In its most general sense, grand strategy can be defined as the overarching vision that shapes a state’s foreign policy and approach to national security. Like any strategy, it requires the coherent articulation of the state’s ends and means, which necessitates prioritizing vital interests, identifying key threats and opportunities, and (within certain limits) adapting to circumstances. What makes it truly “grand” is that it encompasses both wartime and peacetime, harnesses immediate realities to long-term objectives, and requires the coordination of all instruments of power (military, economic, etc.). Although American leaders have practiced grand strategic thinking since the early days of the Republic, the concept of grand strategy itself only started to emerge during World War I due to the expansion and diversification of the state’s resources and prerogatives, the advent of industrial warfare, and the growing role of populations in domestic politics and international conflicts. Moreover, it was only during World War II that it detached itself from military strategy and gained real currency among decision-makers. The contours, desirability, and very feasibility of grand strategy have inspired lively debates. However, many scholars and leaders consider it a worthy (albeit complex) endeavor that can reduce the risk of resource-squandering, signal intentions to both allies and enemies, facilitate adjustments to international upheavals, and establish a baseline for accountability. America’s grand strategy evolved from relative isolationism to full-blown liberal internationalism after 1945. Yet its conceptualization and implementation are inherently contentious processes because of political/bureaucratic infighting and recurrent dilemmas such as the uncertain geographic delimitation of US interests, the clash of ideals and Realpolitik, and the tension between unilateralism and multilateralism. The end of the Cold War, the 9/11 attacks, China’s rise, and other challenges have further compounded those lines of fracture.