The river basin is no longer the appropriate spatial unit for analysing water problems. With increasing trade between nations and continents, water is more and more often used to produce goods that are exported. This book analyses this issue for the first time on a global scale. It addresses questions such as: Is the import of water in virtual form � in the form of imported commodities � a solution to water scarce countries? What threats are there in countries becoming �water dependent�? Can international trade be a tool to enhance global water use efficiency, or is it a means of shifting the environment burden to a distant location? The book shows the water footprint of nations, a consumer based indicator of water use which can be used as a tool to understand the impacts of local consumption on global water resources and the dependency of any country on external water resources.