This study examines national security strategy. There is no word or phrase more important and essential to the national security community than "strategy." In this monograph, Dr. Tami Davis Biddle argues that, while most of us have a sense of what the word means, we do not always fully appreciate all that it entails and all that it demands of us. Indeed, she argues that because strategy is so difficult on so many levels, we must not delude ourselves into believing that it can be practiced in any idealized form. But she insists that in situations where lives are at stake, we have a moral obligation to do all we can to meet the wide array of challenges we must face as we devise and implement strategies (and grand strategies) to achieve desired political ends. Dr. Biddle begins her monograph with a close examination of the terms "strategy" and "grand strategy." Relying on a wide body of literature by historians, political scientists, and practitioners, she examines the reasons why political actors adopt strategies and grand strategies, and she helps us understand how the terms have been used — and have evolved — over time. She observes that the way in which strategies and grand strategies have been developed and implemented by actors in the international system has followed a narrative arc determined largely by the changing character, over time, of social, political, and military organizations. Relying on this definitional and historical groundwork, Dr. Biddle articulates the myriad reasons why the practice of strategy is such a difficult and demanding art. She argues that strategy requires a logic that can be explained and defended, but points out that often this logic rests on assumptions that have not been thoroughly and rigorously examined. She argues that, even when the logic of strategy makes sense, its implementation will be eroded and undermined by contending interests and bureaucratic politics; unforeseen and unanticipated events; the pressures of domestic politics; the limits of human cognition, attention, and endurance; and the ongoing challenges posed by civil-military interaction. Dr. Biddle's clear-headed examination of strategy, which is full of useful examples and sober guidance, will sharpen the analytical skills and deepen the situational awareness of students and practitioners alike.