This groundbreaking work explores how globalization, technological advances, and economic integration have created a world where states are deeply interconnected across multiple domains—economics, communications, and security. Keohane and Nye argue that international relations can no longer be explained solely through the lens of military power and zero-sum competition. Instead, they introduce a spectrum: at one end, the realist “ideal type,” where states focus on survival and security; at the other, “complex interdependence,” where states are mutually dependent for their well-being and military force is often irrelevant. The authors distinguish between “sensitivity interdependence” (how quickly changes in one country affect another) and “vulnerability interdependence” (the costs of adjusting to those changes), highlighting that power in the modern world is about setting the rules and managing mutual dependencies. Through historical and contemporary examples—including energy crises, economic policy shifts, and changing international regimes—they demonstrate that issues like trade, environmental protection, and technology now rival security in shaping global politics. The book also critiques simplistic celebrations of globalization, urging readers to analyze the politics and power dynamics embedded within interdependence rather than accept it as an unqualified good.