The unilateral authorization of deep seabed mining by states not party to the United Nations Convention on the Law of the Sea (UNCLOS) exposes a critical governance gap. While international law requires all states to cooperate in governing shared resources, the substantive content of cooperative obligation for non-party states in deep seabed mining remains undefined. This article examines the cooperative obligation of non-party states toward the International Seabed Authority (ISA), with particular attention to the unilateral authorization by the United States of deep seabed mining in the Area. Drawing on international jurisprudence, it identifies the boundaries of this obligation and the specific requirements of the cooperative obligation across three dimensions. Environmental cooperation encompasses environmental impact assessment, ongoing monitoring, and pollution control. Resource-related cooperation requires due regard for the interests of other states and equitable consideration of developing states. Scientific and technical cooperation includes data sharing and capacity-building initiatives. It then examines implementation pathways. It demonstrates that UNCLOS dispute settlement mechanisms face jurisdictional obstacles when applied to non-party states, examines the potential of advisory opinions from international judicial bodies to clarify cooperative duties, and discusses complementary enforcement mechanisms, including ISA institutional measures and market-based compliance tools adapted from fisheries governance. The cumulative interaction of these pathways constrains unilateral conduct even without formal treaty ties. The article establishes a conduct-based compliance approach that renders this obligation assessable through benchmarks. It further reveals that traditional positive economic incentives for cooperation fail in deep seabed mining, requiring a shift toward negative incentives based on reputational, institutional, and market costs. More importantly, it identifies an exception to the principle that treaties bind only their parties when applied to global commons governance.
Luo et al. (Mon,) studied this question.