This article explores the intersection of data sovereignty and international trade law, focusing on how national data-localization frameworks impact global trade dynamics and digital market competitiveness. As cross-border data flows become essential for economic growth, countries are increasingly asserting sovereign control over digital assets, which creates tensions with international trade obligations. The study examines how countries balance data sovereignty measures with the need for open trade and free movement of digital services. Drawing on a comparative legal analysis of ten jurisdictions, the research integrates multi-criteria decision modeling to assess the effectiveness of regulatory frameworks, enforcement mechanisms, and the economic impact of data policies on digital trade. The results indicate that countries with low-latency networks, treaty-compatible statutes, and frequent legislative updates achieve the highest digital trade performance scores. In contrast, nations with high-intensity localization measures face elevated risks of trade penalties, reduced foreign investment, and significant technical bottlenecks. The study concludes that institutional agility—measured by frequent statutory revisions—emerges as a stronger predictor of compliance and investor confidence than market size alone. Policy recommendations include the need for data-transfer monitoring systems and firm-level network-performance disclosures to support evidence-based regulation and improve international digital governance. This study provides a reproducible framework for future research and policy evaluation, emphasizing the critical role of data sovereignty in shaping the future of global digital trade.