Widely regarded as "The Oldest Military Treatise in the World," this compact little book, written more than 2,500 years ago, today retains much of its original authoritative merit. American officers during World War II read it closely. The Japanese army studied the work for decades, and many twentieth-century Chinese officers are said to have known the book by heart. Maintaining that "all warfare is based on deception" and that "in war . . . let your great object be victory, not lengthy campaigns," the author adds: "That general is skillful in attack whose opponent does not know what to defend; and he is skillful in defense whose opponent does not know what to attack." Principles of strategy, tactics, maneuvering, communication, and supplies; the use of terrain, fire, and the seasons of the year; the classification and utilization of spies; the treatment of soldiers, including captives, all have a modern ring to them. The author even provides rules for the "blitzkrieg," prefacing them with the words that "rapidity is the essence of war." Still a valuable guide to the conduct of war, this volume will be indispensable to military students and of interest to all those fascinated by military history. Unabridged republication of the edition published by The Military Service Publishing Company, Harrisburg, Pennsylvania, 1944.