The current balance of power in East Asia as can best be characterized as two great powers and two second-rank great powers. The two great powers are the United States and China; the two second-rank great powers are Japan and Russia, which are dependent for their security on the support and forbearance of a great power. In contrast to the U. S.-Soviet Cold War balance of power, the U. S.-China bipolar balance of power is relatively stable. Due to the distinct interests and capabilities of China and the United States, the bipolar structure of the twenty-first century East Asian balance power will allow the great powers to manage their conflicts of interests with minimal instability. Nonetheless, there remains the potential for instability and heightened great power tension. One potential source of instability is the inability of the two great powers to manage their respective weaker partners-North Korea and Taiwan. The second potential source of instability is fluidity in power relationships among the four great powers and the resulting prospects for strategic change and a transformation of the current structure of the balance of power.