Over the past few decades, the Asia-Pacific region has become an emerging new power center, thanks not only to its rapid economic development but also to integration among the nations of the region. ASEAN has been playing a key leading role in this process, especially in fostering the linkage between Southeast Asia, Northeast Asia, and South Asia. Why and how has ASEAN been able to play this leading role? This chapter argues that ASEAN has been playing this role by initiating and leading a series of mechanisms in the Asia-Pacific. This role of ASEAN is not only motivated by factors such as economics, politico-security, and cultural identity, but also by the fact that ASEAN has many advantages of its own.