“Landmines are among the most barbaric weapons of war, because they continue to kill and maim innocent people long after the war itself has ended.” Landmines have been the source of suffering for not only tens of thousands of soldiers, but also thousands of civilians worldwide. They continue to lie dormant in many countries, some hidden in nearby dirt or foliage, until triggered by an unsuspecting victim. In the past twenty years, Amended Protocol II to the Convention on Conventional Weapons and, even more so, the Ottawa Convention—also known as the Mine Ban Treaty—have led to a decrease in the number of mines lingering in nations’ soil and those used in recent conflicts. Although a handful of holdouts to the Ottawa Convention remain, those countries’ refusal to accede to the treaty does not necessarily prevent them from being bound by a number of legal principles it set out to establish. This Note will argue that, due to states’ conduct over the last fifteen to twenty years and their views toward the Ottawa Convention, customary international law has led to the emergence of five new rules severely constraining landmine transfer, development, and use.

Part I will explore the recent legal history of landmines, which consists of Amended Protocol II to the convention on Certain Conventional Weapons and the Ottawa Convention. Part II will discuss customary law, a principal source of international law, and theories regarding its development and applicability. Finally, Part III will dive into the intersection of customary international law, landmines, and how countries’ public statements, actions, and expressed opinions have led to the advancement of new customary laws. This Note concludes that the new laws—binding on all or nearly all nations—include a total ban on landmine transfer, a good faith obligation to work toward Ottawa Convention accession, a ban on the development and use of smart mines, and a prohibition or at least a stringent restriction on the use of persistent mines.