The signature trait of US foreign policy since the end of the Cold War has been the denial of regional spheres of influence to other great powers – mainly Russia and China. Spokespeople for successive administrations have consistently denied the legitimacy of Russian claims of privilege in Eastern Europe and Chinese claims of privilege in its various maritime approaches. They have also denied the relevance and propriety of the idea that any powerful countries should have interests in the geopolitical orientations of their neighbors. In the rules-based international order, the argument goes, other great powers have nothing to fear from their neighbors and should focus their efforts on economic development or – better yet – political reform. This attitude suffuses the trans-Atlantic foreign policy establishment and traces its strongest roots to the so-called “lesson of Munich,” the idea that the concession of a sphere of influence to Nazi Germany ended in catastrophe. Yet not only does the concept remain relevant in the minds of many non-Anglo-American statesmen, advances in military technology and shifts in the global balance of power are strengthening the case for restoring it as a proper fixture of American foreign policy making. Over the next couple of posts I will explore the continuing relevance of spheres of influence and make the argument that no prudent future American foreign policy can fail to recognize their importance.