This chapter explores the formation of national identity in Viet Nam and Indonesia by examining the lasting influence of colonialism on these two post-colonial states. Through three guiding questions derived from post-colonial nationalism research, it assesses how the colonial experience has shaped both countries’ identities and their approach to foreign policy. The analysis focuses on three key issues: (1) whether Viet Nam and Indonesia existed as nations before European colonisation or if colonial powers defined their borders and memberships; (2) how the systems established after independence shaped national identity; and (3) the impact of the Cold War on the development of post-colonial national identity in each country. The findings demonstrate that the colonial experience continues to play a central role in both nations’ political narratives, particularly in how elites address colonialism and frame trade relations with Europe. The chapter highlights the importance of understanding the interplay between historical legacies and national identity in shaping contemporary foreign policy. It offers insights into how post-colonial states like Viet Nam and Indonesia steer their relationships with the EU. These results provide a deeper understanding of the role of nationalism in international relations, particularly in post-colonial contexts.