Marine litter is a global and transboundary pollution problem. Recent attention has focused on the impact of this issue on areas beyond national jurisdiction. In many cases, marine litter is traced to a coastal State where debris have been released into the sea. Effective and legally-binding commitments at the global level to tackle land-based sources of marine pollution are rare, in large part because of the sensitive nature of territorial sovereignty. When it comes to addressing the marine plastics crisis, sovereignty is a double-edged sword. On the one hand, the international legal regime traditionally addressing marine litter, the United Nations Convention on the Law of the Sea, does not specifically respond to, and is not able to adequately address, the issue of plastics as a land-based source of marine pollution. While it contributes to social equity by recognizing the special position of developing States in terms of capacity and need for economic development, this deference to domestic decisions is not conducive to the adoption of binding and global standards. Since a large majority of plastics in the oceans originate from land, this weakness is a major concern. On the other hand, sovereignty might contribute to a solution within the regime regulating trade in waste products: unilateral actions taken in application of sovereign powers and aimed at reducing trade in plastic waste led to major multilateral actions with the potential to reduce the issue of marine plastic pollution. In recent times, the Basel Convention on the Control of Transboundary Movements of Hazardous Waste and their Disposal has indeed become an important forum to respond to the plastic waste issue, with the potential to contribute to a solution to the marine dimension of this crisis. This regime is not perfect, especially in that its complexity and reliance on enforcement at the customs level leave ample opportunities for criminal activities to flourish. Areas for improvement include addressing the legal uncertainty regarding bilateral, regional, and multilateral agreements as well as certain key definitions; strengthening the prior informed consent procedure and the Mechanism for Promoting Implementation and Compliance; and heavily investing in capacity building and technology transfer. Nonetheless, this regime provides a widely-ratified framework to decrease trade in plastic waste considered hazardous or requiring special consideration – these two categories cover most hard-to-recycle plastics. In that sense, the Basel Convention regime has the potential to reduce mismanaged plastic waste leaking into the oceans and to contribute to social equity between States–if not domestically–by reducing the practice of wealthy countries using developing States as dumping grounds under the pretense of mutually beneficial trade in waste products.