During the 1960s and 1970s, Southeast Asia was referred to as the Balkans of Asia. The region has, however, gone through significant transformations and seen peaceful change since the end of the Cold War despite ongoing great-power interference, the rise of China as a military and economic power, and a series of territorial disputes including the South China Sea issue. This chapter explores the historical and institutional bases that have contributed to the process of peaceful change in Southeast Asia. It argues that peaceful change has evolved and been maintained by the Southeast Asian states by adopting strategies that combine the realist, liberalist, and constructivist approaches. The chapter concludes by discussing the changing nature of security challenges and how the region has been responding to these threats.