Abstract
This paper examines critically various theoretical and conceptual approaches to the analysis of interactions between neighboring border regions. As an important indicator of the degree of rapprochement between nations, the nature and significance of evolving transboundary cooperation in Western Europe and along the U.S.-Mexico border are considered. Despite barriers raised by national governments, such cooperation has been extensive at the regional and local levels. Suggestions are made for research that would contribute to a better under-standing of the processes that foster transboundary cooperation.