This book provides a comprehensive study of America's infantry combat performance in Europe during World War n, showing that the Army succeeded by developing combat effective divisions that could not only fight and win battles, but also sustain that effort over years of combat. While American industry admittedly enabled the U.S. to sustain its overseas armies, the effectiveness of those forces ultimately rested on their organizational capabilities and ability to adapt to combat in a variety of lethal environments and to learn from their mistakes.

Mansoor analyzes the impact of personnel and logistical systems on the Army's strength, explaining how leaders used these systems to keep a small number of divisions at a high state of combat effectiveness. During the, critical battles of 1944-45, American divisions were able to sustain this high level while their Wehrmacht counterparts disintegrated, demonstrating that the Army's endurance in extended combat was the most critical factor in its ultimate success. Mansoor also takes a close look at the personalities and capabilities of division commanders, infantry tactics and operations, logistics, and the benefits and weaknesses of stateside training.

TheAmerican army won, asserts Mansoor, because unit for unit at the division level it was more effective than its adversaries. By showing how U.S. infantry developed more quickly and fought better than commonly believed, The GI Offensive in Europe contributes significantly to the history of the U.S. Army in the European theater and to our overall understanding of military effectiveness.