After the collapse of the Six-Party Talks in 2008 and the confrontational setting of 2009-12 when Sino-South Korean relations were mostly troubled, a new dynamic has emerged in the China-South Korea-U.S. triangle under Xi Jinping, Park Geun-hye, and Barack Obama. In this chapter I review earlier dynamics over a quarter century, assess the triangle as recently seen from each of the three corners, and reflect on the challenges that lie ahead that could alter the current dynamics. In the shadows of this triangle is North Korea, whose policies continue to exert a decisive impact.