The main purpose of this article is to examine the overall nature and broad aspects of the political economic impacts of the American re-engagement in the EAS and East Asian regionalism. It posits that a series of complicated structural factors such as the complexity of the structure of East Asian political economic landscape, the rise of China and drastic changes in the East Asian power structure, the shifts of the US political influence and roles in the East Asian region may affect the nature and aspects of the impacts of the US reengagement. The main argument of this essay is that the overall feature of East Asian regionalism may show the aspects of the G2-nization between the two super powers for the time being, but the detailed aspects and achievements of regional cooperation will be varied depending on the issue areas such as political-security, finance, trade and non-traditional cooperative issues.