This paper delves into a historical analysis of Sino-Korean relations in pre-modern Asia through the lens of bandwagoning theory within the field of International Relations. It scrutinizes the diplomatic shifts experienced by Goryeo, a Korean kingdom, during the tumultuous power struggle between the Khitan Liao and Jurchen Jin dynasties in Northern China. The paper challenges the prevailing assumption that balancing was the sole "reasonable" option for Goryeo, arguing instead that the kingdom's strategic decision to establish tributary relations with the Jin, adopting a position of subservience, was driven by a calculated pursuit of its national interests. It highlights that Goryeo's bandwagoning strategy yielded tangible security benefits, including territorial expansion, reduced military tensions, and integration into the new international order established by the revisionist state. The paper reaffirms the realist perspective, emphasizing that the pursuit of national interests compels states to consider foreign policy options in response to structural factors shaping the international landscape.