Although geography may be as close to immutable as anything can be in international politics, its strategic significance is hardly static. In fact, as the dynamics of great power politics shift, the strategic significance of geography can also change rapidly. As the cold war ended in Northeast Asia and South Korea emerged as an important actor in the regional scene, the Korean peninsula"s place in the Northeast Asian security equation has changed. For the first time in recent history, developments coming from the peninsula affect the interests of its neighbors and the regional strategic outlook more than the other way around. Korea"s responsibility to regional peace and stability accordingly is greater than ever. Challenges facing the Korean peninsula with far-reaching regional implications are many, but Pyongyang"s nuclear development, North Korea"s uncertain future, and the long-term viability of the ROK-U.S. alliance are most prominent. Obviously, these challenges are closely interrelated. For example, how the current nuclear crisis is resolved would essentially affect the future direction of North Korea. It will also fundamentally affect the presence and role of the United States on the Korean peninsula and in Northeast Asia. Therefore, these challenges should be envisaged and addressed in a comprehensive way. Without the backing of a solid alliance, it is difficult to expect that any of these challenges can be coped with effectively. Failure to respond to the above challenges in turn would entail enormous upheavals in the entire Northeast Asian region. In this sense, strengthening the ROK-U.S. alliance will serve not only the interests of South Korea but those of the entire region. The most important step in coping with these complex challenges, therefore, is to repair, redefine, and revitalize the ROK-U.S. alliance, making it more reciprocal and thus more resilient. This will take vision, leadership, creativity, steadfastness and, not least, courage. It will not be an easy take but surely it will be worth the effort.