This thesis examines how states deal with the complex issues of cross-border data governance in an era where digital infrastructure intersects with national security. For this purpose, it offers a comparative analysis of two emblematic cases: the U.S....
This thesis examines how states deal with the complex issues of cross-border data governance in an era where digital infrastructure intersects with national security. For this purpose, it offers a comparative analysis of two emblematic cases: the U.S. government’s aggressive legal actions to force the divestment of TikTok’s Chinese ownership, and the Japanese government’s more restrained administrative intervention in the operations of LINE, following massive information leakage related to South Korea’s NAVER. Applying a constructivist-realist lens, the study argues that data sovereignty has evolved into a key aspect of economic security, shaped by strategic interests, national identity, and institutional practices. The U.S. employed a form of ‘overt securitization,’ marked by legal measures such as the RESTRICT Act and political discourse framing the Chinese platform as an existential threat. Japan adopted ‘quiet securitization,’ using non-binding administrative guidance to pressure LINE to localize data infrastructure and reduce its dependence on NAVER, without imposing formal penalties. These contrasting strategies reflect different governance styles: the U.S. favors legal formalism and open confrontation, whereas Japan relies on informal, flexible bureaucratic practices. South Korea’s restrained response further highlights the region’s strategic diversity, contrasting sharply with China’s firm defense of TikTok. Based on these findings, the study offers policy recommendations to enhance South Korea’s digital diplomacy and sovereignty. More broadly, it demonstrates how trust, identity, and political narratives shape digital governance in East Asia. Without building trust and shared rules, unilateral securitization may deepen regional divisions rather than resolve them.