War and Power: Who Wins Wars―and Why Hardcover – October 28, 2025

A bold, revisionist study of modern warfare, showing that military victory is rooted not in large armies and decisive battles, but in the full spectrum of economic, political, and social power“Stimulating. ... Full of interesting facts and connections.” —Wall Street Journal For nearly two centuries, international relations have been premised on the idea of the “Great Powers.” As the thinking went, these mighty states—the European empires of the nineteenth century, the United States and the USSR during the Cold War—were uniquely able to exert their influence on the world stage because of their overwhelming military capabilities. But as military historian Phillips Payson O’Brien argues in War and Power, this conception of power fails to capture the more complicated truth about how wars are fought and won.  Our focus on the importance of large, well-equipped armies and conclusive battles has obscured the foundational forces that underlie military victories and the actual mechanics of successful warfare. O’Brien suggests a new framework of “full-spectrum powers,” taking into account all of the diverse factors that make a state strong—from economic and technological might, to political stability, to the complex logistics needed to maintain forces in the field.  Drawing on examples ranging from Napoleon’s France to today’s ascendant China, War and Power offers a critical new understanding of what makes a power truly great. It is vital reading in today’s perilous world. Read more