.

Michael O'Hanlon holds the Phil Knight Chair in Defense and Strategy at Brookings, where he also is director of research and director of the Talbott Center in the Foreign Policy Program. He teaches at Columbia and Georgetown universities and elsewhere. Earlier in his career, O'Hanlon worked for the Congressional Budget Office, the Peace Corps, the "gravity group" at Princeton University, and dairy farms in upstate New York. He is the author of some 20 books, most recently The Art of War in an Age of Peace: U.S. Grand Strategy and Resolute Restraint (Yale, 2021).