Colonialism in a way can be defined as the period in which colonization - the process of a powerful country's settling among and establishing control over the indigenous people of another area for the economic exploitation of the area's natural resources and land - occurred. Many historians typically associate European countries as being the main perpetrators of colonization. This is indeed accurate since Europe spent 500 years of its history engaging in colonial conquest beginning with the age of exploration - the period, in which Europeans discovered that there were other people and countries in the world through state-sponsored sea voyages - in the fifteenth century until the end of the twentieth century with the aftermath of World War II, in which European countries were forced to decolonize through the introduction of many treaties. This book explores new challenges on postcolonial Southeast Asian states which reveal a significant amount of change since the achievement of independence.