How has the Republic of Korea (ROK) both shaped and advanced Korean unification? This chapter employs a historical-institutional approach to examine how Seoul has sought external support to back its unification objectives, going from utilising one-way broadcasting systems in the early 1950s to a relational, networked, and digital public diplomacy nowadays. To do this, the research is organised along five stages: post-liberation legitimacy; development strength and security; democratisation and internationalisation, from Sunshine to Strategic Patience; and global framing and identity politics. The chapter demonstrates that the DPRK has constructed a strategic narrative that engages with institutions and stakeholder coalitions, while also contending with the National Security Law and political shifts.