Root cause analysis is a methodical approach in identifying and comprehending the associated underlying causes of specific problems and implementing the best possible solutions. Positive peace is anticipated under this approach by preventing structural and cultural transgressions and ensuring a culture of accountability, responsibility, mutual trust, and understanding among the parties involved. This chapter goes into greater detail about how much the identification of the underlying causes is taken into account when working on positive peacebuilding in Aceh, Indonesia, in the aftermath of the conflict. The case of Indonesia due to the associated underlying causes of ethnic and religious identities as well as the incidence of structural and cultural transgressions throughout the conflict phase, Aceh becomes one of the ideal cases for this debate. As a result, this chapter focuses mostly on Aceh’s post-war period and discusses both the positive and negative actions made to bring about positive peace at this time. However, there is anticipated to be an overall discussion about the type of cooperation policy that the Indonesian central government and Acehnese local government should have in order to ensure and preserve the positive peace within Acehnese society.