A glance at the map and the geopolitical smoke spewing out of the latest U.S.– North Korean nuclear standoff suggests why Northeast Asia (NEA) is among the world’s most important yet volatile regions. For over a century, geography and history have combined to turn the Korean peninsula into a highly contested terrain that has absorbed and reflected wider geopolitical struggles and even sanguinary wars involving, to varying degrees, tsarist Russia, Meiji Japan, the Soviet Union, Qing China, the People’s Republic of China, imperial Japan, and the United States. Each of the Big Four of Northeast Asia (China, Japan, Russia, and the United States, hereafter the NEA-4) has come to regard the Korean peninsula as the strategic pivot point of Northeast Asia security and therefore as falling within its own geostrategic ambit.1 Complicating matters is the fact that the Korean peninsula is divided, meaning that the NEA-4 cannot address the threats and opportunities inherent on the peninsula without paying heed to inter-Korean relations, and also that the seemingly local and bilateral relations between the two Korean states are, in reality, part of the nexus of great-power politics.