Despite decades of effort, the international community has stumbled in attempts to craft tort remedies for victims of transboundary environmental damage. More than a dozen civil liability treaties have been negotiated that create causes of action and prescribe liability rules, but few have entered into force, and most remain unadopted orphans in international environmental law. In this Article, I explain the problematic record of tort liability regimes by developing a theoretical model of liability negotiations grounded in regime theory from political science. Based on this model, I conclude that negotiated liability regimes have foundered because of three main roadblocks: (1) interest conflicts between developed and developing states; (2) high transaction costs and low expected payoffs; and (3) incorporation of treaty provisions that are too onerous for states to accept. I conclude that strengthening tort remedies will require changing the substantive content of liability treaties and the process of negotiating them. I also show how liability principles can be strengthened outside the treaty-making process through diffusion of norms against transboundary environmental damage.