Abstract:In this article, we critically examine the widely held view that transboundary political and legal efforts to reduce pollution of the river Rhine by heavy metals have been a success story. In doing so, we seek to contribute to the analysis of the performance of transboundary environmental cooperation, and to gain insights that may be relevant to environmental cleanup efforts in other international river basins. We conclude that international efforts have only modestly and indirectly contributed to pollution reductions, and that, in the Rhine case, informal approaches to problem solving have been more effective than formal approaches. We also find that liability frameworks may contribute toward pollution reductions, but are, even under favorable conditions, of very limited effectiveness.