This chapter examines the proliferation of cross-border data transfer restrictions adopted on national security grounds, analyzes their legal implications under international economic law, and proposes solutions. While prior analyses have focused on privacy-based restrictions under WTO and FTA frameworks, this chapter demonstrates through case studies of China, the United States, and Japan that security-based measures are rapidly expanding. China’s expansive national security conception and use of domestically held data for security and industrial purposes have prompted the US and Japan to intensify their own transfer restrictions. The chapter identifies key legal and systemic concerns including transparency deficits, regulatory fragmentation, data re-export risks, and potential WTO/FTA incompatibilities. Drawing analogies to export control regimes for goods, the chapter argues that frameworks like the Wassenaar Arrangement offer valuable guidance for addressing these challenges through common control lists, enhanced information sharing, and convergence in restriction design. It concludes by proposing a forum among like-minded states to facilitate policy coordination between export control and digital regulation communities.