The tensions between the Koreas--and the potential involvement of China, Japan, Russia, and the United States in a Korean conflict--create a nearly open-ended spectrum of possible conflicts. These conflicts could range from posturing and threats to a major conventional conflict on the Korean peninsula, with intervention by outside powers, to the extreme of nuclear conflict. The Korean balance is also affected by the uncertain mix of cooperation and competition between the United States and China, particularly with the U.S. "pivot" toward Asia and the steady modernization of Chinese forces. This new volume, up to date through Spring 2015, provides a detailed examination of the military forces in Northeast Asia--North and South Korea, China, Russia, Japan, and the United States--setting those forces in the larger geostrategic context.